Exercise No.
1
THE EXTERNAL ANATOMY AND BODY MEASUREMENTS OF FARM ANIMALS
Introduction
Efficient animal husbandry always starts on understanding the structural
organization of the animal itself. Here comes, the anatomy (a branch of biological
science that deals with the form and structure of an organism) describing the details on
animal’s distinguishing characteristics, conditions, and etc. It aims to understand life
better, that is, to elucidate processes that constitute life. It is therefore in close correlation
with physiology (which treats the function of the different parts of the body) that is
commonly pursued more or less independently. Anatomy and physiology, however, are
both facets of the total study of the animal body. Thorough knowledge of the structure
imparts much information about its function. However, a mere description of structure
without describing function would be a little practical value. Conversely, it is impossible
to gain a thorough understanding of function without basic knowledge of the surface
involved.
The external parts of an animal body come to refer the outward declaration and/
or appearance of the animal. Thus, a practical application of the knowledge of external
anatomy (emphasis on surface form and structure) is fundamental for efficient animal
production systems. It is very important for a student in animal science to be familiar
with distinguishing external features of the different species of farm animals.
Knowledge of these parts is an important foundation for further studies in animal
science. For some, the external part is used in the identification of the sex, breed, class,
type, or species of the animal; basis for selection, judging and culling; basis for buying
and marketing stocks; and serves as basis on the determination of the animal’s condition
(whether it is healthy or not).
Learning Outcomes
1. To acquaint and familiarize students with the different terms that refers to
the specific external parts of the animal’s body.
2. To comparatively evaluate and give the different external parts of the
animal.
3. To apply the knowledge of the external anatomy in estimating the live
weight of some livestock.
Materials
Calculator
Tape measure
Live animals
Other resources
Procedure
1. The students should locate and identify the different external parts of the body in
live animals, note the similarities and/ or differences between species, breeds, sex
and age of the different farm animals that can be found within their vicinity and/ or
on internet resources.
2. In body weight estimation of farm animals, students are allowed to choose what
animal species they are going to estimate (swine, goat, sheep, and buffalo).
Students should estimate at least two animals (either same or different species) and
fill the information necessary on the table. Formulas on how to estimate the body
weight of pigs and cattle will be provided.
2.1 For Pigs
a. Body Measurement. Using a tape measure, take the heartgirth (inches)
and body length (cm) of the pig. Based on the data obtained, get the estimated body
weight (kg) of the pig using the following formulas:
W = X2 x L
400
where: W = Liveweight (lbs)
L = Body length (inches)
X = Heart girth (inches)
Note: Heartgirth = circumference of the body at the chest immediately behind the point
of the elbow.
Body Length = measured along the arc of the back from the poll (point midway
between the ears) to the base of the tail.
2.2 For large animal (cattle or carabao)
a. Body Measurement. Take measurement (cm) of heartgirth. Compute for
the estimated weight in kg
W = X2 x L
300
where: W = Liveweight (lbs)
L = Body length (inches)
X = Heart girth (inches)
ANSWER THE FOLLOWING QUESTIONS:
1. In establishing a herd and in selecting and judging, what primary
differences exist in swine as compared to beef cattle and sheep?
2. State the major differences between mature male and female of the
following animals based on their external anatomy.
Table1. List of farm animal species with its morphological differences
Morphological Differences
Species
Male Female
(Rooster/Boar/Bull/Drake/Tom/Cock) (Hen/Sow/Cow/Hen/Hen/Hen)
a. Chicken
b. Pig
c. Cattle
d. Duck
e. Turkey
f. Ostrich
3. Select at least two animal species that can be seen in your vicinity (swine,
sheep, goat, cattle, and buffalo), estimate the body weight (either same
or different species), and fill the information on the table provided below.
Table 2. Estimated body weight of farm animals
Estimated Actual Body
Animal Body Heart Girth Body Weight Weight* (kg
Species Length (in.) (in) (kg & lbs) & lbs)
Show your computation here:
