Course 1.

Animal diets sources

In animal diets can be used a variety of sources (feeds), which are mainly
of vegetable origin and animal origin.
Synthetic amino acids, mineral supplements, vitamin supplements, and other
additives can be added alongside basic feeds to prepare complete diets for animals.
The most used criterion of classifying the nourishment sources of animals
is based on their nutritional density.
From this point of view, feeds can be delimited into: (α) volume feeds
(presented first) and (β) concentrate feeds (presented afterwards).

α. Volume feeds

Volume feeds in the natural state (not by reference to the dry matter content)
have lower nutritional values, compared to concentrate feeds.
The most important sources of volume feeds in their priority of presentation
are:
* Green fodders
* Silages
* Hays, artificially dried forages and straws
* Roots, tubers and their by-products

Green fodders

Green fodders are the basic nourishment sources in the warm seasons for
herbivores.
First of all, green fodders are characterized by high water content (70-85%),
the one that induces high intake, high digestibility, diuretics and dietetics effects.
Green fodders have good energy and protein nutritional values, they are
excellent sources of vitamins and minerals, contributing decisively to maintaining
the health of the animals and to achieve production. Also, there are the cheapest
sources of feeds, positively influencing the cost price of animal products.
Green fodders can be obtained from pastures (grasslands) and fodder crops.
 Pastures

The pastures occupy the largest share of Europe's agricultural area, about
33% (or 56 million hectares).
Technically speaking, the simplest pastures are those which have only a
single species of plants, which may be a grasses plant (such as English ryegrass)
or a leguminous plant (such as alfalfa).
These pastures have a limited life (1-4 years) and they are described as
temporary pastures.
Permanent pastures include several species of plants, both grasses and
leguminous, as well as shrubs (some may be regarded as weeds) and are
operational more than five years.
The feeding of the grazing animals is different from that of housed
livestock, for several reasons.
In the first place, intake is variable. A second important feature of the
grazing animals is that they lose more time and consume more energy in
harvesting plants from the pastures.
The diets of the grazing animals are therefore difficult to evaluate; even if
its nutritive values are known, the opportunities for correcting deficiencies are
limited.
Natural grasslands have a variable composition and nutritional values,
determined by a number of factors, including the stage of vegetation, botanical
family and others.

Stage of vegetation
The further advancing the plants in the vegetation, they accumulate large
amounts of crude fibre (CF), a wider extent from 20% in dry matter (DM) for
young plants to 40% in DM for mature plants.
Under these conditions, the digestibility of organic matter (dOM) varies
from 85% to young plants in spring to 50% for the same mature plants in autumn.
In a reverse situation with crude fibre is crude protein (CP), which
decreases as the plants advance in vegetation (in relation to dry matter content).
For example, on plain pastures, between the beginning and ending of
flowering, protein content decreases from 13% to 9% (in DM).
The advancement of plants from pasture in vegetation leads to an increase
in productivity, but a decrease in nutritional values and productive performances
obtained from animals.
 Some authors studied the cross-effects of vegetation stage and vegetation
cycle in a permanent pasture on the composition, nutritional values, consumption
and milk production in cows (along with pasture, provided ad libitum, cows
received and concentrates, offered restricted).
The floristic composition of the pasture consisted of 51% perennially
grasses, 21% perennially leguminous and 28% other plants. Three consecutive
cycles of vegetation were followed, each of seven weeks.
We present, in Table 1, extracts from the obtained results.
In terms of productivity, composition (protein content and crude fibre
content), nutritional values, consumption of cows and milk production, significant
interactions were found between the vegetation cycle and the vegetation stage (not
for the digestibility of the organic matter).

Botanical family
In connection with the botanical family, it has been shown that plants on
natural grasslands belong mainly to grasses and leguminous, plus other botanical
families (in smaller proportions).
It is recognized that quality pastures should contain: 65-75% grasses plants,
20-25% leguminous plants and 5-10% other species.
But the quality of pastures is given not only by the proportions of botanical
families, but also by representative species of each botanical family.
The species of grasses plants considered good quality are English ryegrass
and Italian ryegrass and among leguminous there are alfalfa, red clover and white
clover.
 Table 1 - The influence of the vegetation cycle and the vegetation stage of
permanent pasture on some experimental parameters in lactating cows

Vegetation week 1 3 5 7
The first cycle of vegetation
Productivity (kg DM / ha) 1692 3439 4842 5782
Crude protein (g/kg DM) 202 160 127 129
Crude fiber (g/kg DM) 222 283 315 326
Digestibility of OM SO (%) 78.2 72.6 68.5 60.8
Energy values (Mj NEL/kg DM) 6.44 5.89 5.48 4.78
Pasture consumption (kg DM/day) 13.34 12.86 12.32 10.66
Permitted pasture milk production
15.1 12.3 10.0 5.4
(kg/day)
The third cycle of vegetation
Productivity (kg DM / ha) 1968 3068 3625 3739
Crude protein (g/kg DM) 206 190 179 160
Crude fiber (g/kg DM) 272 273 274 268
Digestibility of OM SO (%) 78.0 74.6 70.7 67.7
Energy values (Mj NEL/kg DM) 6.31 6.00 5.65 5.30
Pasture consumption (kg DM/day) 12.80 13.03 13.01 12.02
Permitted pasture milk production
13.4 12.8 11.7 8.7
(kg/day)

Soil type can influence the composition of grasslands, especially mineral

content.
The structure and composition of the soil influences to a large extent the
content of grasses herbage in phosphorus, magnesium, copper and cobalt.
In normal conditions, plants react to the deficit of soil in minerals either by
limiting their growth or reducing their concentration in these nutritive elements.
Acid soils, with lower pH, is an important factor influencing sometimes
trace mineral elements in plant, especially molybdenum, while on calcareous soil,
manganese and cobalt are poorly absorbed by plants.
Fertilizing pastures can influence both the growth of the plants and content
of mineral elements. Using nitrogenous fertilizers leads to the increase of crude
protein in the plants, but also to the increase of the content of nitrates and amides
(the consequence is decreases the quality of the protein). In another way,
fertilizers with nitrogen stimulate the development of grasses on the detriment of
leguminous plants.
Operationally factors (especially overgrazing or under-grazing) lead to
disappearance of valuable plant species and the appearance of low-value species.
 Normally, after grazing the plants can have a better regeneration rate.

Green fodder crops

Green fodder crops are volume feeds which belong in particular to

leguminous and grasses plants, which can be added other plants species, but in
smaller share.

Green leguminous plants

This family of plants contains about 18000 species, which are recognized
by their ability to grow in a symbiotic relationship with nitrogen-fixing bacteria
and for their drought (dryness) resistance. Leguminous plants can be perennials
or annually.

Green perennials leguminous plants

Perennials leguminous are grown on large areas due to the high nutritional
values, high productivity and their use in diets for many species and categories of
animals.
First of all, they are excellent sources of protein, both in terms of quantity
and quality; this determines their administration alone to animals, leads to a waste
of protein, due mainly to the protein-energy imbalance.
That is the reason, it is recommended to administer perennials leguminous
in combination with feeds recognized by a lower protein content and a higher
energy concentration.

Alfalfa (Medicago sativa)

Alfalfa (lucerne) is a perennial leguminous plant which grows worldwide,

in a variety of climatic conditions, including Europe, United States, southern
Canada, Asia, southern Latin America, South Africa, and Middle East.
More than 35 million hectares of alfalfa are cultivated annually at global
level, making it the most important forage crop in the world.
Alfalfa is also called the "queen of forage crops" because of several
important advantages comparing to other sources of green fodders, like:
- very high yields;
- is maintained efficient in culture up to 4 years;
 - higher content of nutrients, particularly protein, calcium and carotene;
- better resist in drought conditions and responds well to irrigation;
- after alfalfa harvesting, land is richer in organic matter and nitrogen than
before; this means that after alfalfa other plants grow very well.
But alfalfa is sensitive to the type of soil (poor results on acid soils).
Unlike other leguminous, alfalfa is grown generally in monoculture (alone),
although it can be grown in mixture cultures, especially with perennials grasses.
These mixtures are more balanced nutritionally, but the productivity (kg DM/ha)
is lower than alfalfa grown alone.
Harvest time of alfalfa is very important, because maximum yield is not
obtained at the same time with maximum nutritional values.
Total dry matter (DM) obtained per hectare increases constant from the first
stage of vegetation to the early flowering stage, and then is maintained at the same
level up to the end of the flowering.
Digestibility of energy (dE) is highest in the first stage of vegetation and
decreases towards the end of vegetation. The same trend is recorded for crude
protein (CP) content.
Therefore, considering both goals (productivity and nutritional values), the
optimal harvest time of alfalfa is beginning of flowering.
The exception is only alfalfa in the first cutting, when the optimal harvest
time is half of flowering, allowing than a better regeneration.
Alfalfa can be administered to animals as green form (directly by grazing
or mowed), can be converted into hay and artificially dehydrated alfalfa or may
be turn into silage (with preservatives, because is part of the group plants with
difficult ensilaging, due to the higher buffering capacity).
Basically, alfalfa in its various forms can be given in diets for all animal
species and categories.
Alfalfa has a relatively low energy nutritional value (0.70-0.75 LFU/kg
DM) and high protein nutritional value (17-19% CP in DM).
It has very high calcium content, about 16 g/kg DM.
In ruminants, green alfalfa can cause ruminal bloat or tympany (gases
accumulation in the rumen), due to the saponins contained, which inhibit the
respiratory and digestive activities. The primary cause of ruminal bloat is the
retention of the fermentation gases in stable foam in the rumen, no longer
eliminated by eructation (by mouth).
To prevent a such situation is recommended that maximum consumption
of green alfalfa to be achieved gradually (in maximum 8-10 days), concomitant
addition in rations of dry forages (hays, straws), avoiding consumption of
moistened alfalfa (after rain, for example), fading alfalfa (partial drying) when is
administered in shelter.

Red clover (Trifolium pratense)

Red clover is a perennial leguminous adapted especially for northern

temperate zones of the world, such as Europe and North America. Worldwide is
cultivated around 20 million hectares, succeeded alfalfa in this respect.
Red clover gives better results than alfalfa in more humid regions and on
soils with lower pH (greater acidity). It is resistant to drought, but to a lesser extent
than alfalfa.
Effectively it resists in the culture shorter time than alfalfa, 2-3 years.
Red clover can be used in pure culture (alone) or in association with some
perennial grasses.
In animal diets can be used either fresh or turned into hay (with a risk of
drying more difficult) or into silage. Like alfalfa, green, red clover is difficult to
convert into silage, because of low dry matter content and low readily soluble
carbohydrates (high buffer capacity).
Ensiling red clover is better in association with perennials grasses, the
combination containing higher dry matter and high readily soluble carbohydrates.
In general, red clover can be used in animal diets with the same rules
presented for alfalfa (and red clover produces ruminal bloat).
In terms of nutritional values, it is observed significantly higher content in
energy than alfalfa (0.75-0.85 LFU/kg DM) and significantly less content in
protein (15-17% CP in DM). Some research has shown that, at the same crude
fibre content, red clover has higher digestibility than alfalfa (which also explains
the higher energy nutritional value), being better suited to the rations of high-
yielding lactating cows.
As vegetation progresses, the digestibility of red clover decreases, due to
increased lignin content and reduced rumen degradability of polysaccharides
other than starch.

White clover (Trifolium repens)

White clover, a Mediterranean plant, is the most important perennial

leguminous grown for grazing, especially in Western and Northern Europe, North
America, New Zealand and Australia.
 White clover culture is used increasingly more recently, due to better
adaptability than red clover, is more resistant to cold, recorded higher production,
get better in vegetation, has a greater resistance to defoliation when turning into
hay.
Although it can be used in pure culture, most often is used in combination
with perennials grasses to improve their nutritive protein value.
In the optimum harvesting stage, beginning of flowering, nutritional energy
value is very high among volume feeds (0.95-1.00 LFU/kg DM), otherwise
nutritional protein value (20-22% CP in DM).
The digestibility of white clover is higher than that of other perennials
leguminous grown in temperate areas. In addition, it has a higher degree of intake
and can be used more efficiently by animals.

Egyptian clover or Berseem (Trifolium alexandrinum)

Egyptian clover is an important leguminous plant grown in the

Mediterranean area, Middle East and India.
It is recognized for rapid growth in the cooler winter season in the
subtropics regions and for its good regeneration after cutting or grazing.
Nutritive values of Egyptian clover are very similar with those presented at
alfalfa.

Sweet clover (Melilotus albus)

Sweet clover is cultivated usually on sandy and salty soils, achieving better
results than other perennials leguminous plants. It is at the same time more
resistant to drought and frost, comparing to other plants of the same botanical
family.
It is recommended to be used as green fodder until to early bud stage,
because afterwards acquires a bitter taste and bad smell.
As in the case of other perennials leguminous plants, sweet clover has the
potential to cause tympany, but not to the same extent as alfalfa and red clover.
Sweet clover contains coumarin, which under certain conditions is
converted to dicoumarol.
Dicumarol is an anti-coagulant, which can cause internal bleeding, even the
death of the animals. Dicumarol is also considered antivitamin K.
In recent years new varieties of sweet clover were created, with lower
coumarin content.

Sainfoin (Onobrychis vicifolia)

 From this botanical family, sainfoin is a plant of less economic importance,
at least compared to alfalfa and red clover.
It is a perennial leguminous plant that works best on calcareous soils in dry
areas. Also, it goes better in vegetation than alfalfa and red clover in spring.
Sainfoin has lower crude protein content than alfalfa, especially after
flowering stage. It has a good level of minerals, but its calcium and sodium content
are lower than in other perennials leguminous. Also, sainfoin contains condensed
tannins.
Compared to alfalfa, red clover and white clover, green sainfoin does not
produce tympany, probably due to the ability of the tannins which it contains to
precipitate soluble proteins.
The addition of 10-20% sainfoin in green alfalfa-dominated rations reduces
the risk of appearance of tympany (tympanism) in fattening cattle.
In the same stage of vegetation, compared to alfalfa, sainfoin has higher
energy content and lower protein content.

Green annually leguminous plants

Annually leguminous plants are used on a smaller scale in herbivores diets,

comparing to perennials leguminous plants.
In pure culture annually leguminous plants can become sources of
nourishment only occasionally, not for their nutritional qualities, but for their
main destination is the production of grains. On a slightly larger scale are used in
mixed cultures, with annually grasses plants.
The most representative plant of this group is pea. Along with pea may be
listed: wetch, field bean, lupin and soya.

Pea (Pisum sativum)

Pea has a greater genetic diversity. The best known are garden pea
(consumed by humans, either green or grains) and forage pea (cultivated for
animals, consumed in green form or can be turned into silage or hay).
There are varieties of autumn and spring, varieties with leaf mass richer or
less, with vegetation periods shorter or longer.
Pea grows very well in cool climate and rainfall above average, on a variety
of soils. But heat and drought affect pea, especially during flowering.
For animals are cultivated varieties with leaf mass richer, ratio leaves/stems
higher, associated with higher nutritional value.
 Green pea can be cultivated in pure culture or mixed with some annually
grasses plants, like barley, oat, wheat or rye.
Growing in pure culture has the advantage of leaving the field early,
allowing sowing in the same year on the same land and other plants, so called
double crops (e.g., maize, sorghum).
Harvesting is between flowering and seeds formation, because afterwards
stems lignify and becomes hard consumable and hard digestible.
Growing with some annually grasses in mixed cultures has the advantage
of higher productivity, since annually grasses help pea not to fall to the ground.
Also, in this combination it has good energy-protein balance and it is better suited
for transformation into hay or silage.
In order to obtain the best productivity and the best nutritional values, there
must be certain ratios between pea and annually grasses, obviously if these are
grown together.
In terms of nutritional values, it can be observed a balancing between
energy and protein values.
In this regard, pea has about 0.80-0.90 LFU/kg DM and 16-17% CP in DM.
Pea also has a high content of calcium, close to that of alfalfa.

Wetch (Vicia sativa)

Wetch looks like pea, but with thinner and longer elongated leaves. It is
quite tolerant to cold and adapts to a diverse range of soils.
Like pea, wetch has a variety of autumn and spring.
It can be grown both alone, but most often in combination with the same
annually grasses, presented on pea.
Wetch if grown alone has a slightly shorter growing season than pea, so
that it can be used as a source of green mass even in late April and early May in
temperate regions. If grown in mixed cultures with annually grasses, wetch can
be harvested earlier if joins with rye, then with barley and then with wheat.
Energy and protein nutritional values of wetch are somewhat lower than
pea.
Wetch has a great ability to fix nitrogen from the soil. It can also provide
nitrogen to the plant which grown in association, as well as to future plants grown
on the same soil. It also has the ability to destroy weeds, especially when grown
in mixtures with annually grasses plants.

Field bean (Vicia faba)

 This plant is grown usually for seeds, but occasionally for green mass. As
green fodder, field bean is recommended to be administered to animals in smaller
quantities, or mixed with other green feeds, because it has a low degree of
consumption.
Field beans have two important varieties, which produces large grains
(especially for human consumption) and which produces small grains (used
primarily in animal feeding).
This plant does not require nitrogen fertilization, moreover, fixing
significant amounts of nitrogen in the soil and controls the occurrence of diseases.
Mixing field bean with annually grasses is good, maybe better than the
combination pea - annually grasses.

Lupin (Lupinus spp.)

Lupin has several forms, according to the colour of the flowers: white,
yellow and blue.
There are varieties "bitter" and "sweet“, differentiated by the content in
alkaloids and saponins (anti-nutritional factors).
Lupin for optimal growth needs cooler weather and it grows well on sandy
soils.
The protein content of lupin plants decreasing from 16% to 12% (in DM)
for all varieties, with the advancement in the vegetation, and under the same
conditions alkaloid content is reduced.

Soya (Glycine maxima)

Soya (soybean) is grown especially for grains. As green fodder is cultivated

on smaller scales, although it can be a very valuable forage resource. In order to
be cultivated as green fodder there are used different varieties than for grains, with
slower growth rate, with greater height, with more leaves.
Soya loves the heat and moisture, but it is sensitive if it grows on acid soils.
Harvesting as green fodder is recommended to be done at the beginning of
yellowing leaves, corresponding to the beginning of seeds formation. Regarding
protein content at this stage of the vegetation, soya is comparable with alfalfa.
Soya can also be grazed (by sheep and goats), as it happens in the USA.
The first grazing is recommended to be done when the plants have about 60 cm
high, corresponding to the best protein content.
Soya may be grown in inter-cropping with maize or sorghum. If it is
cultivated with maize, mixture can be transformed into silage, with 30-40% more
protein than maize. The association with maize also leads to increasing the intake
degree of soya.
Soya grown in inter-cropping with sorghum can be transformed into silage,
this combination (40% soya and 60% sorghum), especially with addition of
molasses, producing very good results, particularly in lactating cows.
 Course 2

Green grasses plants

Grasses are perennials or annually plants, like the leguminous plants presented so far.

Green perennials grasses plants

English ryegrass and Italian ryegrass are nowadays most cultivated perennials grasses.
Orchard grass, fescues, meadow grass and timothy are also cultivated, but on a smaller
scale.

English ryegrass (Lolium perenne)

English ryegrass is the most perennials grass cultivated in Europe and in other world
regions with temperate climate, thanks to its high productivity and its capacity to stabilize the
soil as well.
English ryegrass is a classic perennials grass, efficient operation lasting about 4 years.
Being adapted to the ocean climate, it is very sensitive to drought and high temperatures. More
resistant varieties have been created in semi-arid areas.
It is well suited to grazing (it resists to the pressure of the animals’ hooves, including
those of great size), which is the main way of operating. Moreover, English ryegrass is a tolerant
plant to frequent mowing.
English ryegrass requires fertilizers (including nitrogen fertilizers) and adapts well on
soils with different acidities.
It can be grown alone or in mixed cultures with other perennials grasses (such as orchard
grass or tall fescue) or perennials leguminous (white clover or alfalfa). Combinations (mixed
cultures) can be used in animal feeding, either fresh or processed into hays or into silages.
Transformation into hay is delicate due to the difficulties in drying, especially in the
case of steaming process. English ryegrass resists better to defoliation (loss of leaves) than other
perennials grasses when it is converted into hay. This effect is due to lower content in slightly
soluble carbohydrates, which is a positive fact.
English ryegrass has late varieties (with a longer vegetation period) and early varieties
(with a shorter vegetation period).
Before flowering, which is the optimal harvest time in good weather conditions (without
rain) the late varieties of English ryegrass have 0.80-0.85 LFU/kg DM energy value and the
protein value is about 8-9% CP in DM.
For early varieties, at the same stage of vegetation (before flowering), there are recorded
higher nutritional values, 0.90-0.95 LFU/kg DM and 11-12% CP in DM (INRA, 2010).
 English ryegrass is able alone to provide metabolisable energy and metabolisable
protein for lactating cows up to 30 kg/day milk production, if the animals consume enough food
to reach this productive level.

Italian ryegrass (Lolium multiflorum)

Together with English ryegrass, Italian ryegrass is currently the most cultivated
perennials grass (there is an annual form however), due to its high productivity and its high
nutritional values.
Perennials forms of Italian ryegrass are used with maximum efficiency for 2 years, then
it can be observed an obvious decreasing productivity, because some of the plants disappear.
Italian ryegrass has a fast growth and easy implantation in the soil (it is used successfully
as a first crop on empty land to prevent soil erosion). It is worth noticing a lower resistance to
cold and drought, because it is a plant of Mediterranean origin.
This perennials grass grown mostly alone, being a relatively tall plant (among perennials
grasses).
In terms of nutritional values, it is characterized by a balance between protein and
energy. The optimal harvesting phase, from nutritional values point of view, it is before
flowering.
For perennials varieties of Italian ryegrass before flowering, the energy values are 0.85-
0.90 LFU/kg DM and protein values are 10-11% CP in DM.
For annual varieties, the protein nutritive value is higher. In the same stage of vegetation
with perennials forms (before flowering) there can be reached even 18-19% CP in DM, like
alfalfa.
Italian ryegrass has a higher dry matter digestibility (due to higher percentage of cell
content, compared to cell walls) and a higher rumen protein degradability, compared to other
perennial grasses.
The degradability of the protein in the rumen is also higher in the green form than in the
silage form.
Italian ryegrass can be used as green fodder, silage or hay.

Orchard grass (Dactylis glomerata)

Orchard grass (cocksfoot) can be exploited long time, even 5-6 years. It is well adapted
to continentally tempered climate (like in Romania), resisting to drought quite well.
It is a valuable green fodder, especially before flowering (after that, it has a strong
tendency to lignification); it has good productivity and a great capacity for recovery after
grazing or mowing.
 Orchard grass can be grown alone or in mixtures with leguminous plants, especially
alfalfa, thus being able to be exploited either by grazing or by mowing. In good years and under
irrigation condition, it can be harvested 4-5 times per year.
Energy and protein values are similar with the ones presented at English ryegrass.
New varieties of orchard grass have been created, with longer periods of vegetation,
with a richer foliar mass, with higher productivity, with a higher resistance to diseases, with a
better adaptability in winter, with higher nutritional values.

Fescues (Festuca spp.)

There are two species of Fescue, meadow fescue and tall fescue.
Meadow fescue has good regeneration capacity, growing quickly after grazing or
mowing. It is considered one of the most resistant perennials grass (to drought, to cold, to excess
of moisture).
It can be operated both alone or in combination with white clover, by grazing and by
mowing.
Meadow fescue can be used in herbivores diets as green fodder or turned into hay and
silage (it is also an ornamental plant). Having a great easiness of implantation in the soil and
resisting for many years in culture, meadow fescue is used in the programs to combat soil
erosion.
Tall fescue is used mainly in mixtures with alfalfa, white clover or orchard grass for the
establishment of temporary grasslands.
It is one of the most heat-tolerant plants, but it is more sensitive in very cold winters and
to the insufficiency of water in the soil (in these conditions, its productivity and persistence are
obviously decreased).
Tall fescue can be infested with ergot, an alkaloid produced by some fungi, which can
affect animals, especially mares and cows in the last part of gestation (by abortions) and after
birth (by placental retention).

Meadow grass (Poa pratensis)

Meadow grass is a typical grassland plant which grows in all areas, from steppe to forest
regions.
It can be rarely mixt in order to establish temporary pastures, because it has a slow
growth rate and it is competed by other plants in the mixtures.

Timothy (Phleum pratense)

 Timothy is a perennial grass found frequently in the wild flora of the meadows in humid
regions. In these regions, mixtures of timothy with red clover are usually used for restoring
degraded grasslands.
Productivity (kg DM/ha) of timothy increases as vegetation progresses, but digestibility
decreases, perhaps more than in other perennial grasses, because it has a higher proportion of
stems compared to leaves.
The protein from timothy is degraded to a greater extent in the rumen, which means a
lower rate of using nitrogen by ruminants. Nitrogen fertilization, apart from increasing
productivity, has no notable effects on digestibility.

Green annual grasses plants

Along with maize (corn), the typical plant of this group, the annual grasses also include
sorghum, barley, oat, rye, wheat, etc.

Maize (Zea mais)

In the last 30-40 years, green maize and maize silage produced a profound shift in the
ruminant’s feeding. Worldwide, maize used as green fodder or silage occupies an area of 17
million hectares, and the EU is the first cultivator (about 6 million hectares).
Optimal growing conditions include average daily temperatures of 18-21° C (too low
temperatures affect plants development), optimal rainfall (especially during flowering), and
avoidance of excess of moisture in the soil. As green fodder, maize has a very variable
productivity, from 10 to 40 tons DM/ha (30-40 tons DM/ha is a very high productivity).
Unfortunately, maize is easily attacked by diseases and pests. Herbicides, pesticides and
fungicides should therefore be used.
At present there are varieties of genetically modified maize that do not require the use
of herbicides and pesticides, with a positive impact on the environment, but controversial at
least theoretically, for modifying the DNA of soil micro-organisms and useful insects, such as
bees.
Maize varieties used as green fodder or silage are different than those grown for grains,
with greater height, with richer foliage mass.
Optimal stage of harvesting depends on the modality of use.
Thus, if it is used as the green fodder, harvesting is recommended between the flowering
stage and grain milk stage (whole plant has 20-25% DM), and if it is turned into the silage, it is
recommended to be harvested in grain milk-wax stage or in grain wax stage (30-35% DM at
the whole plant level).
Lately, there are more and more discussions about harvesting maize in an earlier
vegetation phase, before flowering. For this, special hybrids can be used, that have a vegetation
period of only 55-60 days between sowing and harvesting. Because maize is harvested in very
young stage, it has a very good quality, with a high degree of consumption and digestibility.
Forage maize whole plant is rich in starch and simple sugars but poor in protein and
minerals. Compared to other forages, the digestibility of maize is very high and constant,
regardless of the state of vegetation (obviously as long as it remains in the green stage).
These features give a very high energy value for a volume feed: 0.88-0.90 LFU/kg DM,
close of the concentrates. However, protein value is lower (7.5-8% CP in DM).
Between the grain milk stage and the grain wax stage, the protein content of the leaves
decreases significantly from 13.5% to 8.5%, while the protein level in the stems and grains
remains at a relative constant level.
The composition, nutritional values and productive effects of green maize whole plant
are also dependent on the variety and the genetic type. There is a difference in the milk
production of cows up to 2 kg/day, between varieties with a lower degree of digestibility and
those with a higher degree of digestibility.
Due to energy-protein imbalance, maize is better to be associated in rations with
leguminous plants or other complementary feeds.

Sorghum (Sorghum spp.)

Sorghum has two varieties: fodder sorghum (Sorghum vulgare) and Sudan grass
(Sorghum sudanense).
These two varieties of sorghum can provide green mass in dry regions (their resistance
to drought is superior rather than maize, due to a more developed root system). Sorghum resists
well even on salty soils.
All these properties make sorghum an important crop in arid and semi-arid regions of
the world. However, it is sensitive to cold and high humidity in the soil.
It can be grazed in earlier stages of vegetation (at maturity it becomes a large plant, over
2 meters), it can be mowed or turned into silage or hay.
In the early stages of vegetation (40-50 cm height) sorghum has pronounced toxic
effects due to cyanogenic glycosides contained. Therefore, in these earlier stages of vegetation,
it is recommended to be administered to adult animals (more resistant), in limited quantities or
to be transformed into silage.
As the vegetation stage progresses, both the nutritional values and the degree of
consumption decrease rapidly (which is not recorded in maize).
At the same dry matter content (until flowering) sorghum has a slightly lower energy
nutritional value than maize and a similar protein nutritional value.

Barley (Hordeum vulgare)

 Barley is grown mainly for grains but is also a valuable green fodder (mowed or grazed),
silage or hay.
It is a plant that reaches up to 1.2 m in height, with a ratio leaves/stem relatively tall. It
is the most tolerant to saline soils annually grasses.
There is a large variety of barley, differentiated by many criteria, including sowing time
(autumn, spring).
Barley can grow both in pure culture and in mixed cultures with some annual
leguminous (e.g., pea).
The mixed culture has greater resistance to diseases, eliminates weeds, have a higher
productivity than barley cultivated separately.
In low humidity conditions, barley can be sown in early autumn and in high humidity
conditions, it can be sown in mid-autumn, obviously if there are autumn varieties.
In the case of spring varieties, barley should be sown as soon as possible. These
specifications were made because are compatible with the best productivity, up to 8-10 tons
DM/ha.

Oat (Avena sativa)

Like other annually grasses, oat is cultivated for grains and also for green fodder
(possibly transformed into silage or hay). Compared to barley, it is better adapted to lower
temperatures and it is more resistant to drought. Oat can grow on different soils, including the
one more acidic and less fertilized.
Like barley, oat can grow alone, in pure culture, or in combination with annual
leguminous. The mixture of oat and vetch is used with good results.
Oat is competitive against diseases and requires fewer herbicides. Also, oat needs less
fertilizers, including nitrogen fertilizers.
Optimal harvesting time of oat (as green fodder) is when the whole plant has about 28-
30% DM (or grains about 65% DM).
Oat, like barley, has autumn and spring varieties. Varieties sown in spring have higher
productivity, but slightly lower nutritional values.
Whole plant green oat has a great variability in composition, depending on the stage of
maturity, climatic conditions and other reasons. The protein content ranges between 6.3% and
12% (in DM), slightly lower than that of barley and wheat, at the same stage of maturity.

Rye (Secale cereale)

Rye is used mainly for grains, but also as green fodder, later form possible to be ensiled
or turn into hay. Transformation into hay is more difficult because the plants have high water
content at the optimal harvesting time.
 Having a shorter vegetation period, after rye harvesting as green fodder, on the same
land and in the same year, another crop can be sown, such as maize or sorghum.
Because it is tolerant to lower temperatures, to insufficient soil moisture and to acidic
soils, rye can replace wheat (poorer results in such conditions).
Rye is recommended to be mowed before flowering (faster than other plants), because
after that it lignifies strongly, it becomes harder to be consumed and its nutritional values
decrease.
In large quantities, at the beginning of the green season and especially when
administered wet, rye can induce digestive disorders; because of this fact, it is recommended
the gradual transition to the maximum allowed consumption, adding in rations hay or straw,
etc.

Wheat (Triticum spp.)

No doubt, wheat is grown especially for grains. However, it can be cultivated for green
mass, which can then be converted into silage or hay.
Wheat has autumn varieties and spring varieties (depending on the time of sowing).
Autumn varieties are indicated in regions with temperate climate, while spring varieties
are recommended in tropical or subtropical regions.
Wheat productivity, as green fodder, is very variable. In the USA, the average wheat
production, used as volume fodder in herbivore rations is on average 3 tons DM/ha, but 10 tons
DM/ha were also obtained.
Significant amounts of herbicides, pesticides, nitrogen or potassium fertilizers, with
possible implications for soil or water contamination, are needed to achieve higher productivity
for wheat.

Silages

Silages are volume feeds produced by the controlled fermentation of green crops (with
high moisture content).
Ensiling is a manner for preserving green feeds, to manage their use for a longer time
in herbivores diets. Ensiling involves harvesting green plants in field, transport in farm,
chopping, compaction and envelopment.
With these conditions met, in the mass plants subject for ensiling take place many
transformations, with different origins.
Knowledge of these changes, transformations allow taking measures to improve silage
quality.

Transformations that take place in silages

 In silages many transformations take place, thanks to the development of biochemical,
bacterial and fungal processes.
Without a clear delimitation, activities taking place in silages, from the beginning to the
end of the ensiling process, can be classified as:
* enzymatically activity
* bacterial activity
* fungal activity

Enzymatically activity (pre-fermentative phase)

Green plants mowed, subject to ensiling, continue to live and breathe several days, as
long as they have oxygen and remain in a wet environment.
The hydrolysis reactions are the first reactions that appear in the plants subjected to
ensiling, and they refer primarily to the reserve carbohydrates, especially starch. But, simple
sugars (glucose, fructose) are hydrolyzed, according to the classical relation:

(C6 H12 O6)*n + n*O2 = n*CO2 + n*H2O + heat

The proteolysis reactions occur then. This means that the cleavage of the proteins into
peptides occurs, then peptides into amino acids (AAs). The latter (AAs) are deaminated, with
the production of ammonia (NH3).
In these circumstances, the cell membranes are altered, and it is released the cellular
juice.

Bacterial activity (fermentative phase)

On the background of the previous transformations (hydrolysis and proteolysis

reactions), micro-organisms present on the plants begin to proliferate and action, using the
content of the cells (cellular juice) as nutrients substrate.
Behind micro-organisms activity result some fermentations, the best-known being:
acetic fermentation, lactic fermentation, butyric fermentation, and alcoholic fermentation.
Acetic fermentation
Acetic fermentation is caused by acid bacteria. Acid bacteria act first on the plants
intended for ensiling, because they are facultative aerobic. Their activity is exerted on soluble
carbohydrates, generating acetic acid (which causes the beginning of acidification), alcohol and
carbon dioxide.
Acid bacteria also degrades the proteins, transforming them into NH 3 (the consequence
is the reduction of protein nutritive value).
Therefore, lifetime of these bacteria should be limited as much as possible.
 Quality silage will have low amounts of acetic acid, about 2-3% in the silage dry matter.
Lactic fermentation
Progressive acidification of silage mass favors the multiplication of lactic bacteria,
especially if these have an anaerobic environment.
Lactic bacteria will develop more if the conditions are more favorable: anaerobic
environment, proper temperature, sufficient simple sugars, and pH below 6. If all these
conditions are met, the development of lactic acid bacteria will be exponential and will cause
strong environmental acidification (pH below 4), blocking the development of other species of
micro-organisms and stabilization of the silage.
There is a large number of lactic acid bacteria species, which are usually classified into:
homo-fermentative bacteria and hetero-fermentative bacteria.
Homo-fermentative bacteria breaks down soluble sugars (glucose, fructose) with the
almost unique production, lactic acid, with high efficiency (about 90%).
Also, these bacteria are capable to reduce nitrates into nitrites, and then into NH3.
Hetero-fermentative bacteria produce, on the same nutritive substrate, less lactic acid
(with a lower efficacy, less than 45%), and acetic acid, ethanol, hydrogen, etc.
Under optimal conditions, the lactic acid reaches to 4% of the dry matter of silage in 5
days and stabilizes at 6-7% in the DM in less than two months. Normally, lactic acid must have
at least 65-70% of the total acids occurring in silage mass.
Butyric fermentation
Butyric bacteria attacks both soluble sugars and lactic acid (with the production of
butyric acid and gases) and proteins (with the production of NH 3 and amines).
Butyric bacteria spores, present in silage, germinate if there is enough moisture and
nutrient substrates (sugars, AAs).
The consequences that appear are the loss of nutritive value (deamination or
decarboxylation of AAs), increased pH, and organoleptic and sanitary deterioration of the
silage.
Too much butyric acid obviously determines the intake drop of silages by animals.
Butyric bacteria are strictly anaerobic, and their maximum development occurs at a pH
value of 7- 7.4. At a pH level of 4-4.5, the activity of butyric bacteria is inhibited.
Alcoholic fermentation
Alcoholic fermentation is produced by yeasts, such as Saccharomyces cerevisae. These
micro-organisms consume oxygen and so, they favor the development of lactic bacteria.
Behind alcoholic fermentation, with small share in the total fermentations, it results
mainly ethanol, which gives the silage a pleasant taste and smell.
A high quantity of ethanol, 3-4% in the DM, shows an excessive activity of yeasts and
can affect the smell of the milk, although a part is converted into acetic acid in the rumen.
 In conclusion, during the fermentative phase, lactic fermentation must be a priority,
acetic fermentation must be limited and butyric fermentation must be controlled.
We present in connection with this aspect, in Table 27, the ideal fermentation profile
for three silages (maize silage, perennially leguminous silage and perennially grass silage), with
important share in herbivores rations.

Table 27 - The ideal profile of fermentations in several silages

Specification Perennially
Perennially
Maize silage leguminous
grass silage
(30-40% DM) silage (30-40%
(30-35% DM)
DM)
pH 3.7-4.2 4.3-4.7 4.3-4.7
Lactic acid (% in DM) 4-7 7-8 6-10
Acetic acid (% in DM) 1-3 2-3 1-3
Propionic acid (% in DM) < 0.1 < 0.5 < 0.1
Butyric (% in DM) 0 < 0.5 0.5-1
Ethanol (% in DM) 1-3 0.2-1 0.5-1
Ammoniacal N (% in DM) 5-7 10-15 8-12

Fungal activity (post-fermentative phase)

There is also a post-fermentation stage in silage, by the proliferation of several species

of molds and yeasts. Molds (such as Fusarium) are strictly aerobic, so if compaction is done
efficiently in silage, they do not develop.
Yeasts (such as Saccharomyces) present on the plants in the sporulated form, are not
active in the post-fermentation phase. They can become active only if there are properly soluble
sugars (such as glucose). But another yeast (Candida) can be developed if there is oxygen (is
tolerant to the pH of the silage) that attacks nutrient substrates, particularly organic acids (lactic
acid i.e.), creating finally instability in silage.

Factors influencing silage quality

From all the many factors that influence the quality of silages, there will be presented
only: soluble sugars content of plants, plants dry matter content, chopping + compaction +
envelopment of silages and use of silage additives.

Soluble sugars content of the plants

 The desired fermentations install easier and more deeply, as subject silage plants contain
a higher number of soluble sugars.
If the slightly soluble sugars content is lesser (under 2.5%) in the plants which are
subject to ensiling, then these must be partially dried before.
The main slightly soluble carbohydrates are glucose, fructose and sucrose. Most lactic
bacteria cannot ferment starch, but a part of it is hydrolyzed by amylase.
Grasses (mainly maize), with a higher content in soluble sugars, they can be ensiled
easier than leguminous plants (alfalfa first).
However, the content in soluble carbohydrates is affected, in addition to the species of
plants, by other factors: stage of vegetation (higher in young plants), cycle of vegetation (greater
in cycle one), climatic conditions (higher in cold springs) or fertilizer degree (higher than use
smaller quantities of nitrogen fertilizers).
All plants contain certain compounds, called "buffers", which resist to pH changes.
These neutralize organic acids from the silages, restrict the acidification, and thus creating
conditions for the development of unwanted bacteria. Between the content of plants in soluble
carbohydrates and "buffer capacity" there is an inverse proportionality relationship.
We present, further, in Table 28, the content of several plants subjected to ensiling in
slightly soluble sugars and their buffering capacity.
Table 28 - Soluble sugar content and buffer capacity in some silages

Soluble sugars Buffering capacity

(g/kg DM) (g lactic acid/kg DM)
Specification
Mean Mean
Limits Limits
values values
Maize 250 150-350 35 25-45
Oat 150 100-300 45 35-60
Rye 130 70-200 55 30-75
Perennially
110 60-290 50 30-75
grasses
Red clover 100 40-130 70 55-85
Alfalfa 50 30-80 80 70-95

Source: Knabe et al. (1986), read by Podkowska and Potanski (1991)

Plants dry matter content

Content of the plants in dry matter has a considerable importance on the course of
fermentations in the silages.
 This is because the excess water (low dry matter), and at the same time water-soluble
compounds (carbohydrates, proteins, minerals, fermentation products) will get to the base of
the silage, recording losses of nutrients (the environment is also affected by their
decomposition).
When the plants have lower dry matter content, acetic fermentation is stimulated and
decreases quality of the silage.
At a higher concentration of dry matter (and therefore less water), the compaction of
silages is inefficient (not provided anaerobic conditions) and undesirable fermentations is
stimulated.
In these conditions, the plants subjected to be transformed into silage should have
between 25 and 45% dry matter content (25-35% for un-wilted silage and 35-45% for wilted
silage).

Chopping, compaction and envelopment of the silages

Chopping of plants determines quick release of cellular juice (nutritional substrate of

lactic acid bacteria) and proper compaction (creating anaerobic environment) and leads to
increasing consumption of silage by animals. For maize, chopping is made to smaller
dimensions (1-1.5 cm) than for other plants (2-3 cm).
The compaction must be made immediately to create a strong anaerobic environment,
favourable to the development of lactic acid bacteria.
Envelopment is made using plastic sheets, immediately after compaction.

Adding silage additives

Silage additives can be divided into:

- stimulators of fermentations
- inhibitors of fermentations

Stimulators of fermentations
There are many stimulants of fermentation, such as: some feeds, enzymes and
inoculants.
Some feeds, such as molasses or cereals, are incorporated in silages to favorably
influence fermentation processes and thus silage nutritional values.
Adding molasses provides soluble sugars, which will be used by lactic acid bacteria to
produce lactic acid. Molasses contains within the dry matter, a very large amount of water-
soluble carbohydrates (83-85%), especially sucrose.
Due to high viscosity (1 liter = 1.4 kg), molasses is diluted with water in equal parts
(1/1), in order to be incorporated into the mass of plants subjected to ensiling.
 Cereals, in ground form, such as barley or oat, are incorporated into silages and for their
contribution to soluble sugars and for their absorbent power (an important fact for silages with
high humidity).
Enzymes, like celulases and hemi-celulases are placed into silages to break the bonds
of complex carbohydrates.
There are several commercial preparations containing such enzymes, which can be used
alone or in a mixture with inoculants.
With the development of biotechnology, the efficiency of the use of enzymes in silages
has improved and the costs have become lower.
Inoculants are homo-fermentative bacteria (Lactobacillus plantarum, L. pediococcus,
L. buchneri) which improve quality fermentation, by decreasing the pH, increasing the share of
lactic acid and the lactic acid / acetic acid ratio and by decreasing the ammoniacal nitrogen in
silages.
Inhibitors of fermentations
Acids and salts of organic acids produce an imminent drop in pH, thus preventing the
development of undesirable micro-organisms.
The problem of acids is their "aggressivity" towards humans who handle them, attacking
the eyes and skin. In addition, formic acid is volatile and it can get into respiratory tract.
Salts of organic acids, such as those of propionic acid or acetic acid, do not have such
effects, but to be effective they must be used in large amounts.
 Hays, artificially dried forages, straws

After green fodders and silages, other volume feeds are hays, artificially dried forages
and straws, with the indication that artificially dried forages can also be considered as
concentrate feeds.

Hays

The traditional method of conserving green plants is haymaking.

The aim in haymaking is to reduce the water content of the green plants to a low level,
enough to inhibit development of micro-organisms, from 65-85% to 15-17%.
During drying plants to be turned into hays, inevitable losses occur, leading to reduction
of their nutritional values.

Losses during drying green plants

The losses of nutrients during haymaking are due to several causes: chemical processes,
micro-organisms action, mechanically handling and storage.
Chemical losses
Chemical losses appear during the drying process, and they refer to soluble
carbohydrates and nitrogenous components.
In the early stages of the drying process, some water-soluble carbohydrates are affected,
such as formation of fructose from the hydrolysis of fructans.
During extended periods of drying, a considerable quantity of glucose is lost, as a result
of respiration, and this leads to an increase of the concentration of other constituents in the
plants, especially the cell walls components (crude fiber).
In the freshly cut plants, proteases present in the cells, rapidly hydrolyse the proteins
into peptides and peptides into amino acids, being followed by some degradation of specific
amino acids.
Losses due to the action of micro-organisms
If drying is prolonged, because of bad weather conditions (especially the rain), then
other changes occur, due to the activity of bacteria and moulds.
Bacterial fermentation takes place in cut herbage and leads to the production of small
quantities of acetic acid and propionic acid.
Mouldy hays are unpalatable and may be harmful to farm animals and humans who
manipulate them, because of the presence of mycotoxins.
Such mouldy hays are responsible for an allergic disease affecting humans, known as
‘farmer’s lung’.
 Mechanically losses
During the drying process, the leaves of plants lose water more rapidly than the stems,
so they become brittle (fragile) and easily broken by handling.
Excessive mechanically handling causes a loss of this leafy material, and since the
leaves are richer in digestible nutrients than the stems, the result is producing hays with low
nutritive values.
Leaves are lost during haymaking especially in the case of leguminous plants, such as
lucerne or clover.
Losses during storage
The stored hays contain 15-17% moisture (water), on average. At the higher moisture
levels of stored hays, chemical changes determine the action of plant enzymes and micro-
organisms, leading to loss of nutritional values.
Overall losses
The overall losses during haymaking (the sum of those presented above) can be
appreciable under poor production conditions of hays.
Losses of nutrients, measured between harvesting plants that will be transformed into
hay and animal’s feeding, are about 20% for dry matter (15% field losses and 5% storage
losses). The losses of digestible organic matter and digestible crude protein are about 25%.

Types of hays

Hay may be originated from natural pastures or cultivated plants.

Natural hays are characterized by a high variability of their characteristics, given by the
climatic conditions that influence plants growth and quality.
Hays obtained from cultivated plants belong most often to perennially leguminous
family and perennially grasses family but can also be produced from annually leguminous or
from annually grasses plants.
A valuable hay is a combination between annually grasses and annually leguminous.
In the following will be presented the main types of hays derived from cultivated plants.

Perennially leguminous hays

Alfalfa hay is the most used and the most valuable, leading to its characteristics: high
productivity, high nutritional values, it can be administered in diets for all animal species and
categories (including monogastric animals, in the form of alfalfa flour pelleted).
In normal conditions of animal husbandry, cannot miss in the winter rations of
herbivores, especially breeding males, young animals, pregnant and lactating animals.
 In the case of breeding males and pregnant females belonging to herbivores positively
influences digestive processes and implicitly health, in youth favorably influence growth, in
lactating females stimulate milk production and increase milk fat content.
Given that silages (especially maize silage) are increasingly used in herbivores diets,
these find a perfect complement in alfalfa hay (for balancing energy-protein in the diets and
rumen fermentation processes).
Alfalfa hay contains about 25-30% non-structural carbohydrates quickly digestible in
the DM (like pectic substances, simple sugars or starch) and about 35-40% structural
carbohydrates in the DM (cellulose, hemi-cellulose, and lignin) more difficult to digest.
Crude protein content is high among volume feeds, between 16% and 22% in the DM.
Of the whole crude protein, 25-35% is rumen non-degradable protein, which is important for
ruminants, especially for lactating dairy cows with high milk yields.
Alfalfa hay in flowering stage of vegetation has about 0.65-0.70 LFU/kg DM and about
16-18% CP in dry matter.
Other perennially leguminous hays have the same characteristics as alfalfa hay,
generally. These can replace alfalfa hay in the areas where this plant produces lower results in
terms of productivity.
Among other perennially leguminous hays, without alfalfa hay, are worth remembering:
red clover hay (in humid climate and more acidic soils), sainfoin hay (on calcareous soils and
in dry areas), and sweet clover hay (on sandy and salty soils).
When red clover hay is produced, green plants should be harvested at half-flowering
stage, which corresponds to the optimal nutritional values. At a more advanced stage of
vegetation, productivity is affected and the next mowing is compromised.

Perennially grasses hays

From this botanical family, Italian ryegrass and English ryegrass are most often turned
into hay.
In terms of nutritional values, compared with alfalfa hay, perennially grasses hays have
slightly higher energy value (about 0.70-0.75 LFU/kg DM) and obviously lower protein
content, 10-12% CP in DM (INRA, 2010).

Annually leguminous and grasses hays

Such hays are produced on a small scale, but there are potential sources in animal diets.
Soybean hay is an example, as annually leguminous, which can be produced if grain
production is compromised. However, soybean hay can also be produced under normal
conditions, constituting a valuable feed, especially if it is harvested between flowering and the
beginning of grains formation.
 If the green soybean turns into hay (when the grains are formed) it contains a large
amount of fat, which induces a decrease in appetite and digestive disorders can occur.
Of the annually grasses, oat often turn into hay, but other annually grasses may follow
the same path.
Mowing oat plants which will be transformed to hay (in the grain milk stage) is the best
compromise between productivity and nutritional values.
By using higher density at sowing (up to 80 kg seeds/hectare) occurs an improvement
of the quality of oat hay, because decrease the stiffness (rigidity) of the stems.

Artificially dried forages

The process of artificially drying is a method of conserving green forage crops, which
produces high quality feeds. Artificially dehydration was found to be the best way to stabilize,
to preserving green plants, its protein content, vitamins and overall nutritive values.
In northern Europe grasses and grasses-clover mixtures are the most common crops
dried by this method, whereas in North America alfalfa (lucerne) is the primary crop that is
dehydrated.
The drying is realizing by passing the green plants rapidly through a rotating drum
(tambour), where meets hot gases at a temperature of about 800° C. The temperature and time
of drying are controlled very carefully, so that the forages are never completely desiccated, and
the final product usually contains about 5-10% water.
After drying, the product obtained is generally milled (but not to small sizes, as is the
case of some concentrate feeds) and passed through a rotary press to form pellets.
As a conservation technique, artificially drying is extremely efficient. Dry matter losses
from mechanically handling and drying itself are together unlikely to exceed 10%, and the
nutritive values of the dried product is therefore close to that of the fresh crops, of course by
reference to DM.

The most known artificially dehydrated green fodder is alfalfa. Under this dry form,
alfalfa has a very high protein content, high vitamins, xanthophylls and beta-carotene levels,
making usable in all animal species, even in poultry and pigs.

Straws

Straws consist of the stems and leaves of mature plants after the removal of the seeds
by threshing, and are produced from the most cereal crops and from some leguminous crops.
 In arid climate, the straws are important sources of feeds for herbivorous animals. In
temperate areas, straws are often used in animal feeding in emergency situations, such as
drought.
All the straws are extremely fibrous (over 40% crude fiber), most have a high content
of lignin, and all have low nutritive values. Their high crude fiber content restricts the use only
for ruminants and horses.
In order to improve nutritional values, straws can be subjected to treatments, chemical
or biological.
Chemical treatments are intended to break the links between lignin and cellulose and
fragmentation of the latter in smaller chains, to improve digestibility. The most common
chemical treatments are made with sodium hydroxide, hydrochloric acid, ammonia and urea.
The use of such substances, beyond being difficult to handle, can induce animal health
problems if are administered in large quantities.
Biological treatments, with fungas or enzymes, are the same purpose, to break lingo-
cellulosic bonds. The use of fungi, such as Aspergillus or Trichoderma, has led to improve
nutritional values of wheat and rice straws.
Biological treatments of cellulosic feeds have the chance to be used more widely in the
future, because they are environmentally friendly.
For the beginning, the types of straws from cereal crops will be presented, then those
from leguminous plants.
Barley and oat straws
The major component of the barley and oat straws is the crude fiber (40-45%), which
contains a relatively high proportion of lignin (8-12%).
For such feeds (like barley and oat straws, except maize straw), the composition usually
refers to their natural form (as basis), and less to their dry matter (dry matter basis), because
they have more than 90% DM, and the differences between the two ways of expression are very
small.
The crude protein content of both straws is low, usually in the range of 3-5%, with the
higher values obtained in such crops grown under cold and wet conditions, where they do not
fully reach maturity, complete lignification.
Virtually vitamins and minerals content of barley and oat straws do not matter, as well
as for other straws.
Digestibility of organic matter does not exceed 50%, and the energy nutritive value is
about 0.45 LFU/kg.
Apart from the low digestibility and nutritive values of these cereal straws, a major
disadvantage is the low intake obtained when they are given to herbivores animals.
 Improvements both digestibility and intake can be obtained by chemical and biological
treatments. By treatment with anhydrous ammonia, the energy value of straws increases to
about 0.6 LFU/kg and the protein nutritional value even by 2.5 times.
Wheat and rye straws
Wheat and rye straws have a lower energy nutritional value than barley and oat straws
and a similar protein nutritional value. Cell-walls content (NDF) is similar, and non-structural
carbohydrates (NSC) content is lower than in barley and oat straws.
As other straws, the nutritional values of wheat and rye straws can be improved by
chemical and biological treatments.
For example, treatment with anhydrous ammonia of wheat straw led to an increase in
their crude protein content by 65-100%. The efficiency of microbial protein synthesis in the
rumen has also increased, as well as the total non-ammoniacal nitrogen that reaches in the
duodenum.
Rice straw
In many of the intensive rice-growing areas of the world, particularly Asia, this straw is
used as a feed source for farm animals.
Its protein content and energy values are similar to those of spring barley straw.
It has exceptionally high ash content, about 17%, which consists mainly of silica. In
contrast to other straws, the stems are more digestible than the leaves.
Rice straw can be subjected to treatments (mechanical, chemical) to improve nutritional
values. Urea treatment is easier to be applied than other chemical treatments and it has led to
an increase in rice straw digestibility by 18%.
Table 30 shows few nutritional values for the straws of some cereals crops, by reference
to the dry matter (DM) content, namely: crude protein (CP), ether extract (EE), neutral detergent
fiber (NDF), non-structural carbohydrates (NSC) and net energy for lactation (NEL).

Table 30 - Nutritional values of wheat straw compared to oat and barley straws

CP EE NDF NSC NEL

DM
Specification (% in (% in (% in (% in (kcal/kg
(%)
DM) DM) DM) DM) DM)
Wheat straw 93.6 4.6 1.6 78.8 9.7 790
Oat straw 93.3 4.8 2.1 77.0 9.7 925
Barley straw 93.1 4.4 2.0 77.3 11.5 860
 Maize straw
Maize straws are the stem with leaves and they result as a by-product from the picking
of the maize cobs. Maize straw, or corn stover, has higher nutrients content and is more
digestible than most other straws.
Maize straw has a crude protein content of about 6% in DM and energy value about 0.6
LFU/kg DM.
It is possible that, during the harvesting cobs with grains, the maize straw to have higher
water content than other types of straws. That is why, it is preferable to express the composition
and nutritional values of maize straw per kg dry matter.
Leguminous straws
The straws of pea and soybean have higher nutritional values than cereal straws.
Pea straw has a protein content over than 7% CP in DM, a content in energy higher than
cereal straws, despite the fact that digestibility is about the same.
Pea straw can be used both as a source of animal nourishment (especially for sheep) and
as organic fertilizer incorporated into the soil.
Soybean straw has a low degree of palatability due to the hardness of the stems, which
is why they are used in limited amounts in ruminant rations.
Because of their thick (gross) stems, soybean straw is more difficult to be dried than
cereal straws and frequently become mouldy during storage.
However, in the areas where soybean is grown for grains, soybean straw is not a
negligible source for ruminants feeding.
 Roots, tubers and related by-products

Roots
The main features of roots, in terms of composition, are high water content (75-90%)
and low content in crude protein and crude fibre.
Root’s dry matter is dominated by carbohydrates (50-75%), especially readily soluble
carbohydrates (glucose and sucrose).
The main roots are the following: beet, carrots, kale, and turnips.

Beet (Beta vulgaris)

The traditionally varieties of beet have multigerm seeds, which means that the plants
are separated after coming out of the ground.
With the emergence of monogerm varieties in the 1970s, and almost complete
mechanization, the cultivation of beet has become increasingly important.
There are several varieties of beet, differentiated by dry matter (DM) content, between
10% DM and 22% DM. Broadly speaking, those with a lower content in dry matter belong of
fodder beet, and those with a higher dry matter content belong of sugar beet.
The main destination of fodder beet is the ruminant animals, but it can be also used in
diets of rabbits or pigs, that are traditionally raised.
Fodder beet is widely used in feeding lactating cows. But, in a too large quantity, it can
cause digestive disorders (associated with high sugar content) and hypocalcaemia. It is therefore
advisable to be associated in rations fodder beet with fibrous feeds (hays, straws).
Organic matter digestibility is very high, about 90%, and energy nutritive value along
the same lines, about 1.15 LFU/kg DM.
The use of fodder beet in pig’s diets has satisfactory results. However, fodder beet is
recommended to be given raw to pigs, because if it is boiled, poisoning can occur, by
transforming the nitrates contained into nitrites.
Sugar beet is used in the sugar industry, as the main destination. But it can be used in
animal feeding, especially in lactating cows’ diets. For the same reasons presented in fodder
beet, sugar beet should be given restricted in ruminants’ diets.
Beet (fodder beet, sugar beet) is one of the crops that consume large amounts of carbon
dioxide and releases large amounts of oxygen into the atmosphere.
Genetically modified varieties of beet have been created, but they are banned in the
European Union since 2011.
 Carrots (Daucus carota)

Carrots are used in animal feeding usually fresh. But they can be also used in dehydrated
form, (especially for pets and horses) or as silage (with straws and milled cereals).
Carrots have high water content (85-90%), high digestible organic matter (about 85%)
and about 10% crude protein in dry matter. With such features, carrots have a high energy
nutritive value, about 90% of the maize grain, with reference to the dry matter.
Also, carrots have a high content in beta-carotene. Studies on lactating cows have shown
that the use of carrots in their rations led to an increase of vitamin A in milk, and the butter
obtained has a specific color.
Due to limited quantities, carrots are recommended primarily in winter rations of
convalescence herbivores and breeding males belonging to herbivores.

Kale (Brassica rapa)

Kale can be used equally in human nourishment (varieties with smaller roots) and
animal feeding.
The water content of kale is high, but by reference to the dry matter has a high energy
nutritive value (close to barley grains) and good protein nutritive value.
Kale is not recommended to administer in lactating cows diets a few hours before
milking, because it may affect milk quality (taste and smell).

Turnips

Yellow turnip (Brassica napus) or Rutabaga and white turnip (Brassica campestris)
are chemically very similar and are grown for human consumption or as feeds for livestock.
Both are liable to taint milk quality if they are given to dairy cows before milking time.

Tubers

Potato tubers (Solanum tuberosum)

Potato tubers (potatoes) are grown on large areas in the world, primarily for human
consumption. But they can also be used for feeding animals, in particular ruminants and pigs.
Potato tubers are highly variable in shape and colour. There are four shape types:
compressed, round, oval and long. The shape is important for the processing of potatoes.
Potatoes skin colour varies from yellow to pink or purple.
For animal feeding, potatoes size is the most important factor, since small ones may
produce oesophageal obstructions.
 Among feeds from this group, potatoes have a relative higher content in dry matter, 18-
24%. In the dry matter starch predominates (70-80%), compared to glucose and sucrose in the
roots.
Raw potatoes starch is resistant to digestive secretions, especially in monogastric
animals and arrived in the small intestine, they can induce health problems.
The protein content of potatoes varies between 9 and 12% CP in DM, with an average
value of 11%, with the specification that is of relatively good quality.
The level of crude fiber is low, as well as minerals, particularly calcium.
Potatoes contain an anti-nutritional factor, solanine, which can cause gastroenteritis in
pigs (the level of this alkaloid increase if the potatoes are exposed to the sun). The risk is
considerably reduced if the potatoes are boiled before being administered to pigs. Ruminants
are more resistant to solanine, probably due to its inactivation in the rumen, so potatoes can be
administered and raw for these animals.

Sweet potato tubers (Ipomoea batatas)

Sweet potato tubers (sweet potatoes) are grown in tropical, subtropical and temperate
regions and are used primarily in humans’ diets, in various forms (boiled, baked, fried, flour),
but partly are used in animal feeding.
Raw sweet potatoes are consumed with pleasure by pigs and cattle for their pleasant
taste, but they can be incorporated, in dehydrated form, in compound feeds for all animal
species.
Tubers of sweet potato are rich in starch and have different sizes, shapes and colors.
Sweet potatoes have nutritive values quite similar to classic potatoes, however, with a
slightly higher content in dry matter (even 30%).
New varieties of sweet potato tubers produce more edible energy per hectare than any
other major feed crop and 30% more starch/ha area than maize.

Cassava (Manihot esculenta)

Cassava, also known as manioc, is a tropical and subtropical plant used for its tubers. In
the mentioned regions, it is a very important food for humans (from cassava is prepared
tapioca).
But cassava can be used in animals’ diets, including cattle, pigs, even birds (for the latter
in dried form). For monogastric animals in dried form, there is a partial replacement of cereal
grains.
In cassava dominates carbohydrates, and of these about 80% is starch (in dry matter).
The protein content is lower than that of the potatoes.
Removal of tubers from the ground should be done carefully because these are easily
deteriorating.
 Jerusalem tubers (Helianthus tuberosus)

Jerusalem tubers can be harvested once the leaves have dried, from late summer to
spring (in regions where the soil is not frozen).
In contrast to potatoes, Jerusalem tubers do not store energy in the form of starch
(consisting in chains of glucose), but in the form of inulin (a polymer consisting of chains of
fructose), which is why it is recommended for diabetics.
After extraction of a protein isolate from the leaves of Jerusalem tubers, results a by-
product that constitutes a potential feed for animals.
Jerusalem tubers and the aerial part of the plant have long been used in the human’s
diets and in rations of cattle, sheep and pigs.
In the last years very high Jerusalem tubers yields were obtained, even up to 50-70 t/ha.

By-products of roots and tubers

Sugar beet pulp

Fresh sugar beet pulp has high water content (85-90%), which creates transportation
problems and storage problems. To reduce the impact of these disadvantages, fresh pulp can be
pressed in order to reduce the water content at 75-80%. The best solutions are, however,
dehydration or ensiling.
Dehydrated sugar beet pulp has about 88-90% DM, crude protein content is 9-10% in
DM (relatively low, but good quality) and crude fiber content is 19-20% in DM (relatively
high).
In the dry form, the beet pulp can enter in the structure of the complete compound feeds
for all animals.
In the granulation (pelleting) process of dehydrated beet pulp, molasses can be added,
becoming a more valuable feed. Dehydrated sugar beet pulp that contains molasses is called
molassed sugar beet pulp or molassed beet pulp pellets.
For all animal species, especially for horses, if larger quantities of dry sugar beet pulp
are used and they are administered separately is advisable to be soaked in water, because have
a high absorption capacity (can cause dehydration of the body).
In pigs, dehydrated sugar beet pulp has a favorable influence on digestive tract motility,
which is especially important for pregnant sows.
Ensiling is a way of preserving fresh beet pulp. Typically, when the silage is making,
sugar beet pulp is compressed or added dried feeds (straws, for example) to reduce the water
content.
 Molasses

Molasses is a by-product obtained by sugar extraction from sugar beet juice, through
consecutive processes of evaporating, crystallization and centrifugation.
Molasses is a liquid feed, but with a higher dry matter content, 70-75%. More than half
of the dry matter consists of soluble sugars, in particular sucrose. The protein content is very
low, 3-4% in DM, most of which is structured into non-protein nitrogen.
Molasses is the only vegetable feed that not contains practically crude fiber.
The most abundant mineral is potassium, about 4.5-4.7% in DM (half of the ash
content), which gives laxative and diuretic properties.
For animals, molasses has notable nutritive properties and high intake capacity. Because
of its viscosity, it is difficult to handle, so it is rarely used alone, often in combination with
water and other feeds, including those known for their low level of consumption, such as straws.
Molasses also is used as a binder in the production of pelleted compound feeds, intended
for all species and categories of animals. Obtained granules are more difficult to break and leave
less dust during transport. By the high content in saccharose of molasses, compound feeds
become more attractive to animals, which are important for some categories, such as piglets.
Solidified molasses is a component of lick briquettes for ruminants, alongside with other
ingredients like table salt, other mineral salts, urea, and vitamins.
It is also a good silage additive for plants with a low content of water-soluble
carbohydrates. It should not be included in maize or sorghum silages, because the surplus of
simple carbohydrates brought by molasses allows the development of yeasts.

Potatoes pulp

Potatoes pulp is a by-product obtained from the extraction of starch. It is produced in

considerable amounts worldwide.
In terms of composition, obviously non-starch products are predominant, headed by
cellulose, hemicellulose and pectic substances, more than 50% in the DM. But starch "tied",
which cannot be extracted, is an important component, about 30% in the DM. Other nutrients
found in potatoes pulp are proteins (4-5% in DM), fats (less than 1% in DM) and minerals.
The main problem with fresh potatoes pulp, like the fresh beet pulp, is the very high
content in water, 80-90%. So, it is used in animal feeding less in this form (in addition does not
taste, with a lower palatability).
Usually, potatoes pulp is used in dehydrated form or as silage. In the dehydrated form,
can be part of the compound feeds. Potatoes pulp silage, beyond the fact that is a way of
preservation, has favorable effects on the productive performance of lactating cows..
 Concentrate feeds

Compared to volume feeds, concentrate feeds have in the natural state (as basis) higher
nutritional values.
The main concentrate feeds groups are:
* Cereals and related by-products
* Leguminous seeds, oilseeds and related by-products
* Milk and milk by-products
* Animal meals and fats
It must be remembered and compound feeds, combinations between the groups of
concentrates presented (but also other sources).

Cereals and related by-products

Cereals are the seeds of annually grasses, and are among the most important sources of
nourishment both for humans and animals.
In the case of humans, the cereals provide almost half of the nutrients needed worldwide
(about 47% of the energy requirement and about 43% of the protein requirement), according
to.
Cereals production on global level in recent years recorded more than 2.5 billion tons
per year, of which maize holds about one billion tons. The following are rice (about 750 million
tons) and wheat (about 710 million tons).
The dry matter (DM) content of mature cereals is 12-14%. Carbohydrates are the
dominant component in DM, about 75-80% (majority being starch).
Starch (mainly as amylose and amylopectin) is found in granular form, with different
ratios between amylose and amylopectin. By genetic manipulation, different hybrids were
produced (especially for wheat), those who have 100% amylopectin, which is important in the
baking process.
The second major group of constituents is proteins, which hold on average 9-14% in
DM, although some cultivars of wheat contain as much as 20% CP in DM. Cereal’s proteins
are deficient in certain essential amino acids, particularly lysine and methionine.
Crude fiber is found in varying proportions, 2-10% in DM.
The lipids content of cereal grains varies with species. Wheat, barley, rye and rice
contain 2-3% lipids in DM and maize and oat 4-6% in DM.
The cereals are all deficient in calcium, containing less than 1 g/kg DM. The phosphorus
content is higher, being 3-5 g/kg DM, but part of this is present as phytic acid (difficult usable
in the body). The cereal grains are deficient in vitamin D and, with the exception of yellow
maize, in provitamins A. Also, they are good sources of vitamin E and thiamin (vitamin B1),
but have a low content of riboflavin (vitamin B2).
We present, in Table 31, nutrients content of some cereals, namely: crude protein (CP),
ether extract (EE), available carbohydrates (ACH), crude fiber (CF) and minerals, where
notable differences can be noted.

Table 31 - Cereal content in the main nutrients (by reference to dry matter)

Specification Maize Wheat Rye Barley Oat Rice

CP (%) 10.1 13.0 10.8 12.8 12.4 8.9
EE (%) 4.4 2.1 2.0 2.4 8.3 2.5
ACH (%) 73.6 67.7 69.9 70.9 64.6 84.6
CF (%) 10.3 15.2 15.1 11.1 11.3 2.5
Minerals (%) 1.5 2.0 2.2 2.6 3.3 1.4

The main cereals and their by-products will be presented further, rather in the order of
their use in animal diets in Europe than worldwide.

Maize and related by-products

Maize (corn)

Maize is the main cereal used in animal diets.

In fact, maize is considered a standard component of livestock diets, the other feeds
being reported to it, especially when energy is considered.
There are different varieties of maize, with seeds in different colors: yellow, white and
red.
Yellow maize is the most common variety. This one contains some pigments, like
cryptoxanthin and zeaxanthin, precursors of vitamin A and responsible for the coloring of egg
yolk, chicken carcass skin and fat.
It should be noted that, in recent years were created many cultivars of maize, from which
“dent corn” is the most widely grown type and typically used for animals. Other types (flint
corn, popcorn, sweet corn) are more intended for humans.
Maize contains about 73% starch in dry matter (DM), giving it a high energy value
(among cereals), about 1.22 LFU/kg DM.
Maize starch is digested more slowly in the rumen, compared with that contained in
other cereals, and a higher proportion from it reaches in small intestine, where is digested and
absorbed as glucose.
 The average protein content of maize is 9-10% in DM, although there are varieties with
higher protein level (and essentially amino acids). For example, are worth remembering
varieties Opaque-2 (higher content in lysine) or Floury-2 (higher content in lysine and
methionine).
Fat level in maize fluctuates between 4 and 6% in DM, but the latest varieties have
more.
Linoleic acid and oleic acid, unsaturated fatty acids present in the maize fat, are
responsible for the production of soft consistency fat in pigs (unpopular among consumers).
Therefore, in the last part of fattening it is recommended to remove or restrict maize in pig’s
rations.
Maize can be used in diets of all species and categories of animals, in various forms,
such as whole grains, milled, crushed or processed (in particular by thermal treatments).
When maize is harvested before full maturation of the grains, can become infected with
the fungus Aspergillus, whose toxin (aflatoxin) can cause health problems in animals, especially
on the reproductive function level and on the immune system.
Maize was among the targeted plants for genetic manipulation, in order to improve
productivity and resistance to diseases and pests.
In many countries, genetically modified maize has been banned, in others has returned
to cultivation, and in others occurs without restrictions.
The problem of using or not using in humans and animals’ diets of genetically modified
maize (generally all plants) remains controversial.
Some positive impacts have been reported for genetically modified maize, notably a
reduction in herbicide and pesticide use, and certain benefits for wildlife.
However, potential negative effects have also been alleged, including the alteration of
the DNA of soil micro-flora, and deleterious impacts on useful insects, such as butterflies and
bees, or on non- genetically modified plants (including maize) through genome transfer.

Maize by-products

In industries producing starch, glucose and alcohol from maize result several by-
products, which may be used in animal feeding, but also in the human's diets, like: maize germs,
maize gluten feed, maize gluten meal, maize bran and maize distiller's grains.
Maize germs
Maize germs are obtained by wet milling (in the production of starch) or by dry milling
(in the production of maize flour).
Maize germs are very rich in fat (45-50% in the DM) and average protein content is 12-
14% in the DM.
Most often, maize germs are used for the extraction of oil for human consumption (is
considered a quality oil).
 After extraction of the oil, result maize germ meal, intended for animal consumption.
Maize germ meal can be sold separately on the market or mixed with other by-products,
resulting hominy maize.
Maize gluten feed
Maize gluten feed is the by-product of the wet-milling of maize grains for starch or
ethanol production, consists mainly of maize bran and maize steep liquor (liquid separated after
steeping), but may also contain distillers soluble or maize germ meal.
Maize gluten feed is an ingredient mostly used in cattle diets as a source of energy and
protein.
Maize gluten meal
From maize can result maize gluten meal, a by-product obtained after production of
maize starch (and sometimes ethanol), by the wet-milling process.
Maize gluten meal is a protein-rich feed, containing about 65-70% crude protein (in
DM), used as source of protein, but also source of energy and pigments for livestock species. It
is also valued in dry pet food for its high protein digestibility.
Maize bran
Maize bran (shell maize grains) can be produced in industrial processes undergone the
maize. However, marketed maize bran contains and other by-products, which mean that, have
a variable composition.
Maize distiller's grains
Maize distiller's grains are the most important by-product obtained after the extraction
of alcohol.
This is a feed with high protein content (about 30% in DM), relatively high fat content
and relatively low crude fiber content, which makes it a feed suitable for using in the diets of
all species and categories of animals.
After distilling the alcohol, a liquid “used” remains, which is often mixed with maize
distiller's grains, both are dried to give a by-product called dried distiller's grains with soluble
(DDGS), used in the diets for all animal species.
With the new ethanol extraction processes (fats and crude fiber are separated in the first
manufacturing process), the protein level increase in the product (even at 45% in DM), resulting
a product called high protein distiller's grains (HPDG).
 Barley and related by-products

Barley

Barley is a cereal widely used in animal nutrition in many countries. In Northern and
Western Europe barley is the main cereal intended for ruminants and pigs. Barley is used also
in the current feeding of other species of animals (horses, rabbits, etc.).
In the system of fattening young cattle, called “barley beef”, are used in rations large
amounts of concentrates, dominated by barley.
Barley is indicated cereal for fattening pigs, because it has as effect producing a more
consistent fat, favored by consumers.
The protein content of barley is about 11-12% in DM, higher than in maize. As in the
case of other cereal grains, barley protein (hordein) is deficient in lysine (primary limiting
amino acid). But now were created varieties with higher content in lysine, like Notch 1 and
Notch 2.
Barley varieties with six rows of grains have higher protein content and are suitable for
animal feeding, and those with two rows of grains have higher starch content and lower protein
content and are therefore preferable for manufacturing beer.
The content in crude fiber and minerals is something higher than in maize, but starch
content is lower.
Barley grains are hard, because of solidity of the shells, so should at least be crushed to
digest by animals in a greater proportion. Wet (steam) or grinding processes are more efficient.
After grinding the barley, this can be sifted and results a finer fraction, with 2-3% crude
fiber (suitable for using in poultry and pig feeding), and a coarser fraction, with 10-11% crude
fiber (recommended for ruminants).
Compared to other cereals, barley contains higher amounts of beta-glucans (up to 8%
in DM), anti-nutritional factors that increase the viscosity of intestinal contents. Their effect is
more pronounced in birds, by the appearance of sticky faeces.

Barley by-products

Barley by-products derive mainly from the beer industry and the alcohol industry.
Barley by-products from brewing industry
The main by-products derived from brewing barley industry are: barley germs, barley
brewer’s grain and barley yeast.
Barley germs are nucleus of the seeds (barley before being subjected to processes for
producing beer is degerminated).
 Barley germs contain relatively large protein content (28-30% in DM), some essential
amino acids, vitamins (especially vitamin E and B complex) and some polyunsaturated fatty
acids (but these are the cause of the oxidation, depreciation of the germs stored more time).
Barley brewer’s grain in the first instance (fresh) contains about 75-80% water and can
be administered to cattle (specially to lactating cows), sheep, horses, but as soon as possible (at
2-3 days from its production if the ambient temperature is high, otherwise it is easily damaged
by infestation with bacteria and fungi). Ensiling or drying can be solutions to prevent this
situation.
Barley yeast, a liquid feed in the first instance, is separated from the fermented juice
(from which will produce beer) and inactivated with organic acids. If it is not inactivating, could
create health problems in the animals (abnormal fermentation in the digestive tract).
But most often, fresh barley yeast is dried and removes the inconvenience. In this
dehydrated form, yeast has about 40-50% protein in DM, is rich in B vitamins and phosphorus.
Dried barley yeast can be irradiated, thus becoming an important source of vitamin D.
It is used in dehydrated form, especially in pigs and poultry compound feeds.
Barley by-products from alcohol industry
From the alcohol industry (whisky, ethanol) where the raw material is barley, resulting
as a by-product, barley distiller's grains, similar to barley brewer’s grain from brewing industry,
used in particular in lactating cows' diets, either fresh or as silage.
It should be noted that, barley dried distiller's grains with soluble (DDGS) is produced
on a smaller scale than the similar one from maize, because of its composition (less starch
content, higher crude fiber content, and higher beta-glucans content).

Wheat and related by-products

Wheat

Wheat, along with maize and rice, is the most cultivated cereal in the world, but only
about 25% is used for animal feeding, the difference being intended for human consumption
(in Europe is almost parity).
Should be noted that "hard" wheat (Triticum durum) is used primarily to humans, being
suitable for the pasty making, while "soft" wheat (Triticum aestivum), with less hard coating,
is directed towards the production of bread and animals feeding.
Due to very early selection for specific traits, wheat grains are highly variable in colour,
form and starch types.
Protein content of wheat oscillates between 10 and 14% in DM, with the specification
that the new strains have 20% CP in DM. Anyway, the wheat protein is greater than in maize.
 The main proteins of wheat, glutenin and gliadin, forms with water a viscous mass. This
fact determines the use of wheat for bread making. If the content in these proteins is higher, is
more suitable for bread industry.
For this reason (sticky property), if the wheat is administered in animals’ diets in too
large quantities can cause digestive disorders, because during digestion process, the intestinal
peristalsis is affected and the absorption rate decreases.
Fat content in wheat is reduced, 2-2.5% in the DM, about half of the maize. Wheat fat
contains relatively large amounts of oleic acid and linoleic acid, which can easily oxidize.
The predominant mineral is phosphorus and predominant vitamins are B complex and
vitamin E.
The energy nutritive value of the wheat is a little smaller than of the maize, about 1.18
LFU/kg DM.
Wheat can be used in animals’ diets sometimes whole (in birds or sheep) or can be
processed in different ways (milling, extrusion, etc.). Milling too fine can cause adverse effects
in animals (digestive disorders), especially in ruminants and pigs (birds are less exposed).
The inclusion of wheat grains in the diets depends on the relative market prices of the
major grains. When maize, barley and sorghum are more expensive, wheat becomes a valuable
option.

Wheat by-products

In bread industry, first is separated from the whole wheat grains three fractions:
endosperm (about 82%), bran (about 15%), and germs (about 3%).
From endosperm is obtained white flour, used in the production of bread (wheat bran
can be added to this, more or less, and resulting brown bread).
Wheat bran
Typically, wheat bran results from the grinding of common wheat ("soft"), but also from
the processing of “hard” wheat.
Wheat bran has relatively high crude fiber content and is commonly used in the feeding
of cattle and horses. Not commonly is used in diets for pigs and poultry.
Due to the laxative properties, wheat bran is used for females in late pregnancy and in
the first days after birth.
Protein content in wheat oscillates between 16 and 20% in DM, anyway larger than in
grains of origin. Wheat bran has a high content of phosphorous and B vitamin complex, but a
low level of calcium.
For pleasant taste, wheat bran is accepted by the most species of animals.
Wheat bran obtained by traditional milling methods has higher nutritional values than
those obtained by modern technologies.
Wheat germs
 Wheat germs, a valuable feed, is characterized by high protein level (about 30% in DM),
and this easily digestible, high level of fat (about 10% in DM, with significant amounts of
vitamin E) and relatively low fiber content.
Sometimes the oil is extracted from the wheat germs and results wheat germ meal.
Wheat distiller's grains
Wheat distiller's grains, other by-product, is rich in protein and crude fiber, but poor in
fat, and can be used in diets of most animal species and categories.
As in the case of maize or barley, from wheat can also be prepared DDGS. This one at
first was used in ruminant rations, but with the accumulation of new information it became an
interesting feed source for non-ruminants animals, especially pigs.

Oat and related by-products

Oat

Oat is the sixth cereal grown worldwide, in Eastern Europe traditionally, after maize,
rice, wheat, barley and sorghum.
The largest quantity of oat is intended for animals, but is used also in human diets, as
oat flakes. Typically, oat is not used in the production of bread and alcohol.
When oat comes to animals, it is used in particular in ruminants and horses’ diets, less
for pigs and poultry, due to its characteristics.
Among cereal grains, crude fiber content is high (13-14% in the DM) and nutritive
energy value lower (about 0.9 LFU/kg DM).
Oat protein (about 10-11% in DM) has low quality, like as in the case of all cereals.
Oat (among cereals) has high fat content, of the order of 5-6% in DM, similar to maize.
This fat is rich in unsaturated fatty acids (oleic and linoleic) and induces a softer fat consistency
in pigs.
Minerals are present in oat in slightly larger quantities than in other cereals, including
phosphorus, potassium, even calcium.
There is a variety of oat, called “naked oat”, with a lower content in crude fiber, but
with a higher content in protein and fat. It is more suitable for using in diets of monogastric
animals.

Oat by-products

After milling of whole oat, result as the main by-products oat hulls and oat bran.
Oat hulls are obtained most often by mechanical separation of grains itself by the
coating of grains. But, can also be obtained by steaming or roasting.
 Because crude fiber content is very high, 35-40% in DM, oat hulls are designed
especially to ruminants.
Oat bran is obtained by separating the shell of the grains and can be included in the
rations of herbivores. Part of the endosperm is also found in oat bran, up to 25% of the total
weight of the grains.
Oat bran is used successfully by humans who need hypoglycemic and
hypocholesterolemic foods, but also due to their high content of B-complex vitamins.

Rice and related by-products

Rice

Rice is the most widely cultivated cereal in Asia, especially for human consumption.
For livestock animals rice is used on a small scale, in particular for ruminants and
horses.
But rice is the main cereal incorporated in the dry food for dogs and cats, for high
digestibility, its protein does not cause allergies and for anti-diarrheal properties.
After threshing rice has a fibrous shell, like oat, and at this stage is raw rice (used for
ruminants and horses). After removing the fibrous shell (husks) result brown rice
(recommended for pigs and pets) and further after separation of endosperm and bran is obtained
polished rice (that which is found in stores for humans).
Polished rice has a very high starch content, about 80-85% in DM, a very low content
of crude fiber (less than 1% in DM), but by removing the bran, the content of fat, minerals and
B complex vitamins decreases significantly.

Rice by-products

The main by-products derived from rice are: rice bran and rice hulls.
Rice bran, the most important by-product, contains 14-15% crude protein in the dry
matter and not less than 14-18% fat in the dry matter (large amounts of unsaturated fatty acids
are found, which can cause rancidity).
This is one of the reasons why rice bran is defatted (reaches to 2-3% fat in the DM) and
apart from the fact that it is easier to store, can be introduced in larger quantities in animal
rations.
Rice hulls have a very high content of crude fiber and silicon and an irritating effect on
the mucous membranes. However, rice hulls can be used in the diets of adult herbivores.
In some countries, especially those that traditionally grow rice, its processing is done in
a single step, resulting as a by-product a mixture of rice bran with rice hulls.
 Rye and related by-products

Rye

Rye is grown especially in Europe and North America in unfavorable areas for other
cereals.
The countries that produced the largest amount of rye were Russia, Germany and
Poland, about 64% of world production of 13 million tons/year.
Rye is used usually in human nourishment, the second cereal after wheat for the
production of bread (in northern and eastern Europe in particular).
Rye is used also in animal diets, but in limited quantities. Through cereals, rye has the
lowest level of consumption.
Normally in birds’ diets should not be used, because has a depressive effect on the
appetite.
Rye may become contaminated with fungus Claviceps purpurea, whose toxin called
ergot (a mixture of alkaloids), is involved in abortions producing.
Rye, in terms of composition is quite similar to wheat, although the protein level is
slightly lower (9-10% in DM). Despite this, the level of lysine is slightly higher.
The content in nitrogen free extract is very high, 80-85% in the DM, with the mention
that a part is represented by xylans and arabinans, with a lower degree of digestibility.

Rye by-products

From the alcohol, brewing and pharmaceutical industries, which use as raw material
rye, results some by-products, similar to those of other cereal grains, but available in small
quantities.
From these by-products are only remembered rye bran (resulting from the baking
industry) and rye distiller’s grains (resulting from the extraction of alcohol).

Triticale

Triticale is a hybrid derived from crossing wheat with rye, whose name comes from the
scientific name of the two parental plants (Triticum and Secale).
Hybridization purpose was to maintain productivity and nutritional values of wheat and
better tolerance of rye to adverse growing conditions (triticale plants are more tolerant than
wheat to soil acidity and less dependent on the degree of fertilization).
Triticale can be used both in human diets (production of pasta, in particular) and in
animal feeding.
 The protein content for classic varieties is 11-12% in DM, lower than in wheat, but
newer varieties of triticale have a protein content at least equal to that of wheat, but the quality
of the protein is better, having a higher content in lysine and in sulfur amino acids.
As with other cereals, the dominant fraction in triticale is nitrogen free extract (75-85%
in the DM). The crude fiber content and fat content are relatively low, about 2-3% and 1.5-2%,
respectively (in the dry matter).
Like rye, triticale can become infested with Claviceps purpurea.

Sorghum

Sorghum is the main cereal used by humans in Africa and in parts of India and China.
The main reason is better drought resistance, thanks to a deep root system. For seeds is grown
especially common sorghum (Sorghum vulgare).
The other important varieties, sweet sorghum (Sorghum saccharatum) and Sudan grass
(Sorghum sudanense) are grown, predominantly, to be used as green forage or silage by
animals.
Sorghum seeds are small and with hard caryopsis. Therefore, it is processed before
being used as feed for animals. Common processing consists in: grinding, steaming or
extrusion.
In terms of composition and nutritive values, sorghum resembles with maize.
Sorghum seeds (the brown variety) containing tannins, anti-nutritional factors that
reduce the digestibility of proteins.
Therefore, brown sorghum seeds are not recommended to be used in the diets of young
animals, especially poultry, because induces growth retardation.
As in the case of maize or other cereals, after processing of sorghum results certain by-
products, such as sorghum bran, sorghum distiller’s grain, sorghum gluten feed, sorghum gluten
meal or sorghum germ meal.

Cereals processing

For a long time, cereals were treated by simple techniques, like grinding or milling.
More recently a number of other techniques have become available, and can be classified into
two types: heat treatments and cold treatments.
Heat treatments
Heat treatments include: flaking, micronisation, roasting, extrusion and expansion.
Flaking is usually applied in the treatment of corn (corn flakes) and consists in using
steam, passing through rollers and then drying. This process leads to increased digestibility.
 Micronisation is an advanced process using radiant heat, where starch granules are
reduced to microscopic dimensions (several microns), in order to increase absorption in the
body (micronized particles become more easily accessible to the action of digestive enzymes).
Roasting of cereals is one way to increase the availability of starch in the body,
especially in young animals, especially in piglets.
Extrusion is a heat plasticization of cereals and their pressing in various forms.
Extruded cereals have beneficial effects on the productive performances of the animals,
especially poultry (influences the growth rate and feed efficiency ratio).
Expansion is a process where cereals are subject to very short time (seconds) at high
temperatures and pressure in order to increase their availability in the body.
Expansion also provides high resistance to the aggressions of pathogenic micro-
organisms, including molds.
Cold treatments
Cold treatments refer to: milling, cold pelleting and addition of organic acids or alkali.
Milling cereals is essential for achieving high productive performances in animals.
The milling should not be excessive (very fine), because it produces dust, which can
cause irritation of eye and gastrointestinal mucosa. More seriously, particularly for maize and
wheat, very fine grinding can cause esophageal ulcers in the stomach region.
For horses, grain milling is required to be better digested in the small intestine and to
avoid getting undigested in the large intestine (if the starch gets here, it is fermented by micro-
organisms and acids are produced, including lactic acid, which lowers the pH and mucosal
irritations can occur). Oat may be administered whole to horses, because the grain size and
shape allows chewing and its starch, consisting of small granules, is more easily digestible to
this species.
It is accepted that for cattle, cereals must be coarse milled (larger particles) to avoid
rumen acidosis. If administered whole to cattle a higher proportion is undigested.
In the case of sheep, grain milling has no obvious effects on their degree of using in the
digestive tract, because are better chewable.
Cold pelleting has some positive effects on productive performances of the animals, but
the effects differ among cereals.
Treatment with organic acids, such as propionic acid, is used in particular in the case
of cereals with high water content, in order to inhibit the development of molds.
Treatment with alkali, such as sodium hydroxide, is used as an alternative to mechanical
treatments, to decrease the negative effects of the hard coating cereal grains, such as barley.
Also, by alkali treatment, the endosperm is not exposed to the rapid fermentation in the
rumen, and are alleviated the conditions of acidosis appearance.
 Leguminous seeds, oilseeds and related by-products

Leguminous seeds

Leguminous seeds (grains of annual leguminous plants) are primar sources of

protein for animals (20-35% CP in DM).
Lysine has a relatively high level; however, the sulfur amino acids content
(methionine, cystine) is settled to relatively low level.
The minerals content, including calcium and phosphorus, is slightly higher than
those in cereals and in a more convenient ratio.
Leguminous seeds are characterized by a relatively high content of B complex
vitamins and a low content of vitamins A, D and C.
Most leguminous seeds contain some anti-nutritional factors, which may affect
animal health and productive performances, which is why these are subjected to
treatments before being administrated to animals. Among these anti-nutritional factors
there are worth mentioning: proteases inhibitors, tannins, lectins, saponins.
In the following, references will be made to peas, vetch, fababeans, lupin and
beans.

Peas

Peas (like grains) represents an important source of protein in Europe, in order

to replace soybeans meal, coming especially from the USA and China.
Peas has a great genetic diversity, with more varieties. Seeds can be green,
yellow or brown, with different shell thicknesses and varying sizes.
Protein content of peas is about 20-25% CP in the DM, with a medium
biological value, due to the relative low methionine content (lysine relative high level).
The main fraction, nitrogen free extract (NFE), 60-65% in the DM, is
dominated by starch.
The crude fiber content is low (about 5-6% in DM) and the fat content is also
very low. Vitamins B content is relatively high.
Energy nutritional value of peas is about 1.2 LFU/kg DM (like maize).
In animal diets, peas can be used unprocessed or processed.
The usually processing methods used are mechanically (milled, decorticated)
and heat treatment (roasted, micronized, extruded, pelleted).
For monogastric animals, the main purposes of processing are to reduce the
content of anti-nutritional factors (proteases inhibitors, lectins, tannins) and to increase
nutritive values.
 Proteases inhibitors are the best inactivated by autoclaving at 100° C, for 15
minutes, while the lectins can be destroyed by extrusion (requiring for this higher
temperature).
For ruminants, heat treatments reduce degradability of protein in the rumen,
therefor it increases its use in the small intestine. However, these treatments increase
rumen degradability of starch, which is considered a disadvantage.
Peas can be used in diets for all animal species and categories, but restricted.
It is recommended to be incorporated into concentrates mixtures or in
compound feeds in proportions of 10-15% for young animals and 20-25% for adult
animals.

Vetch

Vetch is grown especially for green mass, but occasionally in animal diets can
be used as seeds.
Vetch seeds contain 28-35% CP in DM (more than peas), 60-65% nitrogen free
extract, 6-7% crude fiber, about 1.5% fat and 2-3% minerals (all these in relation to dry
matter).
Vetch has a high content in anti-nutritional factors, like vicin, convicin, tannins
and cyanogenic glycosides. The latter affect the central nervous system and causing
muscle rigidity (especially in birds). It has also a bitter taste, so the animals do not eat it
with pleasure. Used in larger amounts in the diets of lactating cows, vetch can induce a
bitter taste to milk.
Because they predispose animals to constipation, vetch seeds are not
recommended to be used in diets of females in late gestation and for young animals.

Fababeans

There are two varieties of fababeans: with big grains (used primarily by
humans) and with small grains (used in particular as animal feed source). Fababeans
has a slightly higher crude protein content than peas, 28-30% in DM, where lysine is at
a relatively high level. The level of crude fiber is 6-7%, of lipids about 1.5%, and of
minerals 3-3.5% (all in the dry matter).
However, fababeans has higher content in some anti-nutritional factors
(tannins, vicin, proteases inhibitors). Because of this fact, this feed is used less in pigs
and poultry diets, although there were created varieties with a lower content in these
anti-nutritional factors.
In laying hens, vicin causes a decrease in eggs size and eggs production, as well
as a weaker use in the body of certain minerals (e.g., iron and zinc).
 The grains of fababeans are recommended primarily in horses’ rations (is also
called "horse beans"), lactating cows and fattening cattle, in similar proportions to
those underlines in peas.

Lupin

Lupin seeds have a particular composition among other leguminous seeds.

Thus, they have higher protein content (35-40% in DM) and a relatively low content of
nitrogen free extract (35-40% in DM). Also, the fat and crude fiber content are
relatively high (12-13%, respectively 7-10% in DM).
Lupin contains some anti-nutritional factors, in fact alkaloids, such as lupinin
and anagirin, these having adverse effects on animal health, fact demonstrated in
gestation cows.
Bitter lupin varieties are not included usually in animal diets, due to the high
content in alkaloids. There are also varieties of "sweet” lupin, which can be used in
animal rations, but limited.
Maximum recommended levels in compound feeds or in concentrate mixtures
are 15% for ruminants, 10% for pigs and adult birds and 5% for youth pigs and poultry
(to a greater extent may affect the taste of meat, milk and eggs).

Beans

Beans are used primarily in humans’ diets as a source of protein, minerals and
vitamins. Occasionally it can be used in animal diets.
Beans seeds derive from several varieties (spring and autumn).
The spring varieties have a higher protein content (about 26-27% in DM),
compared to the autumn varieties (23-24% in DM).
There are many varieties of beans that contain anti-nutritional factors (proteases
inhibitors, lectins), which produce adverse effects on humans and animals. Therefore,
there are recommended boiling, baking or other methods of preparation.
Beans can be included in animal rations, but restricted, at the same levels
presented in the case of peas.

Oilseeds

Oilseeds (oleaginous seeds) are distinguished mainly for their high fat content
(20-45% in DM), which gives a very high energy value.
 Using oilseeds as whole in animal diets is limited, because there are intended in
particular to extraction of oils. Another reason for which oilseeds are used in limited
quantities in animal diets is related to the fact that contain some anti-nutritional factors.
The main feeds of this group of concentrates are soybean(s), sunflower seeds,
rapeseed, linseed, safflower, cotton seeds and peanuts.

Soybean

Soybean is the main oilseed cultivated worldwide, lately being obtained about
280 million tons/year (the biggest producers are USA, Brazil, Argentina and China.
Soybean is used both in human diets (in various forms), as well as in the animal
diets.
In animal feeding, most often it is used as soybean meal, by-product after oil
extraction. However, due to the increase of soybean oil stocks at one point, the
possibility of using the soybean as whole seeds in animal feeding occurs.
In addition to the high fat content, 20-22% in DM (which gives a very high
energy nutritional value, about 1.45 LFU/kg DM, soybean is characterized by a
remarkable level of protein, about 35-40% in DM. Nitrogen free extract represents
25-30%, crude fiber 5-7%, and minerals 4-5% (in the dry matter).
Soybean fat contains large amounts of polyunsaturated fatty acids, mainly
linoleic acid.
In the soybean protein, lysine is at a high level, but the sulfur amino acids are
relatively low. In spite of this, the soy protein has a great quality.
Whole soybean can be used in animal feeding in two forms: untreated or
thermal treated.
Untreated whole soybean can only be used in diets for ruminants with fully
developed digestive tract, because the anti-nutritional factors (trypsin inhibitors,
lectins, allergic proteins) are inactivated (at least partially) in the rumen.
Heat treated soybean (full-fat soybean) has higher quality, because
anti-nutritional factors are destroyed, fat is stabilized and protein degradability in the
rumen is lower. Heat treated soybean can be used in diets for all species and categories
of animals.
For monogastric animals, especially for growing pigs and chicken, inactivation
of anti-nutritional factors found in soybean can be done through heat treatments
(toasting, micronizing, flaking, extrusion). The temperature during the processing must
not exceed 140o C, because induces a decrease in protein quality.
For ruminants heat treatment soybean, by reducing protein degradability in the
rumen, increases protein by-pass (protein reaching the small intestine), which is very
important for some categories of animals, such as high yielding cows.
 Sunflower

Sunflower is grown in many regions of the world, the largest producers being
Russia, Ukraine and Argentina, together holding over 50% of world production.
Sunflower seeds of the classic varieties have a very high fat content, 40-45% in
DM, and are intended primarily to oil extraction. After this, the result is sunflower
meal, a well-known source of protein.
High fat content gives to sunflower seeds a very high energy nutritive value,
about 1.55 LFU/kg DM.
The main fatty acid in sunflower fat, belonging the conventional varieties, is
linoleic acid (60-70% of total fatty acids), followed by oleic acid (15-25%). There have
been created varieties with a high content of oleic acid, becoming the first fatty acid.
The fatty acid profile of sunflower fat is very interesting and can improve the fatty acid
content of cow's milk or beef meat.
The protein content of the sunflower seeds, by reference to DM, is 16-20%, as
well as the content in crude fiber. If the protein level is relatively low (among oilseeds),
the level of crude fiber is high.
Sunflower may be shelled (decorticated), partially or totally, in which case the
protein content increases and crude fiber content decreases. But this process is costly,
and more recent varieties are harder hulling (decorticated).
When whole sunflower seeds are used in animals’ diets, they are destinated
usually to adult ruminants, about 10-15% in the concentrates’ mixtures or in compound
feeds’ structure. Also, they can be used with great results, in decorticated form, in diets
for monogastric animals.
In order to improve nutritional values, sunflower can be subjected to thermal or
chemical treatments (formaldehyde, for example).

Rapeseed

Like sunflower, whole rapeseed seeds are used on small scale in animal feeding.
Energy value is very high, about 1.8 LFU/kg DM, due mainly to high content in
fat, 40-45% in DM. The protein content is about 20-21% in DM (and this of good
quality), the crude fiber is 8-10%, and the content in nitrogen free extract is 15-20%
(dry matter basis).
Rapeseed is recommended to be used restricted in animal diets.
The main reason for restricting rapeseed in animal rations is the presence of
some anti-nutritional factors (glocosinolates, sinapin, erucic acid), which induce slows
growth rate and affects the kidneys, liver, heart and thyroid gland.
 However, there were created varieties with a low erucic acid level (varieties
"0") or varieties with a low erucic acid level and low glucosinolates level (varieties
"00"). The name "canola" assigned to rapeseed refers only to the double zero varieties
obtained by natural mixing, without any connection with genetic engineering.
In animal feeding, rapeseed is used primarily as a rapeseed meal, but it can also
be used in full form ("full-fat rapeseed" or "full-fat canola"). In the case of canola, it
may be included in ruminant rations in a proportion of 10-15% in concentrates
mixtures, but also in monogastric animals (pigs, poultry), to a smaller extent.
In order to improve the nutritional values and to reduce the content of residual
glucosinolates, rapeseed may be subjected to heat treatments.
Like maize, soybean or other plants, rapeseed was targeted to genetic
modifications.
In Europe, rapeseed is the main source of biofuel.

Linseed

Linseed (flaxseed) has a high content in fat, 30-35% in the DM (where linolenic
acid is present in a large proportion), and protein content is 20-25% in DM.
Also, it has a high content in pectic substances, components of nitrogen free
extract (NFE hold about 20-25% in DM).
Linseed is used both in human nourishment (additive in pasta) and in the animal
feeding, either as whole seeds or as linseed meal.
Relatively high content in pectic substances (this form with water mucilage, a
viscous mass) determines the use of linseed in dietetic purposes, especially in diets of
animals with digestive disorders, in young animals and gestation females in the last
part.
Linseed (flaxseed) has a favorable action on the hair and feathers, giving them a
special shine (important for exhibition animals and cage birds).
Because it contains some anti-nutritional factors, linseed is included in rations
in small quantities. Anti-nutritional factors, like linamarin or linustatin, affect the
nervous and muscle system.

Safflower

Safflower seeds are used both by humans (especially oil) and by animals, in
particular by birds, pets or rodents.
These seeds are too expensive to be used in farm animal’s rations. However, it
may be included in pelleted compound feeds, in order to prevent their breaking.
 In terms of composition, it is noticeable its high content in fat, 30-35% in
un-decorticated seeds and 45-50% in decorticated seeds (related to DM), where the
dominant fatty acid is linoleic acid (but is varieties with a higher content in oleic acid).
The protein content is, on average, 25-30% in DM.

Cottonseed

Cottonseed can be considered a by-product of the cotton industry.

From cottonseed seeds can be extracted oil (used for industrial purposes), in
which situation result a meal, cottonseed meal, used in animal feeding.
Cottonseed contains 25-27% protein and 20-25% fat (DM basis).
However, cottonseed contains some anti-nutritional factors, the most important
being gossypol.
Gossypol has various negative effects on the animals: decreasing availability of
nutrients in the body, affects the fertility and liver (hepatic degeneration). These are the
reasons why cottonseed is recommended to be used in small quantities, and for short
periods of time.

Peanuts

Peanuts are used usually as food for humans (as seeds or oil) or in different
industries (cosmetics, for example). They are rarely used as whole grains, in animal
feeding.
Peanuts seeds contain up to 50% fat in DM, dominated by oleic acid and linoleic
acid. Also, they have high protein content, about 30% CP in DM.
Peanuts contain some anti-nutritional factors, as well as antigenic proteins
(which may induce allergies). It infects easy with the fungus Aspergillus. This fungus
produces aflatoxin, which affects the liver and kidneys.
Lactating cows with high milk production are particularly susceptible to the
effects of aflatoxin. In addition, it is possible to be transferred into milk and may affect
humans.

Oilseeds by-products

Oilseeds by-products, also called meals, come from seeds after oil extraction
(more or less, depending on the technology used).
Oilseeds by-products have high protein content, which varies between 20% and
50% in DM, and represent an important source of feeds for animals.
 The crude fiber content is variable. In terms of vitamin content it has no
noticeable quantity.

Soybean meal

Soybean meal is the most important source of protein for animals worldwide.
In 2014, soybean meal production reached to 243 million tons and it represented
62.5% of the total oilseeds’ meals. Main producers were China (76 MT), USA (44 MT),
Argentina (33 MT), Brazil (33 MT), and EU-28 (12.5 MT).
The EU-28 was the most important importer of soybean meal (22 MT). In the
European Union soybean meal represented 61% of the protein sources used to feeding
livestock and 16% in the compound feeds structure.
There are two main processes to extract oil from soybean, to result soybean
meal:
The most common process consists in solvent extraction. This method is the
most efficient and about 1.5% oil is found in the resulting soybean meal.
The second method consists in a mechanical extraction, by a screw press
(expeller). This method yields less oil and soybean meal contain more than 5% residual
oil.
The level of nutritive soybean meal values cannot be reached by any other
source of vegetable protein. From this point of view, it is considered standard feed, and
all the other sources of vegetable protein are reported to it.
Soybean meal sold on the market is delimited by protein content (sometimes it
takes into consideration the fat content).
There are several types: soybean meal 44, 46, 48 and 50. The types with higher
protein content are obtained from decorticated soybean seeds (the content in crude fiber
is lower).
Soybean meal has a great value of essential amino acids, thus forming an ideal
structure with the cereals. However, methionine is at a lower level (this amino acid is
the primary limiting amino acid in soybean meal, in particular for birds).
Currently there are produced varieties of soybean with a higher protein and
amino acids content and the relationships between them are more convenient, which is
important especially for monogastric animals.
There are types of soybean meal with 55% crude protein and 3.6% lysine,
compared to classical varieties, which have about 47% protein and 3.1% lysine.
Like seeds, raw soybean meal contains anti-nutritional factors, especially active
for poultry and pigs. That is why they are thermally treated (not excessive because
decrease the availability of amino acids).
 Soybean meal thermally treated can be included in the rations for all species and
categories of animals, unrestricted nutritional (the restrictions are related only to the
price).
Normally it cannot miss in diets for poultry, pigs and lactating cows with very
high yields of milk.
The high degree of digestibility of amino acids allows formulating of rations
with lower levels of crude protein, which reduces the amount of nitrogen excreted in the
stool and urine.
By chemical extraction of the oil and by removal of the insoluble carbohydrates,
it result soybean protein concentrate, with about 70% CP in DM, without
anti-nutritional factors, making it suitable for inclusion in milk replacers for calves and
in compound feeds for piglets.

Sunflower meal

Sunflower meal is the fourth most important in the world, after soybeans meal,
rapeseed meal and cotton meal. The European Union is the largest producer (3.3
million tons per year) and the largest user.
There are many varieties of sunflower meals available on the market. There can
be un-decorticated or decorticated and in the same time the oil can be chemically
extracted, or by mechanically processes.
Sunflower meal decorticated (at least partially) and obtained by chemical
extraction is produced in the largest quantity.
In the European Union sunflower meal obtained by chemical extraction is
banned in organic farming.
In chemical extraction version, sunflower meal un-decorticated has about
30-35% crude protein and 20-25% crude fiber (in the DM).
If sunflower meal is decorticated results a product more digestible (with less
crude fiber content) and with higher level of protein.
As soybean meal, sunflower meal is sold based on protein content (there are
types 28, 30, 35, 37).
Sunflower meal is relatively deficient in lysine, the main limiting amino acid,
but has about two times more methionine than soybean meal.
One particularly interesting thing about sunflower meal is that practically it
does not contain anti-nutritional factors, as in the cases other meals (soybean, cotton,
rapeseed), which does not require heat treatment and a specific attention when is
administrated to certain categories of animals.
Because its composition, sunflower meal is recommended mainly in ruminant
and rabbits rations, but decorticated variants can be included in pigs and poultry diets.
 The maximum rate recommended for inclusion in compound feeds or in
concentrate mixtures is 20% for adult cattle, 15% for fattening pigs and 10% for adult
birds.
It is not recommended to be used in rations of young birds and piglets.

Rapeseed meal

The world production of rapeseed was in the last years about 33 million tons,
the most important producer being the European Union, with about 12 million tons.
Rapeseed meal from classic varieties has a bad reputation because of the high
content in erucic acid, glucosinolates and bitterness, resulting in severely restrictions
when it is used in animal feeding.
The latest varieties (double zero) have alleviated these negative traits, making it
widely usable in animal feeding (it is the second meal used worldwide, after soybean
meal).
Like other meals, the rapeseed meal can be obtained through chemical or
mechanical processes.
Rapeseed meal obtained by chemical extraction, compared to that obtained by
mechanical extraction, has slightly higher content in protein (about 38% versus 34%),
refering to the dry matter, and obviously lower fat level.

Cottonseed meal

Cottonseed meal is a common source of protein in traditional culture areas of

cotton, such as India, China, USA, Brazil, being a potential replacement for soybean
meal. These countries produce about 80% of the world production.
There are used several methods of oil extraction, slightly different than those
used for obtaining soybean meal or sunflower meal, resulting by-products with various
concentrations in protein, fat and crude fiber.
By reference to the dry matter, protein content varies between 37 and 45%.
Cottonseed meal is used primarily in adult ruminants’ diets, more tolerant to
gossypol. It can be used in diets for adult monogastric animals but limited.

Linseed meal

Linseed meal (flaxseed meal) is rich in protein (34-36% in DM), relatively rich
in crude fiber and variable in fat (depending on the extraction process).
The attractiveness of using flaxseed or flaxseed meal in animal feeding has
increased since it was found that it has high levels of poly-unsaturated fatty acids
(PUFA), especially in alpha-linolenic acid and conjugated linoleic acid, which have a
favorable action on fat quality of animals and thus on human health.
Linseed meal has favorable effects, such as laxative properties, dietetic
properties, and beneficial action on the skin, hair and feathers.

Peanut meal

Peanut meal obtained by chemical extraction has very high protein content,
about 50% in dry matter.
In terms of protein’s quality, peanut meal is characterized by a low content in
threonine (it has been used in this respect to induce the failure in this amino acid in
animals), with a relatively low content of lysine and methionine, but it is an excellent
source of arginine.
It was found that it is easily infested with the fungus Aspergillus, whose toxin
aflatoxin causes liver damage, especially to the youth and to the youth avian (peanut
meal must be excluded from their diets if it is infested). Peanut meal is mainly used in
the United States.

Palm meal

The palm oil can be extracted from the pulp of palm fruits (palm oil rich in
palmitic acid, 42-45% of total fatty acids), or from kernels (palm kernel oil, high in
lauric acid, 45-50 % of total fatty acids).
Palm oil, rich in saturated fatty acids (is semi-solid at room temperature), is
mainly used in human nutrition.
Palm meal resulting from oil extraction is used in animal feeding.
Palm meal can be obtained by chemical extraction or by mechanical extraction
(cake), the main difference being the fat content, 2-3% and 7-12%, respectively.
The palm meal obtained from the seeds has a high degree of fibrosis and
medium protein content, being recommended for the feeding of ruminants and rabbits.
 Animal feeds

Animal feeds are represented by whole milk (and related by-products), animal meals
and animal fats.
Whole milk and related by-products are sources of nourishment for young animals, as
well as for humans (especially cow's milk, sheep's milk, goat's milk).
Animal meals are used in relatively small amounts in rations, until the animal’s
requirements of some essential amino acids are covered, which cannot be supplied entirely by
feeds of vegetable origin.
Animal fats are used as a source of energy for some categories of animals.

Whole milk and milk by-products

Whole milk

Whole milk is the product obtained by milking females in good health, properly fed and
it must not contain colostrum.
Colostrum is the fluid secreted by the mammary gland during the first days after birth.
It is characterized by a different composition comparing to the whole milk, this having
specific traits (high nutritional values, immunological properties, etc.)
Cow’s colostrum, for example, immediately after calving, has about 33% dry matter
(DM) and 22% crude protein (CP), and after 6-7 days reaches about 12.5% DM and 3.2% CP.
Whole milk is dominated by the following components: water, fat, protein, lactose and
minerals.
Vitamins, enzymes and dissolved gases can also be found in smaller proportions.
Water holds the largest share in whole milk (80-90%), with minimum value in sow's
milk and with maximum value in mare's milk.
Fat content of whole milk is variable through species, ranging from 1.2% in mare milk
to 7.7% in buffalo milk (average values). Cow’s milk contains about 3.6% fat.
This means that (in relation to DM), milk fat represents about 12% in mare’s milk, 29%
in cow's milk, and 42% in buffalo’s milk.
Milk fat is dominated by triglycerides (96-97% from the total fat), with high proportion
of fatty acids with low molecular weight, those which provides an excellent source of energy.
The difference until 100% is covered by mono-glycerides, di-glycerides, phospho-lipids,
cerebrosides, free fatty acids.
Milk fatty acid profile is also different in milk fat. Anyway, regardless of species,
saturated fatty acids (SFA) are dominant, followed by mono-unsaturated fatty acids (MUFA)
and poly-unsaturated fatty acids (PUFA).
 Cow's milk contains, from the total fatty acids, about 70% SFA, 25% MUFA and 5%
PUFA, comparing to an ideal profile for humans, evaluated at 30% SFA, 60% MUFA and 10%
PUFA.
Therefore, through various means, especially nutritional, the specialists work on
changing the spectrum of fatty acids in milk, in the sense of raising the share of PUFA
(especially omega-3 and conjugated linoleic acid), considered natural anti-cancer agents and
protectors of cardio-vascular system.
Most of the unsaturated fatty acids (MUFA and PUFA) are in the cis form and less in
the trans form.
Protein (crude protein) content varies between 2.1% in mare’s milk and 5.5% in sow’s
milk. Cow's milk has about 3.2%. Obviously, these are average values.
So, in the dry matter of milk, protein represents 21% in the case of mare’s milk, 26% in
cow’s milk and 30% in sow’s milk.
From the total crude protein of cow's milk, "true" protein (consisting of amino acids)
holds about 94% and “untrue” protein about 6%.
From "true" protein, casein (insoluble protein with coagulating properties) represents
about 82% and the soluble protein (alpha-lact-globulin, beta-lact-albumin, immune globulins,
etc.) represents about 18%.
Casein is a quality protein, in spite of its deficit in sulphur amino acids (methionine and
cystine). Fortunately, lact-albumin and lact-globulin are rich in these amino acids, so the milk
protein (as a whole) has a high biological value (of the order of 85%), indicating high quality.
The milk protein is similar to egg protein, in terms of amino acids content, except the
lower sulphur amino acid content.
Lactose (a carbohydrate) has a smaller variability than fat and protein, ranging from
4.7% in goat’s milk to 5.4% in buffalo’s milk.
Moreover, the lactose content of milk is the most difficult to be changed through feeding
methods.
Lactose (disaccharide consisting in a molecule of glucose and one of galactose) is a
specific compound only of milk. There are also found in milk other carbohydrates (free glucose,
free galactose) in very small quantities.
Although lactose is a disaccharide, it does not taste sweet. There is a substrate used in
the fermentation process of milk through the lactic acid bacteria in order to obtain milk products
(cheese, yogurt, etc.).
In terms of minerals content, whole milk is characterized by a relative high level of Ca
and K, and relatively low level in Na, Fe, Mn and Co.
The level of the minerals in milk depends on other factors, species, breed, stage of
lactation (higher immediately after birth) and on the concentration of feeds in minerals.
 In terms of vitamins, whole milk is a variable source of vitamin A, D and E, depending
on the season, including feeding mode (when using green fodders, the level of these vitamins
in milk is higher). Milk is a good source of thiamine and riboflavin but it contains relatively
small amounts of vitamin B12. Vitamin C is present in relative small amounts and in addition it
is destroyed (at least partially) in contact with the air or during pasteurization.

Milk by-products

After whole milk processing, we can obtain two important by-products, used in animal’s
feeding: skimmed milk and whey.
Skimmed milk
Skimmed milk is the by-product obtained after cream separating from whole milk
(through centrifugation), especially cow's milk. Skimmed milk retains almost all protein and
lactose from whole milk, but the fat content is much lower.
The process of degreasing the whole cow’s milk can be almost complete (skimmed milk
contains 0.2-0.3% fat) or partial (skimmed milk has 1%, 1.5%, 2% fat).
The degreasing process determines energy value of this by-product, which is about 340-
350 kcal/kg in the first case and 450-500 kcal/kg in the last case.
The removal process of the fat (more or less), makes that skimmed milk becoming a
poor source in fat-soluble vitamins, but a more concentrated source in protein and lactose.
Skimmed milk can be used in animal feeding in the dried form (powder), or liquid.
Powder skimmed milk is used as a source of protein (contains about 35% CP in DM),
and essential amino acids in diets of monogastric animals, particularly piglets. Powder skimmed
milk can be part of the structure of compound feeds for this category of pigs up to 10%. Also,
in this form it is the major component of replacing milk for calves.
In liquid form (fresh or sour), skimmed milk is mainly used in pig’s feeding, after
weaning.
Whey
When whole milk is treated with rennet for coagulation in order to produce cheese,
casein precipitates and collects most of the fat and about half of calcium and phosphorus. Serum
remained is called whey or lactoserum, whose main component is lactose.
Whey dry matter content is very low, about 7% (otherwise, except nutrients containing
is a source of water for the animals that consume it).
Quantitatively, whey contains less protein (0.8-1%), but with a higher level of alpha-
lact-globulin and beta-lact-albumin, which means very high protein quality.
Whey has a low energy value and low level of fat-soluble vitamins, calcium and
phosphorus.
Most often whey is used in liquid form (fresh or sour) in pigs’ diets.
 In the fresh (liquid) form is very unstable, which it is presumed to be consumed shortly
after obtaining it. Acidification by fermentation makes it more stable because it decreases pH.
For acidification we can use formic acid.
There is the possibility of dehydration, and in this form (powder) it can be used as a
milk replacer for calves (and for other animals until weaning) or in prestarter compound feed
for piglets.

Animal meals

Animal meals are well known for their very high protein content and of a very good
quality (high levels in essential amino acids and balance between them). Also, in general, they
have a hight content in minerals and vitamins.
Animal meals are intended in particular for monogastric animals, but can also be used
in ruminant’s diets, at least for those with high productive performances.
Although animal meals, originated from slaughterhouse by-products obtained from
mammals, are currently banned in the European Union (after the appearance of mad cow
disease), there are areas in the world where their use is permitted. But it is possible that in the
future this prohibition of their use in Europe to be cancelled, because huge resources of protein
are lost.
In France, for example, there are not consumed by humans about 45% of the cattle and
sheep and about 35% of the pigs and poultry body. These slaughterhouse by-products could be
turned into animals’ meals.
A first step was made in 2013, when the European Commission decided to reuse pigs
and poultry by-products meals in aquaculture, under the name “transformed animal protein".
The main animal meals used worldwide are fish meal, fish protein concentrate, bone
meal, meat meal, blood meal and hydrolysed feather meal.

Fish meal

Fish meal has been used as a feedstuff since the 19th century in Northern Europe and
now it is used worldwide. Global production of fish meal has been stable for the past two
decades, about 5-6 million tons, Peru and Chile being the main producers.
The best quality fish meal is obtained from raw fish. However, in order to prevent
protein and oil breakdown, raw fish is often processed through boiling, pressing, drying,
chilling (mixing fish with ice) or chemical preservation (with sodium nitrite or formaldehyde).
Fish meal, in different varieties, has very high protein content, 60-70% and protein
quality are very good and relatively constant. It is rich in essential amino acids, particularly
lysine and methionine. From this point of view is an ideal mixing component with cereals,
especially maize.
 In fish meal of the highest quality, protein digestibility is 93-95%, but this may decrease
to 60% if processing conditions, particularly the intensity and duration of heat treatments are
not the best. The average fat content is 8-10% but may be lower (stronger degreasing) or higher
(if derived from fatty fish).
Oil from fish has a high content in polyunsaturated fatty acids (PUFA) and optimal
proportion between omega-3 and omega-6 fatty acids.
Fish meal also has a high level of ash (10-15%), predominantly calcium, phosphorus,
sodium and chlorine. Fish meal is a good source of vitamins, particularly B vitamins (such as
vitamin B12 and riboflavin).
It has an extremely favourable influence on the growth of young animals, especially
chickens’ broiler, turkeys’ broiler and piglets, containing a growth factor, generically called
"animal protein factor" (APF).
Fish meal is used mainly in monogastric animal diets for the high content in protein,
essential amino acids, and for favourable effect on growth, through above mentioned APF.
Fish meal may be included in the compound feeds for young belonging to monogastric
animals up to 10%.
In adult monogastric animals, incorporation rate is up to 5%. It is recommended its
removal from the latter part of fattening (for economic reasons, but also not to induce a fishy
meat taste and smell). This possibility must be taken into consideration to be applied to eggs or
milk.
For ruminants, especially for lactating cows with high milk yields, fish meal is used
primarily as a source of non-degradable protein in the rumen and also a source of methionine.
It will be supervised not to exceed 5% in the compound feeds structure.
Fish meal, in improper storage conditions, may become contaminated with some
pathogens, particularly Salmonella. In addition, fat oxidizes easily and appear toxic peroxides
(therefore it is desired a better degreasing). Also, the table salt, which is contained in relatively
large quantities, can cause poisoning of young animals.

Fish protein concentrate

Fish protein concentrate can be prepared from any type of fish or fishery waste.
It is prepared from fish by extracting the oil and settling out the bones and after drying.
The final product has a very high protein content (even 85-90%) and lower content in ash
comparing to fish meal.

Meat-bone meal and meat meal

 Meat-bone meal is a powder obtained by boiling, degreasing, sterilizing and grinding
by-products of slaughterhouse terrestrial animals, which are not suitable for human
consumption.
Among these animal meals are non-edible carcasses, confiscated carcasses, inedible
organs (lungs, spleen, etc.) and bones. Hair, hoofs and blood normally are not included.
There are several types of such by-products, differentiated mainly by the ash content.
If the content in ash is high, it indicates a higher bones proportion and it is really meat-
bone meal. If the level of ash is low, the appropriate term is meat meal.
It is possible for the bones to be completely separated from the meat and then to be
degreased, sterilized and grounded. A part of this is used to obtain bone gelatin (used in human
consumption) and another part to obtain bone meal, an important source of calcium and
phosphorus for the animals.
The protein content of the meat-bone meal is variable, depending on the origin of the
raw material, between 45-60%.
In some countries, where using meat-bone meal is allowed (not in the EU) it is intended
preferentially in pigs and poultry diets, up to 10% of compound feeds structure.
In European Union there can only be used meal derived from healthy meat, like the one
intended for human consumption. It is used as basic ingredient in industrial dry food for dogs
and cats.
On the market exists a particular type of meat-bone meal, namely poultry by-product
meal.
Poultry by-product meal is produced from scraps slaughter of birds (heads, necks,
feet, and intestines) or from laying hens slaughtered after the completion of a full production
cycle and which cannot be sold on the market due to poor quality.
Poultry by-product meal use is prohibited for livestock feeding in the European Union
since 2002, after the approval of Regulation No. 1774.

Blood meal

Blood meal is defined as the <product obtained by drying the blood of warm-blooded
terrestrial animals >.
There are various ways of obtaining blood meal. Basically, after harvesting and adding
a blood anticoagulant it is subjected to drying, sterilization and then grinding. Drying methods
are important because there are an inverse relationship between the amount of heat applied and
protein and amino acids digestibility. This is applicable especially to lysine, to which
digestibility and availability in the body decrease if heat treatments are intensive.
Blood meal is available anywhere in the world, but its use is regulated in some countries
for reasons of food safety, as for other products obtained from animals. Currently, it is not
permitted to be used into the European Union.
 Blood meal (it has the colour of chocolate) is characterized by very high protein content,
about 80%.
It is one of the richest sources of lysine, methionine and leucine, three essential amino
acids. However, it is deficient in isoleucine, which makes its biological value of the protein to
be lower than in the case of fish meal. Blood meal is used in addition to cereal grains, especially
in feeding monogastric animals.
Its palatability is low especially on young animals. Therefore, it is included in limited
proportion in the structure of compound feeds.
In poultry, in the most cases the rate of inclusion in the compound feeds is 2-3% and in
the case of pigs 3-5%.
From blood can be obtained a special product, namely spray-dried blood plasma, used
in particular in the USA in piglets compound feed immediately after weaning.
It demonstrated that its inclusion in piglets’ diets has led to increasing consumption and
weight gain during the first two weeks after weaning.

Hydrolysed feather meal

This animal meal is defined as "the product obtained by hydrolysis, drying and grinding
feathers". The hydrolysis of the feathers is done by treating with steam under pressure (at a
temperature of 140-150° C) and by biological hydrolysis (some bacteria have been identified
that produce a feather digesting enzymes).
Feather meal has high protein content (80% in average), oscillating between 60% and
90%. However, protein quality is more reduced, because it is deficient in lysine and methionine.
The average digestibility of amino acids is about 50% but it can be lower or higher.
Feather meal has a low degree of palatability, so it must be introduced gradually in
rations and in small proportions (2-3% in fattening pigs compound feed’s structure).
As fishmeal, feather meal can easily become contaminated with Salmonella, in improper
storage conditions.

Animal fats

Animal fats have always been produced in large quantities, but they were directed to the
detergent industry. After the appearance of synthetic detergents, the excess fats were directed
to animals feeding, considering their relatively low price.
Fats are differentiated according to the origin, melting point, the amount and range of
fatty acids, colour.
Animal fats are separated as "tallows“, when they remain solid over 40° C, and as
"lards“, when they remain solids between 20° and 40° C.
Generally, "tallows" derived from cattle and sheep, and "lards" from pigs.
 There are also fish oil, fish liver oil, used as energy sources, but mainly as a source of
polyunsaturated fatty acids, vitamin A and vitamin D. These products oxidize very quickly and
require special storage conditions (in tight containers).
Besides the low price, fats have high energy value, given by their caloricity and their
digestibility.
The digestibility of animal fats is about 80% for monogastric animals and about 85%
for ruminants’ animals. Combined and homogenized, digestibility can reach to 90%, reflected
in an energetic nutritional value very high, about 2.7 LFU/kg DM.
In addition, fats placed in compound feeds increase their palatability.
Also, some experiments indicate that in the case of using fats, there are created
opportunities of lowering the amount of faeces in monogastric animals.
Because fats oxidize easily they are stabilized by adding an antioxidant, like EDTA
(ethylene-diamine-tetra-acetic acid).
Stabilization of animal fats, before their inclusion in compound feeds allows keeping
them in good condition for a longer period of time, if in compound feeds there are not placed
mineral premixes.
In ruminants, fats are used in particular in milk replacers for calves and for lambs, 15 -
20% in their structure. There have been many studies on the effects of animal fats in lactating
cows. The results are favourable, but highly variable.
In monogastric animals, especially pigs, more important than quantity it is the type of
the fat used, to reduce "soft fat", given by the degree of saturation of fatty acids. In rations well
balanced in protein, minerals and vitamins, the addition of fat had little effect on fat consistency.
In poultry meat (broiler) diets, using fats is a solution in the very hot areas, because they
have as effect producing a smaller quantity of body heat. Fats added in the proportion of 3-4%
in compound feeds for poultry meat, have also favourable effects on weight gain.
For laying hens, the share of the fats in the compound feeds’ structure depends on the
percentage of laying (the number of eggs produced in a period of time).
When this percentage is high (over than 300 eggs/year), fat can be included up to 5-6%
in compound feeds structure.

Single-cells protein and urea

Single-cells protein
 Proteins obtained from single-cells micro-organisms are an increasingly important
source for animals, at least in certain areas of the world, where classical protein resources are
limited.
This happens because certain micro-organisms can be used to ferment various by-
products and accumulate protein in their own cells.
There are many "materials" that can be a substrate for the development of microbes,
such as: by-products of agricultural crops (wheat straw, rice straw, rice husks, corn cobs), by-
products of food industry (whey, molasses, fruit pulp, tomato pulp), by-products of alcohol
industry, by-products of the wood industry (sulphite residues), manure, etc.
Among unicellular organisms, some yeast (such as Saccharomyces, Torula, Candida)
or some bacteria (such as Pseudonomas) are used for this purpose and they grow very quickly
if certain conditions are met.
Unfortunately, at least at present, the costs of producing such protein sources are high,
but the perspectives are good.
Manufacturing processes include fermentation, filtration, precipitation, coagulation,
and centrifugation (the latter operation is necessary to reduce the water content to keep single-
cells protein in good condition).
The protein content of bacteria is higher than that of yeast (about 50%, compared to
45%, in the dry matter). Bacterial proteins have higher sulphur amino acids content, but lower
lysine content.
Proteins from both types of micro-organisms have high level of nucleic acids (50-150
g/kg DM), which imposes a limitation on their use in monogastric animals diets.
Such sources of protein are usually included in compound feeds (CoF) for animals in
the dry state. In case of pigs, it can hold up to 10% of CoF structure, successfully (partially)
replacing fishmeal.
For poultry (laying or meat) a rate up to 5% is recommended, without affecting egg
production, growth rate or eggs or meat nucleic acid content.
Good results were obtained by using unicellular proteins in ruminants as well, especially
in calves (included in milk replacers), but also in high yielding lactating cows.
In the situation where, using meat meal (obtained from slaughterhouse waste) in the
European Union is prohibited (as well as antibiotics used as growth promoters), the production
of such protein sources (single-cells proteins) is a viable alternative.
At present, it has been possible to fractionate the yeasts into cell walls (which have a
rigid structure) and in cellular content (yeast extract).
Yeast cell walls are already an alternative to the use of antibiotics as growth promoters
(they can block the colonization of pathogens in the digestive tract and together are eliminated
from the body).
 Yeast extract (also used as a source of natural flavours) is a very good source of protein,
by level (over 50% CP in DM), the content in essential amino acids and the content of
nucleotides (these with favourable effects on immunity and tissues regeneration).

Urea

Urea is a synthetic concentrate feed and source of nitrogen for adult ruminants with fully
developed digestive tract. It appears as a white crystalline salt and it is soluble in water.
Urea contains 46% nitrogen, so one kilogram of urea is equivalent to 2875 g crude
protein (460*6.25) or 1472 g IDPN. Ruminants have the ability to use non-protein nitrogen
(such as the one from urea) as a source for synthesis of their own microbial protein.
However, the amount of urea distributed should be limited because it is rapidly
hydrolyzed in the rumen by microbial enzymes (ureases), producing ammonia and carbon
dioxide. Ammonia reaches the maximum concentration in the rumen in 1-4 hours from the
administration of urea (depending on the conditions in the rumen), after which the level begins
to decrease.
Ammoniacal nitrogen is used by micro-organisms for protein synthesis, but if the
concentration exceeds the capacity for recovery by bacteria, ammonia crosses ruminal walls
and reaches the bloodstream. If blood ammonia levels exceed certain limits, it can cause
poisoning, sometimes serious. Part of the ammonia in the blood is again transformed into urea
(in the liver) and eliminated through the urine.
Therefore, urea should be administered in such a way to produce a slow hydrolysis.
Also, beyond the slow release of ammonia in the rumen, through various means it must
be stimulated using it for microbial protein synthesis.
For this, there are recommended the following rules: the use of rations with a minimum
assimilable carbohydrate substrate (required for microbial protein synthesis), providing rations
with an optimal level of “true” protein (consisting in amino acids), providing rations with
enough mineral elements (especially sulphur, involved in proteosynthesis), providing a period
of adaptation to urea (which can be about 2-3 weeks), staging of urea consumption (2-3
times/day) and very good homogenization with basic concentrates feeds.
Most often, urea is incorporated into compound feeds or into concentrates mixtures, up
to 2% of the structure. Sometimes it can also be incorporated into lick blocks, along with
molasses, table salt (NaCl) and starch, but other ingredients (minerals or vitamins) can be
added. The average daily recommended amount of urea (for adult ruminants only) is 20 -30
g/100 kg body weight.
 Compound feeds
Current situation of compound feeds

Compound feeds (CoF) are actually concentrates mixtures of vegetable, animal, micro-
organic, mineral and synthetic origin, dosing so as to form a complete source of nourishment
or a complementary source of nourishment for animals.
Compound feeds, produced in specialized factories, were used in animal feeding since
the early twentieth century (in the USA), but we can speak about a real industry only after the
Second World War.
It is estimated that now, at global level, are manufactured about 1 billion tons CoF/year.
In the last years, worldwide the top three producers of CoF (in million tons per year)
were: China (180), USA (170) and European Union (160), who held together about 50% of the
total world production.
In the European Union, the three major producing countries, in millions tons/year, were
Spain (29), Germany (24) and France (22). Netherlands, Italy and UK recorded (each one) a
production of about 14 million tons. In Poland were produced 9 million tons and in Romania 4
million tons .
Worldwide, about 45% of CoF produced were directed to poultry (meat, eggs), about
27% to pigs, about 20% to ruminants (dairy, meat), 4% to aquaculture, 2% to pet industry, 1%
to horses and 1% to other species.
Compound feeds reduce production costs, ensures efficient animal productions,
guarantee safety of feed and foods, and improve animal health and welfare. CoF can also reduce
the pollution potential through animal manure, because they provide strictly the requirements
of the animals.
In parallel with the development of legislation in the field, in EU there have been
established minimum rules for the production of CoF. Since 1998, the EFMF (European Feed
Manufactures Federation) has established guidelines for the development of national best
practice in the production of CoF, in order to implement food safety systems.

Sources used in compound feeds industry

In the compound feeds industry, there are used different sources (raw materials) and in
a very large number.
In the following, only the part with high resonance will be presented, which will be
grouped into: (a) energy sources, (b) protein sources and (c) additives.
 a. Energy sources

Energy sources which are incorporated into CoF are represented, primarily by cereals.
For the same purpose there can also be used fats (vegetable or animal origin), sugar and
molasses.
Cereals
Cereals (maize, barley, wheat, etc.) are the main components of the CoF as energy
sources mainly, but not only. The use of cereals is prioritised by the nutritional reasons and by
their availability on the market.
The share of participation of cereals in CoF structure is determined by their nutritional
and healthy values, by the combination among them and by the type of animals that consume
CoF. So, the limits are very large, from 40 to 80%.
Globally (worldwide), the percentage of inclusion of cereals in CoF is about 50%, with
a rising trend in recent years. Follow in this respect, oilseeds by-products meals (about 30%),
and the difference (about 20%) is covered from other sources.
The cereals from CoF composition must meet certain quality conditions, relating in
particular to maturity (linked to the water content) and fungal contamination level.
An insufficient degree of maturity (over 13-14% water), in addition to the lower content
in nutrients and lower quality, means additional costs for drying and the risk of development of
the mold.
The molds, those that produce mycotoxins, belong in particular to the types of
Aspergillus, Penicillium and Fusarium, and they develop on cereals in the field, during
harvesting, storage and processing.
The main mycotoxins which can contaminate the cereals (and other feeds) are aflatoxin
(B1, B2, G1, G2), zearalenone, ochratoxin and fumonizin (B1, B2).
Consumed by animals, mycotoxins are eliminated through urine and faeces (the most
part), but a proportion of them remains in the tissues of animals, including milk.
Mycotoxin’s toxicity is manifested generally in chronic disorders forms (which in the
case of animals affect productivity), death being rarely recorded.
It is therefore necessary to know the content of cereals in mycotoxins and which
measures to be taken: their removal from manufacturing, mixing with other healthy cereals or
using mycotoxins binders.
Globally (worldwide) mycotoxins have a significant impact on the profitability of
livestock and animal products safety.
Despite of the efforts to control fungal contamination of feeds and foods, the incidence
on human and animal health is very high.
In this respect, the main challenges for the future include:
* increasing the number of mycotoxins analysed (and their metabolites);
 * improving knowledge on toxicological effects of mycotoxins;
* more correct evaluation of the risks of mycotoxins and their metabolites on insurance
maximum protection for human and animal health.
Fats
In certain situations, for achieving high energy levels in CoF, as energy sources there
are also used animal and vegetable fats. This happens, for example, in the case of using CoF
for chickens broiler and piglets, but not only.
As fat sources there can be used lards, tallows, soybean oil, sunflower oil, etc. We
should pay a particular attention to storage these fats, because oxidize easily and affects the
health of animals and quality of livestock products.
Sugar and molasses
Sugar and molasses can also be used as energy sources, in certain circumstances. Sugar
is used in the CoF of the piglets to increase consumption. Molasses is used for its good energy
value, but also as a binder for producing granulated (pelleted) CoF.

b. Protein sources

The protein level targeted in CoF is achieved mainly through participation in their
structure of sources of vegetable and animal origin. The micro-organic origin products presence
should be less visible.
Vegetable protein sources
The main sources of vegetable protein are meals, by-products from the oil industry
(soybean meal, sunflower meal, rapeseed meal, etc).
Other sources of vegetable protein are used on a smaller scale (peas, full-fat soya, wheat
bran, alfalfa meal, etc).
Soybean meal has always been and it still remains the most important source of
vegetable protein in CoF industry.
Soybean meal can be used without nutritional restrictions, up to the protein requested
level in CoF, with the condition to cover the requested methionine level.
Soybean meal can reach up to 30-40% in the structure of CoF in monogastric animals
meals.
However, worldwide almost half of it comes from genetically modified soybean.
For soybean meal, the quality conditions (among other things) provide maximum 10%
water and minimum 38% crude protein.
Full-fat soya is obtained by processing whole soybean, by mechanical and thermal
processes (the latter for inactivation anti-nutritionally factors).
It is incorporated in particular in CoF for young monogastric animals, as a source of
protein (and amino acids), but also as an energy source.
 Sunflower meal is used limited in CoF for monogastric animals, due to its high content
in crude fibre. The limits go up to 10% for adult birds and up to 15% for adult pigs (smaller
rates in young animals and birds).
Rapeseed meal is a source of protein for animals. Its production increased lately. This
applies especially in Europe in last years, where the rapeseed is used in production of biodiesel.
Rapeseed meal derived from classical varieties, with a high content in glucosinolates
and erucic acid, is used strictly limited in CoF structure.
The varieties derived from the "double-zero“rapeseed (Canola) may be included in a
higher proportion in the CoF and it can replace up to 50% of the soybean meal.
Peas represent a notable source of protein in Europe and there are regarded (as rapeseed
meal) as an alternative to soybean meal.
Peas have high lysine content, but lower content in methionine and cystine (just as
soybean meal). The peas - rapeseed meal combination can be considered beneficial.
Wheat bran and alfalfa meal are other sources of vegetable protein used when they are
available, especially in the production of compound feeds for herbivores (ruminants, horses,
rabbits).
It can be included also in compound feeds for monogastric animals (especially for
pregnant sows, to regulate digestive transit), but limited due to higher content in crude fibre.
Animal protein sources
The animal sources of protein that are worth remembering we mention, animals meals
(fish meal, fish protein concentrate, etc.) and skimmed powder milk.
Animals meals are used to balance the protein level of CoF, designed especially to pigs
and poultry, but also for extremely favourable influence on the process of growth in young
animals. In terms of quality, it must be given special attention to animal meals (water and
protein content, bacteriological contamination, degree of rancidity of fats).
Skimmed powder milk is the basic constituent of milk replacers for calves (and for
young specimens belonging to other species of animals). It is recommended to be included in
the “prestarter” CoF intended to piglets.
Micro-organic protein sources
The most common protein sources of micro-organic origin are fodder yeast.
Under the banning on the use in the European Union of meat meal obtained from
slaughterhouse residues and antibiotics as growth promoters, the production of fodder yeast (in
dehydrated form) is a viable alternative.
Dried fodder yeast is commonly used in compound feeds of monogastric animals (3-5%
of their structure), both as sources of protein and sources of vitamin B complex. From a
qualitative point of view, fodder yeast should have less than 10% water and at least 45% crude
protein.
 c. Additives

Additives are introduced into CoF for the following possible functions: favourably
influence nutritionally and sanitary values, stability, productivity of animals, reduce the impact
of animal feeding on environmental pollution, have a beneficial influence on animal welfare
(by modifying the gastrointestinal flora and preventing the occurrence of diseases).
Under Regulation 1831/2003, only additives that have been authorized by the European
Food Safety Authority (EFSA) may be placed on the market and only for the use specified in
the authorization. In the same time, since 2012 European Food Safety Authority imposed also
the safety of additives.
Additives can be classified as follows:
- nutritional additives (minerals, vitamins, enzymes, amino acids, etc.);
- zootechnical additives (digestibility enhancers, gut flora stabilizers);
- technological additives (preservatives, antioxidants, emulsifiers, stabilizers, acidity
regulators);
- sensory additives (flavours, etc.);
- coccidiostats and histomonostats (additives for poultry, for health reasons).
The main additives which can be inserted into the CoF will be presented below, in the
following order: minerals, vitamins, enzymes, amino acids, antibiotics, metabolic modifiers,
probiotics, prebiotics and mycotoxin binders.

Minerals
Most feeds of vegetable and animal origin cannot cover mineral requirements of the
animals, especially in intensive systems.
Therefore, in CoF should be included also mineral sources (inorganic origin, or organic
origin).
The best-known inorganic sources of minerals are carbonates (e.g., calcium carbonate),
phosphates (e.g., mono-calcium phosphate, di-calcium phosphate and tri-calcium phosphate),
chlorides (e.g., sodium chloride), sulphates (e.g., iron sulphate, copper sulphate), oxides (e.g.,
iron oxide, manganese oxide).
The problem is that the inorganic minerals may interact in the gastrointestinal tract, with
cellulose, tannins, oxalates, other substances and it results a decreasing of the degree of their
absorbability in the body.
Therefore, it is preferable to use organic minerals, chelated minerals. When the
minerals are connected to chelating agents, such as amino acids or some proteins, they are more
stable and less reactive in the digestive tract, leading to increasing their availability in the body.
Organic minerals can be included in the CoF at lower levels comparing to inorganic
minerals and there are found in lower concentrations in the faces and urine, having a positive
effect on the environment.
 Because organic minerals are more expensive, they can be used in combination with
inorganic minerals. The best-known organic minerals and their forms are: iron (iron-proteinate),
copper (copper-lysine complex), zinc (zinc-proteinate) and selenium (seleno-methionine).

Vitamins
Compound feeds include in their composition also vitamin supplements. It is absolutely
normal because their price is relatively low comparing to the cases when we have a deficiency.
Moreover, there are used higher doses of vitamins, above the strict animal requirements, set in
experimental conditions.
There are three main processes to produce supplement vitamins: through chemical
synthesis, fermentation and extraction from vegetable or animal sources.
The vitamins used in animal feeding are produced almost exclusively using the first two
methods. The chemical synthesis is based typically on the use of raw materials, such as crude
oil or gas. These materials are subjected to multi-step recombination, to form the desired
vitamin.
Even if chemical synthesis is currently the main source of production, vitamins obtained
through fermentation are expected to become increasingly important, being a natural way.
There are some micro-organisms capable of producing vitamins during the fermentation
process, after which they are separated and purified.
Vitamins are sold in different forms, which vary according to their concentration,
stability, solubility, and resistance during subsequent processing.
Vitamins are incorporated into the CoF in the form of vitamin premixes, or vitamin -
mineral premixes. Such premixes have about six months terms of validity and they are found
between 0.2% and 1% in compound feeds structure.

Enzymes
Not all feed’s components are degraded totally by the animal’s body enzymes, so some
nutrients become unavailable. Therefore, there are used enzymes supplements in the diets.
Thanks to advances in biotechnology, enzymes can be produced today in large
quantities and at reasonable prices, so belonging to CoF has become a common thing.
The beneficial effects of using enzymes (as additives) can be summarized as follows:
improve the efficiency of the use of feed’s components in the body, increasing digestion and
absorption, contributes to reducing the amount of manure and implicitly environmental
pollution, helps to maintain the "health" of the digestive tract, limiting the possibility of
developing disease-producing bacteria.
Enzymes are used as additives especially for monogastric animals, but also for
ruminants.
Cereals and other concentrate feeds contain large amounts of soluble non-starch
polysaccharides (NSPs), which form viscous gels in the presence of water. Major adverse
effects of non-starch polysaccharides (NSPs) result from their ability to increase digesta
viscosity in the gastrointestinal tract, impair the digestion and absorption of nutrients, and
interact with the gut micro-flora to alter the morphology and function of the digestive system.
In this respect, commercial enzyme products, which are used for poultry and pigs
feeding, are added to barley, oat, peas, rye, or wheat-based diets.
The enzymes used in non-ruminant diets (CoF) include: β-glucanases, pentosanases,
phytases, a mixture of all these enzymes, a mixture of proteases, and a mixture of carbohydrases
and proteases.
In contrast, in ruminant diets there are generally included carbohydrates, consisting into
cellulases and hemicellulases.

Amino acids
For covering the whole requirement of protein and in amino acids for some categories
of monogastric animals, there are used also expensive sources of feeds, such as fish meal. There
is an alternative by using lower levels of protein, but in combination with amino acids
supplements (synthetic amino acids).
In this situation, decreases the amount of protein consumed, increases the efficiency of
its use in the body and it is eliminated less nitrogen through the faeces and urine.
Synthetic amino acids are stable during the production of CoF and storage, and do not
interact with other nutrients, such as micro-minerals.
Amino acids (AAs) are produced on an industrial scale by chemical or microbiological
(fermentation) processes. Crystalline AAs (e.g., L-lysine, DL-methionine, L-threonine, L-
tryptophan), also arginine, glutamine, glycine have been supplemented to non-ruminant diets to
improve protein deposit, intestinal integrity, immune function, and growth performance.
In the categories of ruminants with high productive performances, such as milking cows,
the first limiting amino acid is methionine, then lysine, and in this case there can be used both
synthetic amino acids (DL-methionine and L-lysine). To increase the flow of synthetic
methionine and lysine to the small intestine of ruminants it is necessary the protection of the
rumen.

Antibiotics
Antibiotics (enhancers of feed efficiency) were first used as additives in diets for
chickens and pigs in the 1940s and 1950s.
This class of compounds includes antibiotics which are naturally produced by yeasts,
mold, and other micro-organisms and chemotherapeutics, which are chemically synthesized.
The therapeutic doses of antibiotics (at higher levels) are administered to animals by
injection, in feeds or in water, for the treatment of diseases caused by bacteria.
 In subtherapeutic doses (at smaller levels), antibiotics are incorporated into CoF (as
growth promoters) to improve animal growth rate and feed efficiency (they stop the
development of pathogenic bacteria in the digestive tract).
Antibiotics as growth promoters have been used with good results, especially in pigs,
poultry and pre-ruminant calves, in amounts ranging from 20 to 40 mg / kg CoF.
There are voices that sustain the idea that, although there are used in small doses, they
would increase the resistance of bacteria to antibiotics and when they will be used for
therapeutic purposes, they have no effect and diseases would become untreatable.
Therefore, since 2013, the use of antibiotics as growth promoters, is totally banned in
the EU (the last that were allowed were avilamycin and flavomycin).
The ban was dictated by consumers’ pressure, but the antimicrobial resistance
transferred from animals’ products to humans was not epidemiologically confirmed.
Worldwide, antimicrobial agents played and play an important part in the efficient
production of pork, beef, poultry meat, and other animal products.

Metabolic modifiers
Metabolic modifiers, starting with growth hormones (such as bovine somatotropin and
pig somatotropin), can be used as additives to increase the amount of meat and reduce the
amount of fat deposited in the body.
Possible adverse effects on heart and carcinogen potential imposed the prohibition of
their use many years ago in the European Union, but not in other countries of the world.
Stopping the use of metabolic modifiers, as growth promoters, in the European Union
had important consequences on animal’s feeding and the profitability of their growth, because
other substances have been enforced, which are more expensive.

Probiotics
Probiotics are dietary supplements containing beneficial live bacteria or yeasts that confer
health to the gut flora and the host.
In monogastric animals, strains of Lactobacillus, and Streptococcus are used for this
purpose, maintaining the intestinal microbial ecosystem and mucosal integrity. In addition to
stimulating the development of the desired micro-organisms, probiotics destroy some
pathogenic germs.
In ruminants, using the yeast Saccharomyces, in living or lyophilized form, has
beneficial effect on rumen fermentation.
In terms of prohibition antibiotics in EU, as growth promoters, the use of probiotics as
antimicrobial agents has gained a higher relevance.

Prebiotics
Prebiotics can be defined as ingredients that are not digested by animal enzymes, but
they can beneficially affect the host by selectively stimulating the growth and/or activity of
one or a limited number of the bacterial species in the small and large intestines.
Oligosaccharides, like fructo-oligosaccharides and mannan-oligosaccharide (MOS), are
commonly used as prebiotics for livestock species, and humans.
Dietary supplementation with MOS reduced the incidence of diarrhoea on weanling
piglets and enhanced their growth performance.
Similarly, adding MOS to the diets of young chickens inhibited the growth of intestinal
pathogenic bacteria, improved immune status, and increased the density of small-intestinal
microvilli.

Mycotoxin binders
Mycotoxins are secondary metabolites produced by the fungal (such as Aspergillus,
Penicillium, and Fusarium). Mycotoxins are distributed widely throughout the world and they
are activated in different environmental conditions.
Contamination of feeds with mycotoxins may occur during the harvesting, drying, and
storage processes, but the risk contamination increases under high temperature and moisture
conditions.
Methods for protecting animals from the toxic effects of mycotoxins include grains testing,
use of mold inhibitors, microbial inactivation, physical separation, thermal inactivation, irradiation,
ozonation, dilution, and use of binders.
Binders (adsorbents) have been used as one of the best and most practical way, because
they are relatively inexpensive, generally known for being safe, and they can be easily added to
animal feeds.
Adsorbents added to aflatoxin-contaminated feeds can bind the aflatoxin during the
digestive process and they can manage the toxin to be excreted safely from the animal body.
Possible adsorbent materials that have been studied include silicate minerals, activated
carbons, complex indigestible carbohydrates (e.g., polysaccharides from the cell walls of yeast),
bacteria, and synthetic polymers.
Obviously, there are other additives such as: organic acids, preservatives, flavouring
substances, antioxidants and others.

Compound feeds classification

Compound feeds (CoF) can be divided into: complete and complementary compound
feeds.

Complete compound feeds

Complete CoF are used primarily in intensive systems of raising pigs and poultry, but
also for other animals: rabbits, fish, even horses.
 Complete CoF contain all the nutrients which animals need to cover their requirements.
Depending on the age of the animals, complete CoF can be delimited in: prestarter,
starter, grower and finisher.
Prestarter CoF is produced for young animals in the first days after birth or hatching.
Such CoF are characterized by a high content of nutrients. For example, the prestarter
CoF for broiler turkey has 26-27% crude protein, and prestarter CoF for piglets has 3300 kcal
ME/kg, values never met in other categories of farm animals.
Starter CoF replaces prestarter CoF and it is designed to the next age categories of
animals. Their structure is similar to prestarter CoF, but with a lower level of nutritionally
parameters.
Grower and finisher CoF are intended for animals in the last periods of growing and
finishing. In relative terms, they have lower protein and higher energy content.
Special types of CoF are milk replacers, intended to replace maternal milk for young
animals, especially calves.
The milk replacers through their composition attempt to reconstruct the whole milk.
Their main component is powder skimmed milk, eventually dehydrated whey (both hold 65-
70%), completed by some protein sources (of animal and vegetable origin), animal and
vegetable fats (emulsified and stabilized) and various additives. Complete CoF should be
accompanied by documents containing necessary data (Regulation EC No. 767/2009).

Complementary compound feeds

The complementary CoF are produced for economically reasons and contain mainly
protein sources and additives (including vitamins and minerals).
Farmers buy complementary CoF and mix them with cereals (energy sources), obtained
on their own farms, reconstructing a complete CoF.
In the final mixture, complementary CoF hold between 5% and 40% (difference up to
100% will be represented by cereals). Participation rate of complementary CoF depends on
their concentration in nutrients and remitted categories of animals.
 Feeding cattle

Feed’s utilization particularities by cattle

Cattle, ruminants’ animals, have adapted digestive system during evolution (functional
and anatomical) to the use of fibrous plant material, which gives them an advantage comparing
to monogastric animals.
Cattle have several features of feed’s utilization, different from those found in other
species, due to capacity and conformation of digestive tract, on one hand, and specific of
digestion, on the other hand.
Thus, the great capacity of the digestive tract allows the cattle to consume large amounts
of volume feeds, sometimes exclusively.
Digestion features are consequences of the action of microbial flora, present mainly in
the rumen, reflected in many degradation and synthesis processes, through which cattle can
provide themselves a large part of the nutrients needed.
Microbial digestion is a major physiological process, determining ultimately the degree
of utilization of feed’s constituents in the body.
Synergism and antagonism between different groups of microbes (bacteria, protozoa)
are transmitted on the host animal, to assimilate as much as possible feed’s components.
Digestion processes that occur in the rumen (and not only) include all organic
substances found in feeds (carbohydrates, proteins, lipids, etc.).
Carbohydrates digestion
Due to microbial enzymes, all intracellular carbohydrates can be fermented, hydrolysed,
and they will constitute the energy required for rumen micro-organisms on their activity.
Soluble carbohydrates (glucose, fructose, sucrose) are fully hydrolysed (in various
ways).
Starch is hydrolysed almost completely in the rumen, almost 95%, but the real values
depend on the nature of the feeds (e.g., maize and sorghum starch is degraded less than barley
and wheat starch).
Other carbohydrates, like cellulose and hemicellulose, are subjected to a slow and partial
hydrolysis.
Lignin is practically not digested. In addition, it has a negative effect on the degradation
of other constituents, inhibiting enzymatic activity.
Digestion of carbohydrates requires a whole series of reactions and a large number of
intermediate compounds, ending in a mixture of volatile fatty acids (VFA), like acetic acid,
propionic acid, butyric acid, etc.
 In the case of regular (classical) rations used in cattle feeding (with optimal ratios
between volume feeds and concentrate feeds), acetic acid represents 60-70% of the total mixture
of VFA, propionic acid about 15-20%, and butyric acid about 10-15%.
The remaining (2-5%) is represented by some VFA less important (iso-butyric, metil-
butyric, valerianic, iso-valerianic).
However, ruminants can be fed with a variety of rations, in which case the amount and
the share of VFA produced differs from that presented for classical rations.
Using rations based on fibrous feeds (hays, straws) with a high content of crude fiber
(CF), leads to increasing the share of acetic acid, compared to other VFA, while the
administration of rations dominated by concentrate feeds (less content in CF), leads to
increasing propionic acid and butyric acid share.
For cattle, as well as for all ruminants, VFA represents the main energy source, in
average 60-80% of the total energy absorbed. The difference (until 100%) is covered by the
energy originating from amino acids (15-20%), long chain fatty acids (5-10%) and glucose (1-
5%).
The carbohydrates fermentation also leads to gases, such as: carbon dioxide (CO2) or
methane (CH4).
Protein digestion
Protein digestion in the rumen is carried out in the form of hydrolysis processes,
decreasing the length of the peptides chain to the point of free amino acids and their
fermentation later, with production of ammonia (NH3), the most important terminal product,
and carbon dioxide (CO2).
The process of protein hydrolysis is more or less intense or fast.
Microbial degradation is rapid and total for the constituents based on non-protein
nitrogen (urea, for example) and for simple protein (free amino acids). For the constituents
structured on protein nitrogen (bound amino acids) the process is slower and partial, so that a
part escapes from ruminal degradation.
Ammonia produced follows two pathways: can be used to synthesize bacterial proteins
(bacterial proteosynthesis) or is absorbed on ruminal walls level.
Absorbed ammonia passes into the blood, it is directed to the liver and it is transformed
into urea, which is partly eliminated through the urine, but it remains a part that is recycled by
saliva.
Actually, all absorbed substances are ultimately found in the blood, either directly or
through the lymph.
Amino acids produced in the rumen pass into the bacterial cells (forming their own
protein) or reach the small intestine (the place where are absorbed).

Lipid digestion
 Lipid digestion in the rumen occurs as two major processes: lipolysis and bio-
hydrogenation.
Lipolysis (the hydrolysis of the lipids) ends with the production of fatty acids. Fatty
acids released (only partially) are not absorbed in the rumen, but will pass in the small intestine,
the principal place of absorption.
Bio-hydrogenation occurs in the rumen as a result of bacterial activity and consists in
the transformation of un-saturated fatty acids (UFA) into saturated fatty acids (SFA), so that
the profile of fatty acid which reaches in the small intestine is very different from that one found
in the feeds.
This fact has 2 sides. The good side is that large quantities of UFA have a toxic effect
on rumen bacteria, and the bad side is that after bio-hydrogenation in milk or in meat will be
smaller amounts of UFA, especially poly-unsaturated fatty acids (PUFA).
Therefore, through the activity of microbial populations occurs a change of UFA profile,
by hydrogenating of double bonds.
Thus, UFA with 18 carbon atoms, such as oleic, linoleic and linolenic acid (with 1, 2
and 3 double bonds) are converted into stearic acid (SFA), which will be deposited in body fat,
as the main fatty acid.
A special feature of feed’s utilization is found in early life calves, as long as rumen is
under-developed and they eat only liquid feeds (milk or milk replacer).
At this stage of pre-ruminant, liquid feeds induce the reflex of closing esophageal gutter
and passes directly in the stomach (avoiding rumen). When the solid feeds are consumed, they
go into the rumen, allowing developing and diversification of the microbial flora.

Feeding bulls

The feeding mode of the bulls has a decisive contribution to keeping these animals in a
breeding condition for long time and the quality of their semen which is produced.
Regarding feeding strategy, there are differences between young bulls (those that have
not completed the growth process) and adult bulls (which got at somatic maturity).
Young bulls intended for breeding should receive a relatively higher amount of feeds
(in relation to body weight) and better quality feeds, to ensure expression of the full potential
of growth until the first mating.
After reaching maturity, feeding level is reduced (also in relation to body weight), not
to risk the appearance of excessive fattening of animals and changing sexual behaviour.
But, strictly quantitative assessment of feeds is not enough for young or adult bulls,
because they have specific requirements in certain nutrients.
 For example, young bulls comparing to adult bulls require a higher percentage of protein
in the dry matter of rations. This is necessary to the development of muscle tissues and limiting
fat deposits.
Moreover, a problem that has been discussed in recent years is related to protein level
in adult bull’s rations. The idea, which is now promoted, with reference to adult bulls, is that
they require a lower amount of protein comparing to several years ago.
Latest data in this case recommends a total protein requirement (maintenance +
breeding) of 70-75 g IDP/100 kg BW or 75-80 g IDP/LFU or 13-14% CP in the ration’s DM.
In addition to providing total protein, is considered essential another aspect, namely the
report (ratio) between rumen degradable protein (RDP) and rumen un-degradable protein
(RUP) in the rations.
Bulls have higher requirements of some vitamins and minerals (compared to other cattle
categories). Thus, the requirement for vitamin A and some trace minerals (manganese, iodine,
selenium, zinc) is relatively higher, thanks to the implications of these nutrients in semen
production and quality.
Therefore, to ensure diets of enough amounts and high quality, the following aspects
can be recommended:
- increasing energy requirement for maintenance in the case of adult bulls up to 10%,
so the feeding level has to be until 1.1“m”;
- ensuring optimum relationship between RDP and RUP;
- limiting in the ration’s structure of volume feeds, up to 60-70% (by reference to DM);
- avoiding use in rations of some feeds of poor quality, such as some fresh vegetable
by-products, rapeseed meal from classically varieties, etc.;
- introduction in rations of vitamin and mineral premixes, with an addition of vitamins
A, D and E and minerals Ca, P, Zn, Mn, Co and Se.
Feeding in the winter
In the winter, the basic bull’s volume feeds are represented by hays, in average amount
of 3-7 kg DM/head/day.
Along with hays, as volume feeds are recommended carrots, fodder beet, perennial
grasses silages, the average amount of 2-4 kg DM/head/day. It is not recommended to use
perennial leguminous silages (alfalfa, clover) in rations for possible abnormal ruminal
fermentations.
Bull’s winter rations include mandatory concentrate feeds (3-5 kg DM/head/day). It
cannot be omitted the oat, considered specific feed. There are other concentrates that can be
used: barley, maize, peas, soya bean meal, sunflower meal, etc.
Feeding in the summer
Green fodders are the basic volume feeds, administered either directly by grazing (near
shelters), or mowed (preferably pre-wilted), in indicative amounts of 3-7 kg DM/head/day.
 Also, there are recommended as volume feeds the hays, in quantities of 2-4 kg
DM/head/day. The reason of completing the deficit in dry matter (DM), specific of summer
rations is to avoid digestive disorders and providing enough degree of satiety, beyond their
contribution in nutrients.
In summer in the rations of bulls are also included compulsory concentrate feeds,
average amount of 3-5 kg DM/head/day.
These recommended types and quantities of feeds are references, ultimately depending
on the characteristics of each animal (every bull is treated individually in terms of feeding
mode).

Feeding cows

At the beginning, references will be made to the feeding cows in the dry period, then to
the feeding cows during lactation period.

Feeding cows in dry period

During the dry period (last 2 months of gestation) cows are fed in a special manner, to
cover the requirements correctly, to maintain a good health, to avoid problems that occur at
parturition, and due to the implications on the first period of lactation.
Dry period has three distinct phases, in which we must have a separate feeding approach.
The first week of dry period
The main problem of this phase is to reduce the milk production until suppression. But
the cows will still be milked in this period, because if the milk is not removed from the udder
determines the risk of occurrence of mastitis (inflammation of breast tissue).
The only solution is feeding mode, by complete elimination of concentrate feeds from
the rations and using lower quality volume feeds.
Until the last 3 weeks of dry period
From this phase we should pay a particular attention to the energy level of the rations.
If cows have a corresponding physical status (good body condition scores), they are fed
with rations with relatively low level of energy.
If cows have poor body status, the energy level of the rations must be increased, within
the specific limits of non-milking cows.
In the last 3 weeks of dry period
It is important at this moment for cows to accommodate with feeding mode that will be
practiced after calving (based on the use of large quantities of concentrates).
There were a lot of discussions about the level of concentrates in the cows’ rations in
the last 3 weeks of dry period.
 One thing is clear, a certain level of concentrates (but not un-controlled) must be ensured
for at least three reasons:
- the volume of abdominal cavity decreases, as a result of foetal development;
- in this time (last 3 weeks of dry period) animals must accumulate body reserves, that
will be used in the first part of lactation;
- in the first part of lactation cows will consume large amounts of concentrates, until the
first days after calving, which involves ensuring continuity in feeding mode to avoid any
digestive disorders.
Finally, specialists agreed that from the last two month of dry period, in the last 3 weeks
the cows must be treated very special.
It appeared a new term "steaming up", which refers to the feeding of the cows in the last
three weeks of pregnancy with relative larger quantities of concentrates.
However, using a lot of concentrates in this period, can lead to excessive fattening of
animals (with negative consequences for calving), decreases ruminal motility, and the
appearance after calving of "fat cow syndrome" or “udder edema”.
In addition to the concentrates the feeds volume has great importance, this means that
they should be in adequate amounts, of good quality and they have to be as those that will be
used after calving.
Feeding in the winter
Hays are considered absolutely necessary during wintertime for cows in dry period, in
indicative amounts of 2-3 kg DM/head/day.
Silages and roots are included in winter rations in average quantities of 2-3 kg
DM/head/day.
There were a lot of opinions in terms of using silages in cow’s rations in late pregnancy.
Today it seems that things are clear: if the silages are good quality they can be used without
problems, if are poor quality they should be excluded from rations.
Feeding in the summer
Green fodders are basic components of rations during summertime of cows in dry
period, average amounts of 4-6 kg DM/head/day.
If there are possibilities for grazing it is recommended this fact, because movement
allows easier calving, although there are difficulties in predicting the amount which be
consumed, due to the rapid modification of the chemical composition and nutritional values of
pastures.
It is possible that some of the green fodders (in equivalent DM) to be replaced by hays,
if they are available, these having a positive effect on the rumen fermentations.
Concentrates are use in both seasons in rations, 2-4 kg DM/head/day, depending on the
milk production potential after calving.
 Feeding cows during lactation

There are significant differences between feeding cows with normal milk production
and cows with very high milk yields, between cows after first calving (primiparous cows) and
cows with more than two calvings (multiparous cows).
Below there will be presented aspects related to feeding dairy cows with normal milk
production and those with very high milk yields, but also there will be references between the
first part of lactation and the second part of the lactation, between primiparous and multiparous
cows.

Feeding cows with normal milk production

Feeding dairy cows in the first part of lactation

In the first 8-10 weeks after calving, feeding cows must be done very carefully.
Besides the fact that cows have a low intake capacity (below requirements), making
animals to mobilize some of body reserves (to support part of the milk production), we must
balance the feeding mode in this period because this influences milk production throughout the
entire lactation.
Therefore, in the first part of lactation cows must be fed at a high level, as high as
possible, in connection with their intake capacity.
The solution consists in using feeds with high energy concentration, both concentrate
feeds (maize, vegetable, or animal fats, etc.), as well as volume feeds (quality maize silage,
etc.).
In the first part of lactation is important to pay attention to concentrate feeds, this
signifying to contain higher proportion of non-degradable protein in the rumen, such as soybean
meal.
Feeding dairy cows in the second part of lactation
Starting with the middle lactation (8-10 weeks after calving) cows can adjust their intake
capacity, being able to cover the requirements.
In this phase of lactation, we must enhance the feeding levels, which allow expression
of the full productive potential of cows (profitability comes from high milk yields).
Feeding primiparous and multiparous dairy cows
If there are differences between feeding cows during a single lactation, there are some
particularities in relation to feeding primiparous cows and multiparous cows.
In primiparous cows, vs. multiparous cows, these features are mainly induced by the
lower body reserves and the less intake capacity. Consequently, it will change the feeding
scheme, by using volume feeds into rations with a higher energy concentration and additional
concentrate feeds.
 It should be noticed also that primiparous cows are more sensitive to digestive and
metabolic disorders, compared to multiparous cows, and any errors in feeding will delay the
next fertilization.
Strategies of feeding lactating cows
The most important strategy concerns the level of concentrates in rations.
In this respect, it is required progressively to move from the smaller amount of
concentrates distributed immediately after calving to the large amounts given when the
maximum milk yield is reached (between the 3rd and 4th week of lactation in multiparous cows
and between 7th and 8th lactation weeks in primiparous cows.
For multiparous cows with about 20-30 kg milk/day (a normal milk production) the
following rules are recommended:
- after calving, during the first three days of lactation, the same amount of concentrate
feeds is administered, like in the last three weeks of gestation (2-4 kg DM/head/day);
- next, until the end of the 4th week of lactation, the amount of concentrates increases
by about 1 kg DM/head/week;
- until the 12th lactation week, the amount of concentrates decreases progressively,
reaching about 90% of the quantity distributed to the maximum milk yield;
- afterwards, the amount of concentrates administered decreases more clearly to be
completely suppressed around the weaning.
For primiparous cows the recommended rules are different.
As can be seen, the amounts of concentrates distributed daily to cows are depending on
the level of milk production.
Certain limits of concentrates cannot be exceeded, to avoid the occurrence of some
healthy problems, at the rumen level. That is why the ratio between concentrate feeds and
volume feeds in rations (c/v %) must also be considered.
Such aspects are presented in the Table 32, to which was added the situation from the
last 3 weeks of gestation. The recommended amounts of concentrates are optional and may be
higher or lower, depending on the quality of the volume feeds.
Along with the concentrates, the rations of lactating cows include volume feeds,
obviously. Their share in the structure of rations decreases as the level of milk production
increases.
In the winter, basic rations of lactating cows consist in hays, silages and roots.
Hays can be administered in different quantities, 3-10 kg DM/head/day; this depends on
the share of silages and roots in the rations structure and their availability for farmers.
At a low milk production level there can be included also straws in rations, up to the
maximum intake capacity.
Among the most used silage there is maize silage and from roots there is fodder beet.
Alone or together, these enter the rations in average amounts of 6-8 kg DM/head/day.
 In the summer, green fodders are recommended in average amounts of 10-14 kg
DM/head/day, for cows with average weights.
Virtually there can be used all known green fodders. Grazing is recommended, the
condition being that pastures should be located near the farm.
The progressive passing of cows from winter rations to summer rations has a very
important role in avoiding undesirable aspects (digestive disorders).
Preventively, it is recommended that to the maximum quantities of green fodders
consumed to be added gradually, alongside with green fodders, a portion of fibrous feeds (hays
or straws) including in the rations in the first days of administration.

Table 32 - Recommended amounts of concentrates for cows (kg DM/day)

During last 3 weeks of pregnancy

Milk production potential Weeks before calving
(kg/day) after calving -3 -2 -1
5-10 0 1 2
10-15 1 2 3
15-20 2 2 3
Over 20 2 3 4
During lactation
Maximum share of
Milk production
Concentrates concentrates
level (kg/day)
in rations DM (%)
Under 10 0 -
15 2-3 30
20 4-5 35
25 6-7 40
30 9-10 45
40 12-13 50

Feeding cows with very high milk production

High producing milk cows (over 30 kg of milk/day) require special conditions of

feeding, because physiological processes are more intense.
The period before calving (dry period) plays an important role on the performances of
high yielding cows in future lactation.
In the dry period it is recommended that, the high yielding cows to be fed with the same
feeds as in the first lactation stage. Also, in the last 3 weeks of pregnancy it is recommended
that concentrate feeds to be placed into rations in relatively large amounts, however, they should
not exceed 1% of the body weight (with reference to high yielding dairy cows).
Using excessive amounts of concentrates in late gestation (dry period) predispose
animals to placental retention or over-fattening.
A specific problem of high yielding cows in early lactation is linked to the appearance
of healthy problems, such as: "fat cow syndrome", "milk fever“ and ruminal acidosis.
Very briefly, “fat cow syndrome” (ketosis, acetonaemia) is associated with an
inadequate supply of the nutrients necessary for the normal carbohydrates and fat metabolism.
The excessive ketone bodies in the bloodstream come from the breakdown of the fat when the
animal is forced to draw on its bodily reserves for energy.
The main symptoms of ketosis are decreased milk production, disturbed eating
behaviour, digestive disorders, muscle spasms and the smell of acetone of milk and urine.
Prevention of ketosis consists in distribution of rations that allow supply of glucose and
the addition of glucoforming compounds (e.g., monopropylene glycol).
“Milk fever” affects cows especially at the end of the productive cycles.
It produces a clear drop in circulating calcium level, which cannot be attenuated by
calcium content by feeds (therefore decreases the absorption of calcium). It can be prevented
through a good long-term balancing of calcium and phosphorus in the rations (and other
minerals) and should be taken into consideration the relationship between anions (chloride and
sulphur) and cations (sodium and potassium).
Ruminal acidosis occurs as a consequence of the accumulation of lactic acid in the
rumen, which causes a decrease in pH. The origin of this nutritionally malady is the
consumption of rations based on cereals, rich in slightly soluble carbohydrates and in starch.
Higher amounts of cereals, generally concentrates in rations, means higher milk
production, but there is a risk of occurrence of ruminal acidosis, malfunction of the ruminal
processes.
That is why a balance must be found, which can be achieved by some prevention
measures , consist in:
- respect a transition between poor diets in slightly soluble carbohydrates and starch and
diets rich in these carbohydrates;
- providing sufficient crude fibre (at least 16-17% CF in ration DM);
- administration of hays in rations and reduction the rumen fermentation rate of cereals;
- incorporation into diets of buffers (against acidity), such as sodium bicarbonate, about
200 g/head/day.
The preparation form of feeds does not mention the quality of feeds and they have an
important role in feeding of high milk yielding cows. In this regard there are some
recommendations: the use of wilted silages (instead classically silages), the use of dehydrated
pelleted alfalfa (instead alfalfa hay), the use of extruded or expanded grains (instead un-
processed grains).
 Feeding calves

"Calf" (calves) is the term used from its birth to weaning period, when it becomes a
weaner calf.
Feeding calves during the suckling period follow their somatic evolution until weaning.
The youngest age for weaning calves belonging to the dairy breeds is 2 months; most
often, however for such calves the weaning age is 3 months. In the case of calves belonging to
the meat breeds the situation changes, because the weaning takes place after 6 months.
The feeding of calves concerns first "milk feeding" (with whole milk and/or with milk
replacers) and then "milk feeding and solid feeding “(with milk, respectively with concentrate
feeds and volume feeds).

“Milk feeding"

New-born calves must consume colostrum, as soon as possible (ideally about 2 hours
after calving, but no later than 6 hours).
Colostrum has a very high nutritionally value. For example, the first cow’s colostrum
has about 15% crude protein, 5 times more than the whole milk.
Also, comparing to whole cow's milk, colostrum has about twice as much fat (about
7%), but half of lactose (an important fact because the incidence of diarrhoea decreases).
Colostrum is also a very concentrated source of minerals and vitamins.
In addition, colostrum provides passive immunity against neonatal diseases (through
immuno-globulins and antibodies which it contains). It helps, through the laxative properties,
to removal meconium (undigested product during intrauterine period of calf).
The amount of colostrum which should be administered to calves is very important.
Mainly, in the first 12 hours after calving, the amount of colostrum consumed must
represent at least 10% of the body weight (e.g., 4 kg colostrum/day for a calf weighting 40 kg).
Furthermore, the amount of colostrum consumed by calves should be gradually
increased.
Normally, in this colostral sub-period (with 6-7 days duration) average consumption is
5-6 kg colostrum/head/day.
After the colostral sub-period it follows the feeding period of calves with whole milk
and/or milk replacers.
Calf fed only with milk, behaves, as a monogastric animal in terms of the digestion.
Rumen is not functional and less developed than the stomach. The milk goes directly into the
stomach, through the oesophageal channel. Microbial flora is only one type (lactic micro-flora).
A basic principle of feeding suckling calves is to increase the amount of milk
distributed, in order that at the age of about 3 weeks, they should be able to consume daily up
to 8 kg of whole milk or 1 kg milk replacer (powder). Then, this amount remains relatively
constant to allow consumption of solid feeds (alongside with milk or milk replacers).
About 2 weeks before weaning the amount of milk delivered is progressively reduced,
which will be completely suppressed at weaning.
If a dietary restriction is applied and the established rules are generally not followed in
the first 3 weeks after calving there will be some long-lasting consequences on the growth.

Milk feeding + solid feeding

After 3 weeks, it is necessary, for calves to be fed along with milk (milk replacers), solid
feeds (concentrate and volume feeds). This is necessary for the development of the rumen, to
diversify micro-flora, availability of milk for human consumption and weaning achievement.
Concentrate feeds are recommended to be administered ad libitum (how much the
animals can consume) starting with the age of 3 weeks.
Weaner calves must be able to consume at least 1-1.5 kg concentrates/head/day.
Concentrate feeds, usually as compound feeds, must contain also B vitamins, because calf
ruminal flora is not yet able to synthesize them.
Hays quality, particularly leguminous hays, are used traditionally in calves’ diets (ad
libitum also) and may be introduced starting with the age of 3-4 weeks. These provide a crude
fibre requirement to prevent calves’ diarrhoea.
Administration of green fodders in summer and quality silages in winter, it is also
possible after one month of age.
Among silages it is recommended primarily maize silage, with 30-35% dry matter,
which has the advantage, comparing to other silages and hays, of a more rapid growth of calves
and less expensive (with less concentrates).
Discussing generally about feeding of calves during the suckling period, one of the basic
issues remains controversial. What quantities of milk (or milk replacer) and "solid" feeds should
they consume?
Administration of large amounts of milk is the key to minimizing mortality (and
morbidity), but also obtaining higher weight gains (obviously in suckling period), but it is a
more expensive procedure.
The use of larger amounts of "solid" feeds (especially hays) allows the growth of rumen
and the obtaining higher weight gains after weaning.
Ultimately, it is an option which the farmer must assume it.
Water, completely clean and refreshed, must be ensured all the time because it helps
consumption of solid feeds and it increases ruminal fermentation.
 Feeding heifers

After weaning to the first calving, heifers (young breeding females cattle) must be fed
differently than the males (these have the primary destination fattening).
The main concern regarding heifers is related to feeding strategy.
From this point of view, it may be chosen either to achieve higher daily gains
(compatible with getting higher body weights as fast as possible until the first calving) or to
achieve lower daily gains (to minimize production costs associated with feeding).
The development of the rumen and the mammary gland must be considered and also the
conditions for the future large milk production.
Basically, it is intended that around first calving, the heifers must reach 80-85% of the
adult weight. For example, if adult weight is 600 kg, in the first calving heifers should have
approximately 500 kg.
If this weight is reached earlier is an ideal situation, because it decreases the age of first
calving. But this fact cannot be done by forcing growth, so as not to affect another objective as
rumen development and the defining of mammary glandular tissue.
Mammary glandular tissue develops from the age of 4 months and ends at puberty.
It has been found that using high feeding levels, the development of mammary
parenchyma is affected by changes in the concentration of growth hormone and estrogens in
the body.
Therefore, it is recommended a modulation of growth, responding to all objectives to be
achieved, and presented previously.
Consequently:
- from weaning (about 3 month) to 6 months, the feeding mode must allow relatively
higher weight gains, 800-900 g/day. During this time, it is speculated the high potential for
growth of animals and mammary gland development is not affected;
- from 6 months up to first insemination (towards 18 months) the diets must allow a
moderate weight gain (600-700 g/day), compatible with the proper development of the
mammary glandular tissue and the abdominal cavity;
- after fertilization, diets administered to heifers should allow a progressive and
sustained growth rate (up to 900 g/day), especially in the last two months of gestation, when
the foetus and foetal annexes really grow (now is not affected the development of mammary
tissue).
Monitoring growth with periodical weighting, will tell us how well the heifers reacted
to specific rations. Visual appraisal of heifer’s body condition can also be important in adjusting
the feeding program.
 It should be noticed that the above-mentioned data in connection with feeding strategy,
refers to heifers belonging to dairy breeds raised on farms with intensive character, where the
first birth occurs around the age of 26-27 months.
For heifers belonging to meat breeds and under pastoral (extensive) conditions, the
situation changes, because calving occurs beyond 30 months.
Starting from the objectives mentioned before, practically the feeding of heifers
translates into the use of higher quantities of volume feeds (hays and silages in winter, green
fodders in summer) and implicitly of relatively smaller amounts of concentrates.
Feeds and quantities recommended for heifers, in relation with their seasonal
availability, there will be presented further.
In the wintertime
Hays are recommended (related to dry matter and body weight) in approximative
quantities of 0.5-1 kg DM/100 kg BW/day, most often a single type.
Silages and/or roots are used in rations about 0.5-1 kg DM/100 kg BW/day.
In the summertime
From the green fodders the pasture is recommended primarily, but it can be
administered and mowed to shelters (even a combination of the two situations), in average
quantities of 1-2 kg DM/100 kg BW/day.
Throughout the entire year, regardless the season, the concentrate feeds must be
included in rations also, the average quantity being about 1.5-2.5 kg DM/head/day.
The recommended amounts of volume feeds are related to 100 kg body weight (BW)
and those of concentrates, per head.
Mineral salts, covering the calcium, phosphorus, sodium, chloride requirements are also
needed. Other minerals and vitamins are included in vitamin and mineral premixes.

Feeding fattening cattle

The largest amount of market cattle meat comes from the young specimens (especially
un-castrated males). In smaller amounts, cattle meat also comes from castrated males, from
young females excluded from breeding and cows after completing their productive cycles.
There are two main objectives of fattening animals, including fattening cattle: to achieve
average daily gains as high as possible also to obtain quality carcasses, with as much share of
meat and low share of fat as possible (which means profitability).
A very high rhythms of growth can be achieved by using specialized breeds, optimal
housing conditions, and by forcing growth using suitable rations, with a high proportion of
concentrate feeds.
 Obtaining good quality carcasses can be done in the following ways:
- choosing optimal weights for slaughterhouses (the share of the protein in the body,
hence the meat, remains relatively constant, while the fat share increases at the same time with
the increasing in body weight;
- choosing the breeds subject for fattening (on the same body weight, as precocity of
breeds is higher, fat deposition in the carcasses is more obvious; example Holstein breed vs.
rustic breeds);
- using un-castrated males for fattening (on the same body weight and the same daily
gain, females deposit more fat than un-castrated males; from this point of view, castrated males
have an intermediate position between un-castrated male and females);
- choosing optimal feeding level.
Given that, the average daily gain and its composition depend on the amount of feeds
intake, they can choose between:
* high and continuous feeding level
* low and discontinuous feeding level
Cattle fattening with high and continuous feeding level is practiced in intensive system,
where large growth rates are achieved, due to the very special conditions, including those of
nutritional nature (large quantities of concentrates in rations).
Cattle fattening with low and discontinuous feeding level is practiced in semi-intensive
system and extensive system, where are obtained lower daily weight gains, consequence of
growing conditions (not desired). From this point of view, diets are dominated by volume feeds.

Feeding fattening cattle in intensive system

The most important aspect for farmers is the efficiency of fattening. This is a
combination of several factors: feed’s cost, daily average gain, growth conditions, price, etc.
One way to measure feeding efficiency is to calculate the conversion index or factor
conversion ratio (FCR), by reporting the dry matter consumed through the feeds to one kg of
weight gain achieved.
The high weight gains can only be achieved by using high proportion of concentrates in
rations (which are more expensive), so it's necessary an optimization.
In intensive system for fattening cattle there are described several technologies and we
will present only two:
* fattening for "white meat" of calves
* classical fattening of young cattle
 Fattening for "white meat" of calves
Many European consumers, especially in the north and west, appreciate calf meat (veal),
because this meat is traditionally considered of the highest quality, associated with a "healthy"
food, a low-fat content and a very good taste.
At this type of fattening are subjected usually males, after 6-7 days after calving, at the
end of the colostrum sub-period.
Slaughtering of animals occurs between 2 and 5 months, when body weights are
between 100 and 220 kg, resulting an average daily gain between 500 and 1500 grams (at the
beginning and at the end of fattening).
Feeding can be done exclusively with whole milk or with milk replacers, or with a
combination of whole milk or milk replacers with concentrate feeds, after a certain age.
This way of feeding ensures a continuous and rapid increase in weight, a carcass well
conformed and the meat has a lighter colour, thanks to the lower myoglobin content of muscles,
as a result of iron deficiency in milk.
Whole milk is a hight quality food, but its main destination is human consumption. In
addition, after 130-150 kg of animals, whole milk does not allow the best productive
performances being administered to calves (daily weight gains in fact).
Therefore, there is recommended to use milk replacers.
The milk replacers can be divided mainly from the point of view of protein sources and
fat used in the milk replacer’s structure.
Protein sources generally derive from milk (whole milk, skimmed milk, whey, whey
protein concentrate, casein, sodium caseinate or calcium caseinate), or from alternative sources.
As an alternative source of protein there can be mentioned: soy protein isolate, soy
protein concentrate, soybean meal, animal plasma, wheat gluten meal, etc.).
Fat sources, the most commonly used are beef tallow, pig lard, soybean oil and other
oils.
Protein levels in calves milk replacers (powder form) oscillate between 20% and 30%
and fat levels from 15% to 25%.
Higher protein levels result from higher weight gains and percentage of meat in the
carcasses, but proteins are the most expensive ingredients.
Higher fat levels also lead to higher weight gains, but with this higher percentage of fat
in the carcasses, the calves are predisposed to diarrhoea.
There are three types of milk replacers for calves:
- "grower type", used in the first 6-8 weeks, with higher protein and fat content;
- "finisher type", used after 6-8 weeks of age with lower protein and fat content;
- "unique type", used throughout entire fattening period, with intermediate protein and
fat content.
 Most often, the calves receive milk replacers from automatic nurseries, provided with
teats. Powder milk replacer is placed into the machine, diluted with water (up to 12.5-13% DM,
as breast milk) and administered at body temperature.
Calves suck ad libitum, even 8-10 times per day. The amount of milk replacers
consumed, in liquid form, reaching 8-10 kg/head/day at the end of fattening.
To avoid appearance of some healthy problems, due to high milk replacer consumption,
there are recommended following advices:
- do not follow a rapid increase in body weight in the first 2 weeks of fattening, because
it requires a large amount of milk replacers, which can induce diarrhoea or other digestive
disorders; in the event of diarrhoea appearance, it is recommended the replacing of the milk,
for 24-48 hours, with an equivalent volume of rehydrating solution;
- follow a progressive increase in average daily gain; to reach this gain, it will be
increased the milk replacer concentration from 12.5-13% DM (like whole milk) to 18-20% DM;
in other words, one kg of powder milk replacer is diluted in 8 litres hot water at about 50 o C (in
the first case), or in 5 litres of water respectively (in the second case).

Classical fattening of young cattle

In this fattening system, widely practiced, there are usually used young un-castrated
males, but also castrated males, even young females rejected from reproduction.
Age and weight of slaughtering animals are dependent on market request. If the market
demand is <weak> carcasses, with a smaller share of fat, the animals’ slaughter happens around
12 months and 350-400 kg. If not, then slaughter can happen15-18 months and 550-600 kg (it
is possible for some meat breeds that slaughtering happens at higher weights).
The specialized milk breeds (Holstein, Jersey) and breeds for meat (Charolaise, Belgian
Blue, Angus) can be fattened. All these breeds are also used for crossbreeding throughout the
world.
In order to obtain meat as much as possible from an animal, the daily average gain
should be maximized, which means using rations with a very high nutritional concentration.
Two ways of feeding animals can be practiced achieving this goal:
- administration ad libitum both volume feeds and concentrate feeds;
- administration restricted volume feeds and ad libitum concentrate feeds.
The most commonly volume feeds used are silages (specifically maize silage), even in
summertime, to ensure constancy in feeding.
Concentrate feeds, usually in the form of compound feeds, include, among others,
maize, barley, oilseeds by-products, vitamin-mineral supplements.
In the case of administration ad libitum both volume feeds and concentrate feeds have
the tendency as from the total DM of rations, the young cattle to consume about 1/2 volume
feeds (v) and about 1/2 concentrate feeds (c), so that v/c ratio is 50/50. In this situation the
average daily gain (ADG) reaches, at the end of fattening, 1.4-1.5 kg.
 If the volume feeds are restricted and concentrate feeds are administrated ad libitum,
then the rations’ structure, v/c (%) can get to 20/80, which allows higher average daily gain,
even 2 kg, in the case of specialized breeds for meat production.
The problem is that, when using very large proportion of concentrate feeds in the rations,
the animals can develop some digestive disorders, such as ruminal acidosis.
Large amounts of concentrates, dominated by cereals, by their high content in soluble
carbohydrates rapidly fermented, determine a major reduction of fibrolytic bacteria (which acts
on the volume feeds, rich in crude fibre) and a rapid increase of amylolytic bacteria (which acts
on the concentrate feeds, rich in soluble carbohydrates). This leads to the decrease of the
ruminal pH, and to the occurrence of ruminal acidosis.
Acidosis can be acute (even death of animals can occur) or sub-acute (resulting reducing
of feeds intake and productive performances).
To minimize these problems, it is recommended a transition period, from smaller to
larger quantities of concentrates.
The by-products of the agro industry are an alternative to cereals for boosting the energy
content of the diets. These materials (coming from sugar factories, starch factories, distilleries,
fruit and vegetable processing plants), apart from improving digestive processes through the
higher crude fibre content, are cheaper sources and improve.
In relation to the beef quality, there has been often identified as having a relatively high
content of fat and saturated fatty acids (by reference to whole carcass).
In fact, lean beef (muscles) has only 2-3% fat. That's why, nowadays the researchers are
trying solutions for increasing the fat content of beef lean meat (associated with better sensory
qualities), a favourable spectrum of fatty acids in meat, high content in vitamins A, D, E and K,
involved in maintaining human health.

Feeding fattening cattle in semi-intensive and extensive systems

Stimulation of cattle fattening in semi-intensive and extensive systems is a must since

many years in the European Union.
This strategy aims to protect the environment, but also to obtain products of animal
origin „healthier”. As it is well known, feeding cattle with large quantities of concentrates, as
in intensive systems, induces the deposits of high amounts of fat in the body, especially at heavy
weights and the carcasses do not have the best quality.
For cattle fattened in semi-intensive and extensive systems are used low and
discontinuous feeding levels. In such situation, not only weight gains are smaller, but they are
oscillating throughout the fattening period. In other words, there is a modulation of growth rate
of animals.
 For example, during the winter, limiting the feeding level (as a necessity or as a strategy)
allows lower average daily gains (700-800 g), and during the summer, green fodders (including
pasture), if are in optimal amounts, allow to achieve higher average daily gains (1-1.1 kg).
After limiting the feeding level, such as in the winter, if follows a feeding at higher
level, such as in the summer. The animals can partially recover the delay growth in the first
period of fattening. This phenomenon is known in literature under the name of "compensatory
growth".
Animals that have been subjected to a period of under-nutrition, and thus to restricted
growth exhibit compensatory growth during a subsequent period of re-alimentation.
Compensatory growth can be a strategy for farmers. The major reasons are increasing
feeds intake upon re-alimentation, increase the absorptive capacity of the gastrointestinal tract,
the hepatic production of insulin-like growth factor-I, and a better feed conversion ratio (FCR).
Regarding the quality, it is shown that a restriction of feeds, followed by return to the
normal feeding level, may have favourable effects both on the body composition and the
features characteristic of the meat (reduction of the diameter of muscle fibre, improving sensory
qualities).
In semi-intensive and extensive systems of fattening cattle, there are subjected usually
meat breeds, males castrated and heifers rejected from breeding.
The purpose of feeding in semi-intensive and extensive systems aims the maximum use
of volume feeds and it limits the concentrate feeds in rations, no more than 30% (by reference
to DM).
The differences between the semi-intensive system and extensive system consist
essentially in duration of fattening, slaughter weight and share of the concentrates in rations.
In the semi-intensive system, the animal slaughter occurs between 20 and 30 months
(with one or two grazing seasons), a weight of 550-600 kg, and the share of the concentrates in
rations can reach 30%, sometimes even more during the finishing period.
In the extensive system, slaughter occurs more than 30 months and more than 600 kg
(can be reached higher weights, in the case of certain breeds of large format, like Charolaise or
Belgian Blue) and use smaller quantities of concentrates, sometimes no concentrates in certain
periods of fattening.
 Feeding sheep

Feed’s utilization particularities by sheep

There are many similarities, but also some differences, in the ways of using feed’s
components among ruminant species, including cattle and sheep.
Concerning similarities, fermentative processes that occur in the rumen (not only) on all
organic substances found in feeds (carbohydrates, proteins, lipids, etc.) follow the same paths.
After carbohydrates fermentation, volatile fatty acids (VFA) result in all ruminants, like
acetic acid, propionic acid, butyric acid, but also some gases result, such as carbon dioxide
(CO2) and methane (CH4).
With reference only to sheep and cattle, although the number and types of rumen
bacteria and protozoa tend to be different, VFA concentration and their spectrum appear to be
similar between the two species.
Protein’s fermentation, inclusively in sheep, consists shortly of transforming them into
peptides and subsequently into amino acids (AAs) and ammonia (NH3).
Lipid’s fermentation occurs in two major processes: lipolysis, with the production of
fatty acids (FAs) and bio-hydrogenation, consisting in transformation of unsaturated fatty acids
(UFAs) into saturated fatty acids (SFAs).
Concerning differences, related to feed’s utilization particularities between sheep and
cattle, these occur when discussing about the type of feeds consumed (their quality) and the
feeding level.
Thus, lower quality volume feeds (some hays, straws) are digested more inefficiently
by sheep, comparing to cattle.
The explanation is that the feed’s particles from such feeds, those that reach the reticulo-
rumen, have smaller dimensions (the sheep chew them better than cattle) and stagnate less time
on the digestive tract, making faster the passage rate to the intestine.
Exemplifying, digestibility of dry matter and crude fibre for lower quality feeds is
smaller at sheep with 3-4%, comparing to cattle.
The differences become more pronounced at higher feeding levels.
In this case, the adult sheep digest dry matter of poor-quality volume feeds, 5-6% more
ineffective than adult cattle.
In the opposite direction, comparing to cattle, sheep digest a little better quality volume
feed (roots, tubers, silages, etc.).
Sheep, compared to cattle, can digest better whole grains, thanks to a more effective
mastication and relatively longer length of the intestine.
If these feeds (grains) are processed by crushing, milling or other technological ways,
then they are better digested by cattle than sheep.
 Also, sheep digest better the protein from most feeds, even with 6-7%, compared to
cattle.
Sheep are by excellence, grazing animals, without it, their rising is almost unthinkable.
This fact causes a permanent fluctuation of pasture contribution in nutrients, as against
the sheep’s requirements, whether as excess or as insufficiency.
Thus, the excess of protein is excreted by animals through the urine, while the deficit of
protein leads to reduced productive performances, because sheep can hold in the body only
small amounts of protein reserves.
The same situation cannot occur when discussing about energy, because energy can be
stored in the body as fat (in the case of excess), and it can be mobilized (in the case of
insufficiency).
Starting from this last aspect, a proper feeding of sheep is related to the evolution of
body reserves along with a productive cycle.
During the repose period (after milking termination) and in the first three months of
gestation, sheep store body reserves, thanks to a high intake capacity and a relatively low
requirement.
In the last two months of gestation, intake capacity decreases as a result of lower volume
of abdominal cavity. This signifies that in normal feeding conditions, the body reserves
previous accumulated remain relatively stable.
In early lactation (about 6 weeks) sheep uses some of the body reserves to support the
high requirements for milk production, which cannot be covered only by the nutrients’ intake.
After this first part of lactation, it is recorded gradually a trend of improving feeds intake, in
connection with the development of the digestive tract.
In order to establish the corporal status of sheep (but also of other ruminant animals), it
was proposed a method, by numbering from 1 to 5.
The method involves giving the grades by performing two palpations:
- one in the lumbar region, where the importance of the long muscles is appreciated;
- another at the sternum region, the place where subcutaneous fat is stored.
The corporal status of the animal will be the average number resulting from the two-
given data.
In simplest terms, grade 1 looks like animal is extremely lean and grade 5 animal is very
fat.

Feeding rams

Although rams, in areas with temperate climate, most of the time (8-9 months per year)
are out of the mating (out of the breeding season), they must be nourished so that to be kept
permanently in breeding condition.
 Feeding strategy of the rams goes in connection to a suitable physical status, with grades
about 2.5-3 (on a scale from 1 to 5) during outside period of the breeding season and 3-3.5
during mating season.
The higher scores should be avoided, because these will have a negative effect on sexual
behaviour of rams and on semen fertility.
Sub-optimal scores should also be avoided because adverse consequences may appear,
concerning health and reproductive function.
It is also worth mentioning that, during this period (mating season) rams spend very
little time eating, because they are agitated, they move a lot. Rams can lose up to 12 percent of
their body weight during 45 days of breeding period.
Rations of rams must be well balanced, including energy and protein, also they have to
have adequate levels of vitamins and minerals. Also, the rams need table salt bricks (as well as
other categories of adult sheep) and refreshed water, which must be permanently provided.
There will be presented below, the main feeds and amounts recommended for rams.
All amounts of feeds specified are approximated because this concern the rams with
average weight also, the medium quality forages and usually the structures of rations, so these
may be higher or lower.
Feeding rams outside breeding season
This period is placed mostly during the winter, so the rams are fed mainly with
"preserved feeds".
Their rations in this physiologically stage and in winter, are most often composed by
good quality hays (1-2 kg DM/head/day, from which about 1/3 can be replaced with straws),
beet and silages (0.5-1 kg DM/head/day) and concentrates (0.2-0.3 kg DM/head/day).
But the rams can be in an extra breeding season also in the first part of the summer.
If the pastures, green fodders generally, are good quality then they can form alone the
rams’ rations during the summer, the approximative quantities of 1.5-2.5 kg DM/head/day. If
not, then they are joined in rations by concentrates, between 0.2-0.3 kg DM/head/day.
Feeding rams about 1-1.5 months before mating
This period requires using a different way of feeding, especially by increasing energy
concentration of the rations, achieved through a higher amount of concentrate feeds, up to 0.5-
0.6 kg DM/head/day.
Since this period is situated most often in late summer, along with concentrates rations
there are included green fodders (1-1.5 kg DM/head/day) and hays (0.5-1 kg DM/head/day).
Feeding rams during mating
During mating period, (August – October) usually in the temperate continental
conditions, the amount of concentrate feeds must be increased in rations, up to 0.7-0.8 kg
DM/head/day.
 Along with concentrates, there are also used in rations hays (1-2 kg DM/head/day) and
depending on the season, green fodders (1-1.5 kg DM/head/day) or roots, especially carrots
(0.5-1 kg DM/head/day).

Feeding adult ewes

During a productive cycle, that includes physiological repose (non-pregnant and non-
lactating females), gestation and lactation, the ewe’s requirements oscillate a lot.
Thus, by comparing to physiological repose, energy and protein requirements in
lactation period can be 3-4 times higher.
In the followings, there will be presented aspects related to feeding ewes, depending on
the physiological state.

Feeding adult ewes in physiological repose, mating and gestation

Feeding adult ewes during physiological repose

As it was mentioned before, ewes during the physiological repose must deposit body
reserves, which will be used later, especially in the first part of lactation. First of all, this
depends on the body status, body condition score (BCS) of animals.
If the ewes are in a poor physical condition (grades 1 or 2), the above maintenance
requirements mentioned will ensure an extra-nutrients for increasing the weight, which varies
comparing to the gain expected.
If the body condition of the ewes is well or great (grades 4 or 5), the animals may be fed
in this period only at maintenance level (no need store body reserves).
Feeding adult ewes during mating and gestation
2-3 weeks before mating it can be done a "flushing “, through a temporary energy
supplement (extra 20-30% of maintenance), with favourable effects on ewe’s fertility.
During mating and the first three months of gestation it is advisable to avoid fluctuating
diets, because these disrupt the manifestation of the act of mating and then increase the
embryonic mortality.
In the second and third month of gestation, it should be considered the placental
formation, which reaches its final development (despite of slow growth of the foetuses). Also,
bone and nerve tissues of the foetuses have a higher growth rate. In these circumstances,
especially for prolific sheep, rations contributions in nutrients should not be under the
requirements of the animals.
The end of gestation (month 4 and 5) is a delicate period, because the sheep’s
requirements grow rapidly (foetuses done about two-thirds of their maximum weight in the last
6 weeks of gestation) and the animal ingestion capacity decreases.
 Requirements of the ewes in the last 2 months of gestation are calculated based on the
mothers’ body weight and expected weight of fetuses at birth (these values are added to the
maintenance requirement, to determine the total requirements).
In the last 6 weeks of gestation, towards early gestation, the ewes carrying a single lamb
require 50% more energy, and the ewes carrying multiple lambs require 75% more energy.
The energy requirement in the last 2 month of gestation, based on the mothers’ body
weight and the weight of foetuses, should be regarded as the minimum, because it also depends
on the ewe’s body condition score. Therefore, if the body status of ewes is under 3, it is
recommended the increasing by 10%.
Requirements of ewes in late gestation are proportionately higher than in cattle, because
sheep foetuses have a higher proportion from the total body weight. This situation partially
explains why the most of metabolic problems occur in late gestation in sheep, while in cows
appear in early lactation.
Normally, during this period (last 2 months of gestation) the sheep must maintain a
relative constant body weight (without considering foetuses). It is accepted, however, a slight
decrease in body weight.
If it is recorded an exaggerated mobilization of body reserves (mainly energy) it may
decrease the weight of lambs at birth or appear pregnancy toxemia, which induces abortions,
even sheep death.
Malnutrition in late gestation can induce also decreasing fat reserves of lambs at birth,
and hypothermia can occur under these conditions (especially since the birth usually take place
in the winter).
However, on long-term such situation can affect the development follicles of wool fibre.
These negative effects of malnutrition are more obviously in the case of super-ameliorated
breeds.

Feeding lactating ewes

Correct feeding of lactating ewes is vital for the survival and rapid growth of the lambs.
In most cases, the ewes cannot cover the full requirements in nutrients in the first weeks
of lactation and, therefore, they mobilize some body reserves (unlike the latter part of
pregnancy, this mobilization, especially fat, does not imply serious pathological risks for
mothers and lambs).
During the first month of lactation, it is accepted a loss of weight of ewes, about 2 kg,
it oscillates depending on the weight before the birth.
Feeding lactating ewes differs from the feeding of not milked ewes (in the first part of
lactation) and from milked ewes (obviously after weaning).
This delimitation does not have a physiological support, but it helps a better
understanding.
 Feeding not milked lactating ewes

Traditionally, in the first part of lactation (between birth and lamb’s weaning), rustic
breeds ewes are not milked.
Normally, there are some exceptions. One of them refers to the ewes from ultra-
specialized breeds, with high milk production. Also, the ewes can be milked during this period
if the lambs receive milk replacers.
Lactating ewes typically reach maximum milk production at 3-4 weeks after lambing.
In the traditional situation, when ewes are not milked, it is not known exactly the milk
production level or the main criterion to establish requirements.
Therefore, considering this fact, the requirements are determined according to the stage
of lactation and weight gain of lambs breast-feeding.
In connection to the stage of lactation, we have established through many experiences,
lactation curves for the main breeds, through which we can approximate the milk production.
Regarding weight gain of lambs breast-feeding, it is considered that in the first part of
lactation for achieving one kg weight gain, they need about 5 kg milk.
It should be noticed that, not enough intake of energy and protein, below that provided
by requirements, translates into reduction of milk production. The decreasing of the growth rate
of lambs should be stopped by administering more concentrate feeds after 2-3 weeks of life.

Feeding milked lactating ewes

After weaning, when it can be established with precision the level ewe’s milk
production, requirements are calculated easier, by summing up the maintenance and milk
production requirements. Also, it should be considered the fact that, chemical composition of
the milk changes, as lactation progresses.
Milk fat increases constantly from lambing to the end of milking, from 5.8% to 8%, and
the milk protein increases up to the 4th month of lactation, from 4.8% to 6%, after which it
remains about at the same level until the end of lactation.
This means that, the energy and protein requirements to produce one kg of milk at the
beginning of lactation will differ from the ones at the end of milking.
Regarding feeding mode of lactating ewes, we can make the following
recommendations:
During the winter period
In the wintertime, which generally corresponds with the first part of lactation, ewes
may receive in rations 1-2 kg DM/head/day hays and straws (alfalfa hay, clover hay, permanent
pastures hay, peas straw, maize straw, etc.), 0.5-1 kg DM/head/day succulently winter feeds
(silages, beet) and concentrates.
 Concentrate feeds are included in the rations up to 0.7-0.8 kg DM/head/day, depending
on potential level of ewe’s milk production.
Normally among the concentrate feeds, cannot miss maize, barley, wheat bran, peas,
sunflower meal, soybean meal, mineral salts and vitamin-mineral premixes.
During the summer period
In the summertime, traditionally corresponding to the last part of lactation and "dry
period“(when milking stops), the green fodders can form themselves the entire rations, in
approximate quantities of 1.5-2 kg DM/head/day (usually by grazing, but also mowed to
shelters).
To support milk production and to extend lactation period, it is recommended to add in
rations concentrates, between 0.2-0.3 kg DM/head/day.

Feeding young sheep

Feeding young sheep, as in the case of other young categories, is divided in two periods:
before weaning and post-weaning.

Feeding young sheep before weaning

Feeding mode of lambs in the first few weeks has a decisive contribution to their future
productive performances.
Until weaning, lambs are fed in the following sequences: only with colostrum, only with
breast milk (or milk replacer) or with milk plus dry feeds (concentrates, hays).
Like other new-borns, lambs must necessarily consume colostrum as soon as possible,
at least 50-100 g/day, or from mothers, from sheep which gave birth in the same period.
The colostrum provides through its immuno-globulins, especially in the first 24-36
hours from birth, passive immunity to lambs. Colostrum immuno-globulins reach completely
in the intestine, but their absorption gradually decreases after two days of age.
After colostrum sub-period, in the most situations lambs are fed ad libitum with milk
provided by their mothers.
The average amount of milk that can be consumed by a lamb (about 2-3 weeks after
birth) is 1-1.2 kg/day.
There are two ways of breast-feeding of lambs, namely: one uncontrolled (lambs stay
with their mothers all the time) and another controlled (lambs have access to the suck only for
a period of time).
If ewes are raised in intensive system, as is the case of ultra-specialized breeds for milk
production, after 24-48 hours from birth, the lambs can be fed with milk replacers, in these
situation ewes being able to be milked.
 Lamb's milk replacers (powder) are other than those used in calves and have a higher
nutritionally concentration, reaching even 30-35% fat and 20-25% protein.
In fact, the use of milk replacers produced for calves did not work well in lambs, due to
lower fat and protein content and higher content in lactose.
After 2-3 weeks since birth (when is recorded maximum milk yield of ewes), milk
production starts to decline and requirements of lambs increase, starting with this period, it is
necessary to use also solid feeds, represented by compound feeds and good quality hays.
Even compound feeds administered ad libitum, at the beginning are consumed in very
small quantities. Afterwards, however, their consumption increases gradually, especially if they
have a proper composition, some form of presentation (granules) and if all lambs have
permanent access to them.
The administration of hays, as in the case of other young ruminants, allows good
development of rumen and prevents diarrhoea.
Moreover, consumption of solid (dry) feeds is a necessary condition for early weaning
of lambs, starting with the age of 5 weeks (traditionally weaning takes place at about 8 weeks).
At a lower weaning age, it is created an opportunity that afterwards the lambs will
consume a smaller amount of feeds, and thus decrease the weight gain.
It is appreciated that around the weaning period, lambs should be able to consume 250-
300 g solid feeds per head/day (concentrates and hays).

Feeding young sheep post-weaning

Farmers should prepare the ewes several days prior to the planned weaning date. It starts
with removing concentrates from the diets of the ewes and switch to lower quality hay. This
abrupt drop in protein and energy levels will cause the ewes to decrease milk production.
After weaning, young sheep are fed depending on the direction they will follow, females
for breeding and males for fattening.

Feeding young sheep breeding females

Young sheep breeding females are given usually to mating in the autumn of the same
year from birth, with the condition they have a minimum age of 7-9 months and sufficient body
development (2/3 of the adult weight). If they do not meet these conditions, they are given to
mating next year.
As in the case of heifers, an important aspect for young sheep breeding females is related
to the feeding level.
A low feeding level after weaning will subsequently affect fertility and prolificacy.
Also, too high feeding level, which will allow a rapid increase in weight after the age of
three months, during differentiation of the mammary glandular tissue, leads to a subsequent
reduction of milk production.
 It is therefore necessary a modulating of females feeding mode during their growth
period, as follows:
- up to 3 months of age it is recommended to use a high feeding level, with relatively
large amounts of concentrates in rations, which it will allow to achieve 22-28 kg body weight
(200-250 g gain/day), depending on breeds
- between 3 months and mating entry it is recommended a lower feeding level to
determine a moderate growth rate (100-150 g gain/day), even without concentrates in summer
rations.

Feeding young sheep fattening males

Males raised for meat production are generally fed at high feeding levels, to allow
expression of the full genetic potential for growth. However, there are situations in which there
can be adopted lower levels of feeding, due to the existence of small amounts of concentrates
and for the limitation of fat deposits in the carcasses.
In the intensive systems for meat production, it is intended to achieve higher body
weights, within the shortest possible time.
Under these conditions, around the age of 5-6 months males have about 40-45 kg, with
a growth rate throughout entire period of 200-250 g/day (on the last phase of fattening they can
register about 300-350 g /day). It is true that, at such weights the quality of the carcasses
decreases.
However, in the traditionally system, young males are slaughtered at lower weights,
even 7-8 kg, in order to obtain a very thin carcasses and the meat has to have a certain flavour.
This is the case met in the Mediterranean countries of the EU or in the Balkan countries.
The problem which occurs in this situation is the proportion of meat in the carcasses,
which is smaller and generally is not an economically solution.
That is why, in the last years in the mentioned regions it is manifest the tendency of
increasing the weight of the males on slaughter at about 14-15 kg (as one variant) or 25-30 kg
(as a second variant), without significantly affecting the carcasses quality or the features of the
meat.
In order to obtain higher weight gains in intensive systems it is necessary to use large
quantities of concentrate feeds in rations. But, using excessive amounts of concentrates for
fattening young sheep it can lead to the appearance of some healthy problems, due to
malfunctional of the internal organs (rumen, kidney).
It is known in this regard, a disease called "urolithiasis" which affects the kidney,
through the formation of kidney stones, due to excess of phosphorus originated from
concentrates.
 The disease occurs usually at the end of fattening and affects the best and the healthiest
animals, through the fact that such animals dominate the others and they consume large
quantities of concentrates (these are offered in common feeders).
Preventive measures of nutritionally order which can be taken are the follows:
- limiting quantities of concentrates in the rations, up to 700-800 g/day at the end of
fattening, and these should be crushed (milled less);
- inclusion in the rations of leguminous hays (for their high calcium content and to
stimulate rumen activity);
- limiting in concentrates mixtures of wheat bran, with higher content in phosphorus;
- increasing the amount of table salt (NaCl) in the structure of rations and free access to
drinking water;
- using ammonium chloride, 1% in the dry matter of rations, for solubilisation kidney
stones.
In relation to the type of rations used in young sheep fattening males, we can choose the
same type of ration throughout the entire fattening period or two types of rations, one for the
growing phase and one for the finishing phase.
When adopting the solution to use two types of rations, these are differentiated by the
level of nutritionally parameters.
Most often, the energy level is about 2.5 Mcal ME/kg DM and 18% CP in ration’s DM
in growth phase and 2.8 Mcal ME/kg DM and 14% CP in ration’s DM in the finishing phase.
 Feeding horses

Feed’s utilization particularities by horses

Horses, non-ruminant herbivores, have several digestive features, distinct to

those of other species of animals, which influences the degree of feed’s utilization in
the body.
Several studies compared in particular digestion between horses and cattle.
The differences in digestibility between horses and cattle depend on the type
of feeds.
From this point of view, horses digest perennial leguminous hays (alfalfa hay,
clover hay) similar to cattle if these have relatively lower crude fibre content (among
hays).
However, as the crude fibre content of forages increases, the rate of digestion
decreases on horses, compared to cattle.
In simple terms, digestion in the stomach and small intestine on horses is quite
similar to that found on pigs, and the digestion in the large intestine (especially in the
cecum) is almost identical to that found in ruminants.
Digestion in stomach is decisively influenced by its capacity, which
represents in adult horses only about 10% of the whole volume of the digestive tract.
This makes that the transit rate through the stomach to be fast, especially if the
quantities of feeds consumed at a meal (portion) are higher. Therefore, it is
recommended that horses to receive meals several times per day, and in smaller
portions.
When the stomach remains empty for a long time, excess gases produced can
cause its rupture, which can even end with the animals’ death.
Gastric digestion in horses is limited and concerns in particular proteins (it is
actually the beginning of digestion, following in the intestine).
Digestion of other constituents of feeds in the stomach is very low (case of
carbohydrates) or almost zero (case of fat or minerals).
One specific horses’ issue is the phenomenon of stratification of feeds in the
stomach.
Fibrous feeds (hays, straws) are situated on the greater curvature of the
stomach and concentrates on the centre, so the watering of the horses and the
administration of fibrous feeds must be done before the administration of concentrate
feeds. Otherwise, the latter (concentrates) are incompletely digested, and moreover
appear abdominal pains (colic) and other digestive disorders.
The small intestine is the essential place of digestion and absorption.
 Like in the stomach, if horses eat too many feeds in a single meal (portion),
the transit rate through the small intestine increases.
In the small intestine there are digested the protein, the fat and the non-
structural carbohydrates (like starch, simple sugars).
The main terminal products of digestion in the small intestine are glucose and
amino acids. These are absorbed and they provide energy and protein for animals.
The amounts of energy and protein absorbed in the small intestine depends on
the share of concentrate feeds and volume feeds in the rations.
Vitamins and calcium are absorbed mainly in the small intestine. Other
minerals, mainly the phosphorus, will end up in relatively large amounts in the large
intestine.
The large intestine, the most developed segment of the digestive tract, is the
place where the constituents of feeds which are not degraded in the stomach and small
intestine (headed by crude fibre) are converted into nutrients absorbable, through a
diverse and active microbial population, located mainly in the cecum.
The cecum, respecting proportions, behaves on horses like the rumen behaves
on ruminants.
Here are produced also volatile fatty acids (VFA), which provide for fibre-
based rations (dominated by hays and straws, for example) about 2/3 from the total
energy absorbed.
If the share of the concentrates in the rations is high, in addition to the lower
amounts of VFA, these (concentrates) are rapidly fermented and there are produced
excess amounts of gases and lactic acid.
In such situation, health problems arise, such as colic (cramps).
Colic is an abdominal pain, often fluctuating, caused by intestinal gases or
intestine obstruction (in some situations, both the small intestine and especially the
large intestine are obturated, due to the different diameters of their segments and
flexuosity).
It can also appear laminitis (inflammation of the soft tissues inside the
hooves).
In the large intestine there are produced also some amounts of microbial
protein and B vitamins, but their degree of absorption at this level on digestive tract is
very low on horses (in comparison with ruminants).

Feeding stallions
 Many consider the stallion to be the star of the farms, and very large amounts
of money are spent in the world for promoting stallions to attract suitable mare’s
owners.
The reproductive performances of stallions are influenced by their healthy
status, by stress factors and by feeding mode.
Feeding certainly plays a key role in keeping the stallions in good reproductive
condition, both before and during the mating season.
The way of stallions feeding depends on their body condition score (BCS).
Ideally, stallions should be in a moderate body status (grades 5 or 6 on a scale from 1
to 10) throughout the entire year.
Some stallions can decrease in weight during the breeding season, while others
are able to maintain a relatively constant body weight.
Therefore, the body condition score during the mating season must be
permanently monitored and eventually it may be adjusted by the feeding mode.
If stallions have grades of body condition score below 4, they do not have
enough energy to support breeding activity throughout the mating season. Grades too
high, 8 or 9, lead to the reduction of libido and the appearance of healthy problems
(arthritis, laminitis, heart disease).
Regarding the concrete ways of stallions feeding, there will be made some
clarifications, both for those which are in rest (repose) period and for the ones in the
mating season.
Stallions feeding outside the breeding season
From August to February (in temperate climate), when stallions are considered
in sexually repose, their requirements correspond to the ones for maintenance, but
with 10-15% higher towards other categories of adult horses, like mares and working
horses.
It is possible that during the sexually repose, if stallions have a properly body
status and they are not used in other activities (riding, work), they will be fed only
with volume feeds (without concentrates). Volume feeds, like green fodders during
the summer and hays + roots during the winter, are administered in limited quantities
that may satisfy the nutrient requirements.
If the body condition score (BCS) is deficient and the quality of volume feeds
is lower, there should be used in rations also concentrate feeds, mainly cereals, in
indicative amounts of 1.5-2 kg DM/head/day.
Stallions feeding in mating season
Between March and July, approximate corresponding to mating season in
temperate climate, the requirement for maintenance is supplemented by the
requirement related to the reproduction activity, quite variable in size, depending on
the breeding intensity. Reproduction supplement, from the maintenance one, is
between 15 and 25%.
It is not advisable to get over these additional values to avoid fattening of
stallions.
During reproduction season (mating season), the emphasis should be put on
the quality of volume feeds, especially hays.
And now, in this mating period, the volume feeds represent the main
components of the rations, both in the winter and in the summer (as stated in other
situations, regardless of the season, but according to the available feeds, preserved or
fresh).
In wintertime it is recommended hays (about 5-6 kg DM/head/day, especially
perennial grasses hays) and carrots (2-3 kg DM/head/day).
But it is possible that a part of the quantities of hays and carrots to be replaced
with good quality silages (there are not recommended perennial leguminous silages,
mainly alfalfa silage, because they produce undesirable fermentations in the large
intestine).
During summertime, there can be used in rations as volume feeds, hays about
2.5-3 kg DM/head/day (half of the amount recommended in the winter) and green
fodders (3-4 kg DM/head/day).
But, during mating season it is mandatory to include concentrates in the
rations, in amounts depending on the intensity of breeding.
For example, when using intense breeding, the recommended amount of
concentrates is 3-4 kg DM/head/day, or about 40% of the rations structure (related to
DM), following to decrease when the mating intensity decreases.
Regardless of the season and breeding intensity, some essential amino acids,
especially methionine, involved in the quality of the sperm, will be considered in the
rations.
Vitamins and minerals should also be provided at optimal levels, with an extra
consideration for some vitamins (A and E) and some minerals (calcium, phosphorus,
cobalt, zinc, manganese, and selenium).
If the stallions receive well balanced rations to cover strictly their
requirements there is not the case to add supplements of vitamins and minerals,
because fertility is not improved.

Feeding mares

Proper diets, a correctly feeding mode, influences both the mares themselves
(health, milk production level, milk composition) and foals’ development.
 During gestation and lactation, the main nutritionally parameters taken into
account are energy and protein.
It should be also taken care of some minerals (calcium, phosphorus,
magnesium, iodine, cobalt, zinc, manganese) and vitamins (A, D, E), all involved in
optimizing breeding performances of mares and normal foals’ development.
During the first 7 months of pregnancy the development of fetuses is low, so
the mares’ requirements during gestation are also low.
In the last 4 months of gestation, the growth rate of fetuses intensifies, so
obviously the requirements of mares increase.
Notice that at birth, the mares lose on average 10-15% of their body weight
(by fetuses, fetal liquid, fetal annexes) and in the first 2-3 weeks after parturition they
mobilize part of the body reserves.
It is intended that, these weight loss in the first 2-3 weeks, after farrowing not
to be higher than 5%, because it can compromise breeding performances by delaying
re-fertilization.
This may happen because farrowing occurs most often in early spring, when
feeds are insufficiently and poor qualitatively.
Requirements of mares are determined based on the amounts of nutrients used
for maintenance, for production (foetal development, milk synthesis) and on the
specific efficiency of using nutrients for different physiological functions.
On the physiological stages, the higher requirements are recorded in lactation,
especially in its first part, when milk production is maximized.
For example, in the first month of lactation (milk production appears to reach
a peak at 30 days after farrowing), the total energy and protein requirements are
higher 2.5-3 times, than for maintenance requirements. In fact, the nutrient
requirements of lactating mares are higher than those of any other class of horses,
with the possible exception of the racehorses in full training.
In connection to the practical feeding of mares, there are several ways
dependent on the type of foals (intended for sport or for work), the possibility of using
mares to work and housing conditions (closed shelters or open shelters).
Generally, mares which give products intended for sport are fed with greater
accuracy than those who give products intended for work. This rigor consists in
selection of good quality volume feeds and using larger amounts of concentrates in
the rations.
Mares producing foals for work can be fed with small amounts of
concentrates; also, volume feeds (including hays) can be of medium quality and in
addition, part of hays (about 1/3) can be replaced by straws.
 The mares used for work and reared in open shelters, especially in winter, will
receive additional quantities of feeds, comparing to the ones unused for work and
reared in closed shelters.
During gestation, which coincides generally with the winter season, hays
(especially grasses hays) are administered in average amounts of 5-6 kg
DM/head/day. These can be accompanied in rations, as volume feeds, by fodder beet
and silages (2-3 kg DM/head/day). The concentrates are included in the rations in the
maximum amount of 2-3 kg DM/head/day.
In the first part of lactation, if it is in the winter, the amounts of hays grow at
least to 7-8 kg DM/head/day and the concentrates grow also, to 4-5 kg DM/head/day.
If early lactation is placed in the summertime there are used, instead or
alongside with hays, green fodders, up to 5-6 kg DM/head/day, but also concentrates,
4-5 kg DM/head/day.
In the second part of lactation, most commonly in the summer, the share of
volume feeds in the rations structure increases (green fodders in fact), and implicitly
the share of concentrate feeds in rations decreases.
It should also be noticed that mares, horses in generally, consume much more
if they need if they have the opportunity.
This aspect should be followed, especially during pregnancy, to prevent
excessive fattening of animals, with negative effects on farrowing.

Feeding young horses

Feeding plays a very important role in obtaining foals able to reach their
genetic growth potential. A prolonged and incorrect feeding mode can affect
development, accompanied by changes in animals’ conformation.
Under normal feeding conditions, the farrowing foals have 8-12% of the
mother’s weight, namely 45-55 kg for those which belong to light breeds and 65-75
kg for those which belong to heavy breeds.
During the first month of life, foals nearly double their body weight, which
means an achieved average daily gain (ADG) of about 1.5 kg.
At weaning (6-7 months) if foals belong to light breeds, they reach to 200-250
kg and 300-350 kg if they belong to heavy breeds.
At the age of two years, foals have about 70% from their adult weight,
following that the completion of growth must take place between 4 and 5 years.
This intense process of growth is influenced no doubt by breed, gender,
growing conditions, including feeding mode.
 Feeding strategy, especially in the first year, refers to the use in rations of
quality feeds and with optimal volume feeds/concentrate feeds ratios (proportions).
Yearlings should generally consume 50% volume feeds (hay and pasture,
depending on the season) and about 50% concentrate feeds, in the rations dry matter
structure.
After that, especially towards the end of the growth process and for the young
horses intended for work, the share of volume feeds increases, compared to
concentrate feeds, up to a ratio 70/30, along with increasing intake capacity.
As in the case of other young animal species, feeding mode of the young
horses must be differentiate before and after weaning.

Feeding young horses before weaning

The requirements of foals in the first 3 months are largely covered by breast
milk.
However, from the age of one month there are recommended to be
administered also dried feeds, represented in particular by concentrate mixtures
(compound feeds) and the best quality hay. This happens because the milk production
of the mares decreases, and the growth rhythm of the foals increases.
To allow only foals to have access to their dry feeds, the mares have to be tied
up during eating, or they have to be enclosed separately.
It is not recommend using concentrate feeds ad libitum, in order to avoid high
growth rates and certain skeletal abnormalities. The amount of concentrates will
increase gradually, so that towards the age of three months to get to 1.3-1.5 kg
DM/head/day and around weaning to 1.5-2 kg DM/head/day.
More than other categories of young specimens belonging to other species, a
particular attention for young horse’s rations will be given to their contributions in
minerals, especially calcium and phosphorus, in order to avoid a possible osteopathy.

Feeding young horses after weaning

After weaning, feeding strategy of young horses is correlated with their

destination (for sports or for work).
Young horses for sports receive rations very well balanced in all nutrients,
induced by adequate compound feeds (or concentrate mixtures) and highest quality
hays.
Young horses for work can be fed with rations that have lower nutrient
concentrations, especially in the winter. In these circumstances, grass grazed in the
summer will be better used in the body, through a compensatory growth.
 If the weight gains made in the summer are too low, compared to a normal
situation, then in the following winter specific rations should be administered to
compensate the growth delay.
For both categories of young horses (for sports or for work), concentrate feeds
will be used restricted (2-2.5 kg DM/head/day) and hays will be administered ad
libitum.
These limits of concentrates recommended should not be exceeded, because
there may appear some disorders, like developmental orthopedics diseases (DOD).
DOD is manifested by osteocondrosis (articular cartilage disorders),
contracting tendons, legs deformities, etc. Nutritionally causes of DOD occurrence are
excess of energy and protein and inconvenient minerals balance.
In order to prevent the occurrence of DOD it is therefore advisable to limit the
share of the concentrates in the rations (which results in moderate weight gains) and
the proper balance of rations in all nutrients.

Feeding working and sports horses

Movement (effort) involves firstly an increase in energy requirement, due to

skeletal muscle activity and enhancing circulatory and respiratory functions.
This increasing of energy requirement is depending on the nature, intensity
and duration of the exercise.
The available energy for effort comes mainly from carbohydrates (glucose,
reserve glycogen), but also from fat.
With the intensification of metabolism, as a result of the effort, the protein
requirement increases.
It can be deduced that, a higher amount of protein consumed, more than it is
necessary, does not make any contribution to the effort, and it can have unfavourable
consequences on the animals.
This happened because the excess protein is not eliminated entirely through
urine (especially) and faces, which means that a part is retained in the body. Under
these circumstances, appears fatigue, increasing heart rate, ammonia in the blood and
the amount of lactic acid in the muscles.
Minerals and vitamins requirements also increase if horses make effort, but
not in a significant manner.
There are recorded increased minerals level especially in intensive efforts, in
the case of sodium (which is lost through sweating, especially in the summer),
calcium, phosphorus, magnesium and iron.
 Vitamin E intervenes in muscle activity, because it is a component of
antioxidants group. When horses that make effort do not have access to pasture
(generally to green fodders), then B vitamins complex must be taken into account
when formulating rations, especially thiamine.

Feeding working horses

It is obviously that, the requirements of working horses depend on the

magnitude and duration of the effort.
From this point of view, it can be accepted with some approximations, that the
effort of horses can be classified as:
* slightly effort, about 1-2 hours/day effective work;
* moderate effort, about 3-4 hours/day effective work;
* hard effort, about 5-6 hours/day effective work.
Also, the effort of working horses can be differentiated depending on the type
of activity:
* slightly effort (e.g., mowing plants in the plains areas);
* moderate effort (e.g., seeding in the plains areas);
* hard effort (e.g., seeding in the hill areas).
Generally, depending on the type of effort, energy requirement increases,
compared to maintenance requirement, with about 30% for slightly effort, 60% for
moderate effort and 90% for hard effort.
Protein requirement, also related to maintenance requirement, increases with
about 15% for slightly effort, 30% for moderate effort and 45% for hard effort.
Feeds and quantities recommended for working horses are correlated to the
specificity of this productive form (effort).
Concentrate feeds, represented in particular by oat, barley and maize (energy
concentrates) are the basic feeds for working horses, because these can provide to
animals immediately available energy and restoration of body reserves in glycogen.
In the case of a moderate effort, the ratio between concentrate feeds and
volume feeds in the diets is about 40/60, namely, from the rations dry matter,
concentrates hold about 40% and volume feeds hold about 60%.
In the case of slightly effort, it decreases notable the share of concentrates
feeds (toward 20%), and in the case of hard effort this one increases (toward 50%).
Other basic feeds for working horses are hays, even in the summer, especially
during hard efforts.
During the winter, if the horses are in resting (repose) time, they may be fed
only with hays (recommended grasses and naturally hays), average quantity 8-10 kg
DM/head/day. Some of these hays, up to half, may be replaced with straws, in which
case the rations include also 1-2 kg DM/head/day energy concentrates.
Also in the winter, if horses are submitted to effort, it is possible to use as
volume feeds also beet or silages (recommended grasses silages), the average amount
2-4 kg DM/head/day, substituting part of hays.
At medium and heavy effort it will increase the amount of concentrates in the
rations, up to 4-5 kg DM/head/day.
During the summer, if the horses are in repose they can be fed only with
green forages, up to 5-6 kg DM/head/day.
If they make medium or heavy effort in rations there are required also hays,
even straws, up to 4-5 kg DM/head/day, obviously along with concentrate feeds (like
in the wintertime).

Feeding sports horses

Sports horses are superior athletes. Some of the physiologic adaptations

include high maximal aerobic capacity, large intramuscular stores of glycogen,
specific ratios of muscle fibre types, splenic contraction to increase circulating red
blood cells, and the ability to regulate heat stress through sweating.
Sports horses have variable requirements, given by the intensity and duration
of the exercise.
This mode of assessment has led to distinguish for sports horses 3 types of
effort:
* easy effort (e.g., pleasure ride);
* medium effort (e.g., dressage, jumping);
* hard effort (e.g., racing in trotting and gallop competitions, polo, and
endurance).
Rations for sport horses are made from ordinary feeds, used usually for all
categories of this species.
For the sports horses, performing more effort and during competitions,
concentrate feeds are actually compound feeds granulated, with complete nutritional
values. Also, during competitions volume feeds (actually hays) are given in the pellets
form.
For intense effort during competitions, a dietary fat source should be
considered. Substituting part of the grains with vegetable oils (soybean oil, canola oil,
etc.) can reduce the risk of colic and laminitis appearance.
For sports horses, rations are set individually and weekly, depending on their
program. Generally the number of daily portions is three: morning, noon and evening.
 Concentrates are distributed in equal shares into three portions and volume
feeds depending on the time when effort is scheduled.
The best time to distribute a concentrate feed portion before riding is at least 4
hours.
Blood glucose and insulin increase when the horses eat cereals. Horses that
begin exercise with elevated insulin may fatigue quicker, because insulin prevents
muscles from making the best use of nutrients needed to fuel muscle contraction.
Allowing at least 4 hours between a grain meal and exercise will permit that blood
glucose and insulin to come back to baseline, leaving muscles to work optimally .
There is not recommended the administration of feeds immediately after
submitting effort, because digestive functions are at a low level, and they can cause
digestive disorders.
For the sports horses performing great effort, the concentrates represent about
50% of the rations dry matter structure, or 4-5 kg DM/head/day. The concentrates
amount decreases to 1-2 kg DM/head/day during resting time.
 Feeding pigs

Feed’s utilization particularities by pigs

Pigs are monogastric omnivores, with digestion features and feed’s utilization
particularities different from other animal species.
The relatively lower digestive tract capacity in pigs and decreased degree of
using crude fibre (at least compared to ruminants) requires the use in the diets of large
amounts of concentrate feeds, sometimes exclusively.
In connection to the crude fiber, its level is limited in rations dry matter for
pigs, up to 3-4% in young animals and up to 7-8% in adult animals. Otherwise, it will
occur a significant lower degree of using in the body of all components of the feeds.
In the intensive system there are used only concentrate feeds in pigs’ feeding,
where animals are kept in enclosed spaces, with betony floors, at high densities, and
in shelters the temperature and the ventilation are constantly controlled. In this
situation, there are used complete compound feeds, often administered ad libitum, as
in the case of fattening pigs and lactating sows.
It is important to noticed that, currently hybrids of pigs reared in intensive
systems are totally different comparing to classic breeds, being selected to be capable
of a higher intake capacity, faster growth rates, and higher conversion rates of feeds in
the body and to submit more meat and less fat in the carcasses.
In the traditional system (extensive system), pigs are kept in larger shelters
with straw or other similar materials placed on the floor. The pigs have also access
outside in the open air.
In this case, along with concentrate feeds, there are used in rations also some
volume feeds (tubers, roots, green fodders), those that contain lower proportion of
crude fibre and therefore higher digestibility. The share of volume feeds in the dry
matter of rations should not exceed 30-35%.
If we talk about organic husbandry of pigs, then it is important to notice, that
this requires an integrated farm approach, which takes into account some reasons in
connection to sustainability, environmental protection and animal welfare.
In terms of feeding mode, pigs raised in organic farms differ from those raised
in conventional conditions. Sources of feeds, including cereals, are produced without
the use of chemicals (fertilizers, insecticides, fungicides) and genetically modified
plants. Synthetic amino acids, other additives produced by chemical synthetics are not
used in the rations.
 Normally, all these aspects regarding organic farming have an important
impact on the effectiveness of feed’s utilization (which is lower), on feeding cost
(which is higher).
Unlike ruminants, pigs need better balanced rations, including amino acids and
vitamins, because their diets depend on these. It is known in this regard that, the first
limiting amino acid for meat production is lysine, which must be provided at the level
required, obviously alongside with other amino acids and other nutrients.
In the large intestine, especially in the cecum and the colon, B vitamins
complex are synthesized, but their rate of absorption is very low.
Here (in the large intestine) are produced also the volatile fatty acids (VFA),
from the degradation of the residual carbohydrates stored here, similar to what is
happening in ruminants, but these (VFA) provide a smaller part of the total energy
absorbed.
Digestion particularities in pigs cause a certain way of feed’s preparation.
Concentrate feeds grounded, wetted, extruded, or expanded are generally better used
in the body.
An important role in the nourishment of this species is also linked to taste and
smell of the diets, pigs having more developed senses than other species. This is the
reason for which, in certain situations, especially for young animals, feeds are
subjected to some processes of saccharification and flavouring.
In pigs the control feed intake is determined primarily by hormonal and neural
mechanisms (especially through hunger and satiety centres, located in the
hypothalamus).
It is worth mentioning at the end of this subject, a few digestive features of
piglets.
After birth, the intestine is permeable to native milk proteins. This is essential
for the transfer of gama-globulins (antibodies) from the mother’s milk because the
ability declines rapidly after 24 hours post-partum. At birth the activity of pepsin,
alfa-amylase and sucrase is low, while lactase activity is initially high and decreases
as the piglets advance in age.
These differences in enzymes activity are important when there are concerns
about the age of weaning. If piglets are weaned earlier, at 2-3 weeks, their dried diets
(compound feeds) should be different from those of older weaned piglets, at 5-6
weeks.
 Feeding pregnant sows

In the case of females from other species, for sows it is recommended to

perform a flushing. Also it is recommended a temporary energy over-nutrition, 7-10
days before mating, because it was noticed an increase in the ovulation rate. This fact
is more important for sows with a deficient body status before the mating.
The most important aspect of feeding pregnant sows is related to the fact that,
the diets are administered restricted. This feeding mode has favourable effects on both
primiparous sows (after the first birth) and multiparous sows.
The beneficial effects of restricting feeds intake are related to the number and
weight of piglets at birth, the feeds intake of sows in the future lactations and the
embryonic mortality. Only that, if the pregnant sows are raised in groups, all must
have access to the diets at the same time.
Pregnant sows reared in intensive system are fed only with compound feeds
(CoF). Such compound feeds must have certain nutritional parameters.
Energy parameter most often is around 2900 kcal metabolisable energy (ME)
per kg CoF, and the protein parameter level is 12-13% CP (crude protein) in CoF.
Pregnant sows can get diets more diluted in terms of energy, to 2800 kcal
ME/kg CoF. Such CoF are those in which, along with conventional feeds, there are
introduced also some feeds with a higher level of crude fibre (e.g., alfalfa flour,
dehydrated beet pulp). The advantages of such compound feeds are those that
stimulate intestinal peristalsis (avoid risks of constipation towards the end of
pregnancy) and ensure greater satiety feeling. The disadvantage is related to
increasing compound feeds consumption.
There can be used also compound feeds with an energy level toward 3000 kcal
ME/kg CoF. With such compound feeds the consumption can be decreased, but
animals accuse hunger. In this situation pregnant sows are agitated, and the moment
they are in groups it can occur abortion.
In order to achieve the nutritional parameters mentioned (and others), the
indicative general structure of compound feeds for pregnant sows is the following:
* Energy concentrates (EC) = 75-85%
* Vegetable protein concentrates (VPC) = 10-15%
* Animal protein concentrates (APC) = 2-3%
* Mineral salts (MS) = 2-3% (from which NaCl =
0.5%)
* Vitamin-mineral premix (VMP) = 0.5-1%
With such nutritional parameters and general structure of CoF, the
requirements of pregnant sows may be covered by about 2.5 kg CoF/head/day in the
first two thirds of pregnancy and with about 3 kg CoF/head/day in the last third of
gestation.
The amounts of CoF listed above are available in thermal neutral zone (lower
critical temperature is 20oC when the sows are housed individually and 15oC when the
sows are housed in group). If the ambient temperature is lower than 10°C, the
consumption of CoF should increase by 700 g/head/day in individual housing and by
200 g/head/day in group housing. If the ambient temperature is even lower than 5°C,
the increasing of CoF intake would be 1000 g/head/day in individual housing and 400
g/head/day in group housing.
Sows during the entire gestation can be fed with a single type of CoF or with
two types.
Feeding with one type of CoF throughout entire gestation has the advantage of
simplicity.
Feeding with two types of CoF (one type in the first 2/3 of pregnancy and the
second type in the last 1/3 of pregnancy), due to changes in energy, protein and amino
acids requirements during gestation has a better scientific support.
If the sows are raised in traditional system, they are fed (also restricted) with
concentrate mixtures (maize, barley, wheat bran, peas, etc.) and volume feeds (alfalfa
flour, potatoes, sugar beet, green fodders, etc.), specifying that the share of volume
feeds in the rations DM structure can reach up to 30-35%. This possibility of feeding
determines us to return to organic pig farming.

Feeding lactating sows

The main objectives of feeding lactating sows are related to maximize milk
production (to ensure high growth rates of piglets), limiting the decrease in body
weight (to allow normal breeding activities post-weaning) and avoid wastage of feeds
(compatible with economic efficiency).
Milk production increases rapidly after parturition and typically maximizes
around days 10-14 of lactation period. Average daily milk production of sows is about
6-7 kg, with an energetic value around 1200 kcal/kg milk, which means that a sow
"export" daily milk of 7000-8000 kcal.
In lactating period (with the exception of the first week) sows should be fed ad
libitum, only so being able to cover the requirements for maintenance and for milk
production and to prevent a decrease in body weight over certain limits.
Due to high energy requirement, lactating sows even fed ad libitum cannot
consume enough feeds to cover all demands in nutritive elements. Typically, the
maximum intake cannot be reached earlier than 14 days of lactation. The result is a
weight loss, estimated at 10-25 kg, depending on prolificacy, the weight of piglets, the
length of lactation and body condition score of sows.
One of the most important issues is related to the sows feeding in the first
week of lactation, period when their appetite is lower.
If the feeds are administered ad libitum, these are not entirely consumed, and
waste is produced. So, most often in the first week after birth feeds are administered
restricted.
However, opinions differ on the degree of restriction.
There are situations where a moderate restriction is adopted. But, it was found
that in such situation, by consuming still large amounts of concentrates in the first
week of lactation, this can lead to congestion of the udder, constipation, and reduced
feeds consumption in the rest of the lactation.
There are situations in which there is adopted a severe restriction. In such
case, the deficiency of energy, amino acids, and other nutrients is pronounced.
Milk production does not decrease significantly but it will result a weight loss
of the sows (by mobilization of significant amounts of body reserves), which will be
felt later by increasing the interval between weaning and re-fertilization, generally
through bad reproductive performances. So, it's necessary an optimization.
If we talk about intensive farming of lactating sows, may be started with 3 kg
CoF/head/day in the first lactation day, then with adding additional 0.5 kg CoF for
each of the following days, so that at the maximum consumption to reach after a week
of lactation.
After the first week of lactation, sows should be fed compulsory ad libitum.
But it must be anticipated from practical reasons what the consumption will
be. This can be done based on body weight of the sows (it is given 1 kg CoF/head/day
for every 100 kg body weight) and number of piglets (it is given 0.5 kg CoF/head/day
for everyone suckling piglet).
For example, a sow weighting 200 kg and breastfeeding 10 piglets will have a
predicted average daily CoF consumption of 7 kg (2*1 + 10*0.5).
During lactation only one type of CoF can be used, in the most common
situation, with about 3000 kcal ME/kg CoF energy parameter level.
However, it is possible to adopt two types of CoF, one with a higher level of
energy parameter, towards 3100 kcal ME (at the beginning of lactation), and the other
with a lower level, towards 2900 kcal ME (in the second part of lactation, when in the
CoF structure some feeds with higher crude fibre level are included (e.g., alfalfa flour,
wheat bran, dehydrated beet pulp, etc.).
 The protein parameter level of CoF during lactation is linked to the level of
milk production (6-7 kg/day) and milk protein concentration (about 5.8%). This is
expressed in crude protein, 14-15% CP in CoF.
To achieve such energy and protein parameters, but also others, the indicative
general structure of CoF for lactating sows is the following:
* Energy concentrates (EC) = 70-80%
* Vegetable protein concentrates (VPC) = 15-20%
* Animal protein concentrates (APC) = 2-3%
* Micro-organic protein concentrates (MOPC) = 2-3%
* Fats = 2-3%
* Mineral salts (MS) = 2-3% (from which NaCl =
0.5%)
* Vitamin-mineral premix (VMP) = 0.5-1%
In addition to pregnant sows, the CoF structure also includes micro-organic
protein concentrates (MOPC) and fats.
In the extensively system, along with concentrate mixtures, lactating sows can
receive in rations also volume feeds (max. 1/3 of rations structure related to DM).
From volume feeds (in the natural form), in the winter can be used alfalfa meal (1-1.5
kg/day), potatoes or beet (3-4 kg/day) and in the summer green alfalfa, green clover,
harvested in early growing stages (5-6 kg/day).

Feeding piglets
Until weaning (which may take place on 21, 28, 35 days) breast milk is the
main nourish source for piglets. This is because the enzyme piglets’ equipment is very
different from the adults, adapted only to the digestion of lipids, proteins and lactose
from milk.
The first colostrum must be sucked 1-2 hours after birth, when it is
recommended that piglets less developed to be "directed" by the farmer to pectoral
teats, that produce more milk.
Piglets suck many times at the beginning (even 20 times/day), especially if
milk production of sows is lower.
If the milk production of sows is too low, after colostrum sub-period, piglets
can be fed with milk replacer, specifically formulated for them (reconstruct with hot
water at 180 g DM/kg, how much breast milk have) or they can be directed to sows
that are in the same period of lactation (of course, if there are many sows in the farm).
Due to rapid growth of piglets (they double its body weight about 7-8 days
after birth, with 4-5 kg milk/kg gain), only breast milk cannot cover increased piglet’s
requirements.
 Although about the effective enzymatic equipment we can speak only after 30-
35 days, since the 2nd week the piglets must consume also solid feeds.
In industrial system of pigs husbandry, piglets receive as dry feed a
“prestarter“ CoF type, consisting broadly of:
* Energy concentrates (EC) = 50-60%
* Vegetable protein concentrates (VPC) = 25-30%
* Animal protein concentrates (APC) = 5-10%
* Micro-organic protein concentrates (MOPC) = 3-4%
* Fats = 3-4%
* Mineral salts (MS) = 3-4% (from which NaCl =
0.2%)
* Vitamin-mineral premix (VMP) = 0.5-1%
Such compound feeds have about 3300 kcal ME/kg CoF and 21-22% CP in
CoF, which means very high values of energy and protein parameters.
Barley is recommended as the main energy concentrate. It is recommended to
be heat treated (by roasting in particular) for a better utilization in the piglet’s body
and to prevent the emergence of diarrhoea.
The fishmeal (or fish protein concentrate) and skimmed milk powder,
sometimes dry blood plasma, normally do not miss from animal protein concentrates.
To achieve a very high energy level in prestarter CoF for piglets there are used
fats (vegetable or animal origin).
It is estimated that in intensive system, if weaning is done at 35 days, piglets
should be able to consume about 0.4-0.5 kg prestarter CoF/head/day around weaning.
Dry feeds consumption, in fact CoF, is higher if the piglets have always access
to fresh water.
These compound feeds for suckling piglets are typically produced by
specialized companies with experience in the field, using high quality ingredients.
Creep feeding is defined as a practice of feeding piglets during the nursing
period to aid intestinal development and to facilitate the transition from the farrowing
house to the nursery house.
Creep feeding has various advantages, but it is expensive.
There is also the possibility that some special CoF to be used only in the first
few days, and then replaced with conventional prestarter CoF until weaning. This
strategy allows to piglets a very good start for growth and obviously it reduces the
cost of feeding.
In order to piglets only to have the opportunity to consume their own diet
(prestarter CoF), special nurseries are installed, to which the sows do not have access.
But piglets can circulate free among the sows, thus having access to breast milk.
 Throughout their lives, piglets may have some difficult moments, with
implication on their health status.
At about 10 days after birth anaemia frequently occurs, sometimes resulting
massive mortality, due to the low content in iron and copper of breast milk.
Although “prestarter” CoF contains these minerals, being consumed in too
small quantities, it is necessary intramuscular injection with commercial preparations,
containing the two minerals mentioned.
Towards 2-3 weeks of life, rickets may occur and also some hypo-vitaminosis
(A, D, B12). If CoF are consumed in optimal amounts the risks of such vitamin’s
deficiencies are very low.
Between 3 and 5 weeks there is a period of stress, due to reducing milk
production of sows and related to teeth rising crisis, reflected in the decreasing
consumption of dry feeds (CoF) and slowing rate of growth.
Weaning is one of the most stressful moments. Weaning is associated with
adverse effects, such as abrupt withdrawal of sow milk, low and variable feed intake,
and adapting to a new environment.
Post-weaning diarrhoea is a common problem, because the gastrointestinal
tract is still developing. Diarrhoea can reduce daily gain and in some cases it damages
the gastrointestinal tract.
To help pigs through this stressful period, supportive nutrition and care are
essential. Before, during, and after weaning it is very important to ensure that the
piglets receive a good quality diet, which will help them to cope with all the changes.

After weaning, the piglets pass in the category of youth pigs, when they are
fed with other type of compound feed ("starter“ type). In this category they remain
until entering the fattening pig’s category, namely 70-90 days of life (25-30 kg).
The change of diets, mixed to the stress of weaning and the change of
environment after weaning, can lead to what is known as the post weaning dip period.
This period of 7 to 10 days is characterized by variable feed intake, low weight gain,
and poor feeds conversion.

Feeding fattening pigs

The ultimate goal of pig’s fattening is certainly profitability. This depends on

the expenses made for a pig until the slaughter weight (from which 60-70% are
related to the feeding cost) and the price offered by the market.
Proper feeding, hybrid selection, adequate shelters, good health programs and
marketing will improve chances of profit.
 In terms of feeding, for a long time there have been used in the intensively
fattening pigs belonging to traditional breeds, two types of compound feeds: grower
type, in the first phase of fattening (from 25-30 kg to 50-60 kg) and finisher type, in
the second phase of fattening (from 50-60 kg to 100-110 kg).
But, in the last few years, new generations of hybrids have appeared, with
higher daily weight gains, with a lower share of fat in the carcasses, with other
features, which have led to the idea that the type of diets (CoF) must be changed more
frequently during fattening, about three or four times.
Changing several times of the CoF types creates the chances to a better
animal’s requirements covering (does not produce anymore a deficiency or an excess
in nutrients), which means improving productivity and feed’s costs.
In the following, for reasons of simplicity, references will be made in
particular to the two-phases fattening of pigs.
Energy parameter level of CoF for fattening pigs may be in large limits, taking
into account the ability of these animals to adjust energy consumption, when feeds
are provided ad libitum (usually case).
Mostly, energy parameter is between 3000 and 3100 kcal ME/kg CoF in the
first fattening phase and between 3200 and 3300 kcal ME/kg CoF in the second phase
of fattening.
The protein parameter level is, on average, 15-16% CP in CoF, in the first
fattening phase, and 13-14% CP in CoF in the second phase of fattening.
These levels of crude protein (and amino acids) are higher in the case of new
generations’ hybrids, which have more meat and less fat in the carcasses.
CoF are administered most often ad libitum, to allow getting higher weight
gains.
In such circumstances, on the entire period of fattening pigs consume about 2
kg CoF/head/day and toward the end of fattening about 3.5 kg CoF/head/day.
This means that, at an average daily gain (ADG) of 600-650 g, during the
whole fattening period, it results a feed conversion ratio (FCR) of 3-3.3 kg CoF/kg
gain.
It is possible that, in the last part of fattening to practice a moderate feeds
restriction (80-85% from ad libitum). The advantage is the accumulation of lower
amounts of fat in the carcasses and the disadvantage is the increasing of the fattening
period with 2-3 weeks.
To ensure optimal nutritionally parameters of CoF it is recommended the
following structure:
* EC = 70-85%
* VPC = 10-20%
 * APC = 2-3%
* MOPC = 2-3%
* Fats = 2-3%
* MS = 2-3% (from which NaCl = 0.4-0.5%)
* VMP = 0.5-1%
The way of feed’s administration can play an important role on growth
performances.
Most often, in the industrial system of fattening pigs, CoF is given in dry form
(powder or granules), this being a simpler way from a technical point of view.
The administration of wetted CoF, especially in the 2nd part of fattening, leds
to obtaining slightly better results, in terms of weight gaining obtained, FCR and
quality of the carcasses.
Also, pigs who receive wetted diets spend less time when they go to the
automatic nurseries, but they are more agitated than those which receive dry diets.
Another way of fattening pigs is that for obtaining the bacon production.
Bacon is a product obtained from ultra-specialized hybrids, with tenderness
and taste characteristics, by using a special feeding mode.
To this type of fattening there are subjected usually young animals, weighting
about 25 kg, until the slaughter weight, about 90 kg.
Feeding pigs for bacon must be made in such a way that it has to favour the
meat percentage into the detriment of fat, and the fat has to be of a certain quality.
In this respect, the protein level of CoF is higher, by 2-3 percentage points
than in the normal process of fattening pigs, and energy concentration decreases with
about 100 kcal ME/kg CoF.
Also, there are used only certain feeds, those which exercise a favourable
influence on the quality of bacon.
From the energy concentrates group, it is mainly recommended barley, that
may be the only feed from this group, possibly associated with wheat.
The maize, because it favours the accumulations of fat (and this of soft
consistency), can be introduced limited up to 20-25% in CoF structure, but only in the
first phase of fattening.
From protein concentrates there are recommended: soybean meal, peas,
skimmed milk powder (fish meal only in the first phase of fattening).
In the first phase of fattening, CoF are administered ad libitum.
In the second phase of fattening, it is practiced the moderate restriction of
feeds (about 80-85% from ad libitum) and the administration into 3-4 portions/day.