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Piglet castration

Article in Biotechnology in Animal Husbandry · January 2009

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Biotechnology in Animal Husbandry 25 (5-6), p 839-847, 2009 ISSN 1450-9156
Publisher: Institute for Animal Husbandry, Belgrade-Zemun UDC 636.454

PIGLET CASTRATION

W. Migdał1, B. Živković2, Ł. Migdał3

1
Department of Animal Products Technology, Agricultural University in Krakow, Balicka Str. 122,
31-149 Krakow, Poland
2
Department of Pig Production, Institute for Animal Husbandry, 11080 Belgrade-Zemun, Autoput 16,
Republic of Serbia
3
Department of Animal Hygiene and Breeding Environment, Agriculture University, al. Mickiewicza
24/28, 30-059 Kraków, Poland
Corresponding author: wmigdal@ar.krakow.pl, wmigdal@bochnia.pl
Original scientific paper

Abstract: PIGCAS is the acronym of the project “Attitudes, practices and

state of the art regarding piglet castration in Europe” is to our knowledge the first
project that has focused on castration practice across European countries plus
Norway and Switzerland. About 250 million pigs are slaughtered in Europe each
year. Of the 125 million male pigs, approximately 20% are left entire, less than 3%
are castrated with anaesthesia and the rest is castrated without anaesthesia.

Key words: castration, pig

Introduction
Castration of animals has been under debate for many years. In animal
breeding castration has been performed on animals intended for fattening with the
purpose of removal of boar taint or tranquilizing animals temper (gelded horses,
bullocks). Castration was (in some countries still is) performed on females. Non-
conventional production system in Spain and Portugal prefers castration of all
piglets (including gilts). In Spain, on farms, 75% of gilts are castrated at the age of
30 – 50 days (average 35) by vet. In Portugal regards it non-conventional
production of Alentejana’s breed. Breed is represented by about 12000 sows and
1200 - 1500 boars. This is primitive, slowly growing breed, slaughtered in 20
months of life. Because meat of non-castrated pigs characterizes negative smell and
taste, also gilts are castrated in 90 (50-120) day of life. According to scientists
castration in this breed is performed without anaesthesia (Migdał et al., 2008).
In breeding of most livestock castration has been abandoned, and till today
names of castrated animals remain:

• bullock – castrated bull

• wether – castrated ram
840 W. Migdal et al.

• billy goat - castrated buck

• capon, gelded cock – castrated cock

Presently, because of breeding practise castration is performed on stallions

(gelded horse – castrated stallion) and young boars (barrow, castrated boar). The
aim of this procedure is tranquilize temper (stallions) and remove negative meat
odour in fact fat odour – sex taint (boars). In European Union castration by any
other way then tearing the tissues, without anaesthesia is allowed till 7 day of
piglet’s life (Directive 2001/93/WE). In other cases castration can be performed
only by vet with anaesthesia. In Swiss from 2009 surgery castration without
anaesthesia, regardless of piglet’s age is prohibited. In Norway this restriction is
slowly implement and fully ban surgery castration till 2015. In United Kingdom
and Ireland generally castration of male piglets is not performed. Young boars are
full value pigs of slaughter. It should be taken into consideration that one of the
lowest weight of fatteners slaughtered in Europe is in this countries – Great Britain
– 76,6 kg, Ireland 74,0 kg (Annual Report, EUROSTAT, PIGCAS). . According to
dates provided by responders in PIGCAS project 81 -82 % of male piglets are
castrated in Poland. It seems that this dates are underestimated, because only in
reproduction farms male piglets aren’t castrate and percentage part of reproduction
farms in Polish pig’s industry are lower then 19%. In many European countries
minority of male piglets is castrated – Cyprus (38-39%), Portugal (11-12%) and in
Spain (33–34%). Meat from castrated boars in those countries is exported or used
to production of high quality products. Also in Greece 24% of boars are not
castrated. Some ecological production systems prefer growing entire males e.g.
„Milieukeur” in Netherlands (Migdał et al., 2008). PIGCAS project showed that in
Europe we have three groups of variations in attitudes and practices:
- Great Britain, Netherlands, Greece, Finland and Ireland are oppose pigs castration
- Spain, France, Austria, Denmark, Sweden, Swiss, Norway, Estonia, Slovenia,
Poland, Germany and Lithuania are indecisive in this case.
- Cyprus, Italy, Slovakia, Hungary, Belgium and Latvia are countries which opt to
use castration (Migdał et al., 2008).
Unpleasant meat smell for consumers, often is the reason for
disqualification its suitability for human consumption are well known for farmers.
The use of fishery products like oils, meal into compound for pigs and poultry in
final period of fattening may be cause of “fishy taint in pork meat”. Products from
oilseed rape (meal from full seeds and solvent extraction, oils) may cause
characteristic rape taint of animal products. Smell of beef or lamb meat may be
changed by certain green fodder (clover), beet. Administration of drugs before
slaughtering may have negative effect on meat flavour and taste, which is not
accepted by consumers.
 Pig castration 841

Table 1. Statistics on number of pigs slaughtered in EU, and selected other countries (Numbers
are millions of heads) 2002-2006 (Report of PIGCAS, 2008)

Total 2002 Total 2003 Total 2004 Total 2005 Total 2006
(Millions) (Millions) (Millions) (Millions) (Millions)
Austria 5.4 5.4 5.4 5.3 5.4
Belgium 11.1 11.3 11.1 10,9 10.7
Bulgaria 3.2 1.0 1.0 0.9
Cyprus 0.7 0.7 0.7 0.7 0.6
Czech Republic 4.5 4.4 4.1 3.8 4.0
Denmark 22.4 22.5 22.9 22.9 21.4
Estonia 0.5 0.5 0.5 0.5 0.4
Finland 2.1 2.3 2.4 2.4 2.4
France 26.6 26.5 25.3 24.9 25.5
Germany 44.3 45.4 46.9 48.3 50.1
Greece 2.2 2.2 2.2 2.2 2.0
Hungary 6.6 5.4 5.2 4.9 5.2
Ireland 3.1 2.9 2.7 2.8 2.7
Italy 13.3 13.6 13.6 13.0 13.4
Latvia 0.5 0.5 0.5 0.5 0.5
Lithuania 1.1 1.3 1.3 1.4 1.3
Luxemburg 0.1 0.1 0.1 0.1 0.1
Malta 0.1 0.1 0.1 0.1 0.1
Netherlands 15.4 13.9 14.3 14.5 14.0
Poland 23.0 25.3 23.1 22.5 24.3
Portugal 5.1 5.2 5.0 5.1 5.4
Romania 5.3 6.3 4.6 4.4
Slovak Republic 2.1 2.0 1.8 1.5 1.3
Slovenia 0.7 0.8 0.9 0.9 0.4
Spain 37.0 38.2 37.8 38.0 39.3
Sweden 3.3 3.3 3.4 3.2 3.0
UK 10.6 9.4 9.2 9.2 9.1
Norway 1.3 1.3 1.5 1.5 1.4
Switzerland 2.7 2.6 2.6 2.7 2.9

Fundamental problem is boar taint, caused by high concentration of

androsterone and skatole. In 1968 Patterson diagnosed androsterone -5-alfa-
androst-16-en-3-on, urine-smell compound, produced in Leydig’s cell of testis,
responsible of specific meat smell – boar taint. Androsterone is pheromone,
chemically similar to testosterone. Maximum concentration of fat 3-8 μg/g occurs
842 W. Migdal et al.

in 240 day of life and then it is reduced to 1 μg. If we take into consideration the
consumption suitability of castrated boars meat :
• concentration lower then 0,5 μg of androsterone in 1 g of fat – carcass
without boar taint
• 0,5 – 1,0 μg of androsterone – moderate contamination of carcass – boar
taint is eliminated after primary meat treatment
• Higher then 1 μg of androsterone – sensible smell – disqualification of
carcass (Bonneau and Sellier, 1986; Bonneau et al. 2000).

Table 2. Mean carcass weight of pigs slaughtered in EU, and selected other countries 2002-2006
(Report of PIGCAS, 2008)

Country 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
Austria 91.5 94.5 97.5 98.7 92.4 93.9 95.6 95.4 95.4 95.8 94.2
Belgium 93.8 94.2 93.7 91.02 94.8 93.1 93.9
Belgium/Luxemb. 92.2 92.2 93.1 94.4
Luxembourg 71.5 91,6 94.7 95.1 94.7 94.5 94.4
Denmark 75.7 76.5 77.7 77.1 77.5 78.5 78.6 78.3 79.0 78.6 81.2
Finland 81.8 82.0 83.8 83.7 84.2 85.1 85.8 84.3 84.3 84.8 83.3
France 85.0 86.2 87.1 86.4 85.9 87.5 88.2 88.1 90.5 90.7 88.8
Germany 91.9 92.4 92.7 92.0 92.1 92.5 92.8 93.4 92.2 93.3 94.0
Greece 59.9 60.6 60.0 63.3 63.6 61.4 49.3 50.7 62.6 62.6 61.7
Ireland 72.1 71.7 71.3 71.6 73.1 74.0 74.3 75.6 75.9 75.5 74,0
Italy 118.1 114.8 112.3 113.3 114.4 114.8 115.7 117.0 117.0 116.4 116.6
Netherlands 87.9 89.8 89.5 87.5 87.4 91.2 89.4 90.2 89.9 90.1 90.2
Portugal 71.0 65.5 66.5 66.2 64.9 65.7 64.6 62.8 62.6 63.6 63.0
Spain 81.3 80.6 79.8 81.1 81.8 82.4 82.9 83.5 81.3 81.5 81.2
Sweden 83.0 84.1 85.3 85.7 85.2 86.3 86.5 87.0 87.5 87.1 86.1
UK 70.3 70.4 70.6 70.8 70.8 73.1 73.2 76.4 76.9 77.0 76.6
Bulgaria 72.1 73.1 73.2 74.2 73.6 77.0 76.6 69.4 78.6 78.8
Cyprus 78.6 79.1 80.3 80.7 81.1 78.7 79.6 79.3 79.6 80.3 81.1
Czech Republic 81.6 80.8 81.9 83.7 95.5 96.7 94.3 93.2 95.1 92.5 87.9
Slovakia 105.0 107.5 104.4 94.0 73.1 72.5 73.9 92.1 91.8 92.3 86.4
Estonia 62.9 70.5 71.5 70.2 72.3 73.9 73.2 72.8 75.9 79.0 74.3
Hungary 90.9 94.4 94.8 97.6 96.9 98.7 88.2 94.7 93.7 92.3 93.0
Latvia 82.8 81.8 81.2 72.8 76.9 77.3 78.6 73.6 75.2 76.9 78.0
Lithuania 82.0 78.4 81.3 85.7 87.3 85.9 83.9 72.1 73.4 78.1 78.9
Malta 75.6 80.0 83.9 82.4 74.8 80.6 82.0 80.7 81.1 81.1 79.3
Poland 87.8 87.1 87.3 83.7 84.9 84.2 87.8 86.6 84.7 86.8 85,5
Romania 75.3 80.2 88.2 86.3 87.2 87.9 89.6 84.5 81.6 90.0
Slovenia 87.4 72.8 84.0 83.6 82.2 82.9 84.8 78.2 83.6 81.6 86.0
Norway 80.8 78.4 80.0 77.7 75.7 76.3 78.3 79.4 77.8 76.7 76.5
Switzerland 82.7 84.3 84.6 84.3 85.2 84.8 85.9 86.7 87.1 86.7
 Pig castration 843

Second compound linked with boar taint is scatole (3-methylo-indol),

which is synthesized in large intestine as product of degradation of tryptophan by
intestine bacteria. Scatole is absorbed from intestines or by skin if environment is
polluted by excrements. Gilts and castrated boars remove scatole from organism by
liver. Boars sex hormones reducing metabolism of scatole, that is why
concentration of scatole in carcass is higher. Only by nutrition changes scatole can
be limited in meat. (Bonneau and Sellier, 1986; Bonneau et al., 2000).
Depending on breed, line 8 – 75% puberty males are affected by boar taint.
But researches showed that boar taint is present in gilts and castrated boars. Duroc
breed has highest concentration of androstenone, while Large White breed has
highest concentration then Landrace breeds. Coefficient of inheritance is between
0,25 – 0,87 depending on breed, line and research team (Tuz, 2008). Androstenone
is also synthesized in adrenal gland cortex and ovary, so boar taint occur also in
gilts and castrated boars (Andersson, 1995; Paschma et al., 1998). Because
androstenone is lipophilic and occur (except submandibular glands) in fat, adiposis
animal can be characterized by higher intensity of boar taint. Especially during heat
treatment boar taint can be sensible (roasting, frying, boiling). Intrestingly, when
informing panelist that he judge boar meat, percentage of negative assessment of
smell and taste is increased. Cheat consumer that he judge boar meat (instead of
this we provide gilts or castrated boars meat) also increase negative assessment.
Testis notice during slaughter also has influence on negative assessment. Most
reliable method of boar taint detection are HPLC/FL or ELISA test (Tuz, 2008).
Consumer’s assessment by sensory panel is subjective, often wrongly, because
smell sensibility of every human being is different. According to Bonneau (2000)
number of consumers dissatisfied from boar meat’s smell is about 6,5 % higher
then dissatisfaction from gilts meat. Lowest different taste and smell was observed
in Great Britain. Moreover it was found that scatole was more sensible, while
androstenone’s detection depended of smell sensitivity of panelist. 25% of men and
16 – 16% of women don’t detect androstenone, but there is huge diversification
between cultural and countries (Gilbert and Wysocki, 1987). In Germany and Spain
significant more people do not detect androstenone then in Great Britain,
nevertheless in Great Britain boars are not castrated and this is no problem for
consumers. It seems that boar taint problem is rather created by media, therefore
from many years there are carried out experiments leading to remove or limit boar
taint of meat. This including keep up and fattening young boars (Great Britain and
Ireland) was hard to introduce in Poland because meat industry prefer heavy
fatteners for ham production. This method can be genetic selection and breeding
lines of boars not affected by boar taint (boar taint of meat is in 8 – 75% puberty
boars). Sperm sorting is considered as a very good solution for the long term.
Chemical castration by potassium tetraoxomanganate (VII), lactic acid, acetic acid,
zinc and silver salts is effective but can cause inflammation of testis and whole
844 W. Migdal et al.

scrotum. Till 1998 in Australia and New Zealand boars vaccination is way to
eliminate boars taint of meat. Nowadays vaccinations against boar taint are used
in Brazil, Chile, Mexico, Korea and South Africa and recently also in Swiss.
Vaccination against boars taint frequently is called “immunocastration”,
cause controversy amongst consumers because of name. “Immunocatration”
among common people suggest using hormone. In reality this method work by
administration of analogue of gonadotrophin releasing factor. Analogue bound
with protein carrier determinate antigen function. In Australia, New Zealand ther
are using long – absorbing implants produced by Peptech, including deslorelin –
synthetic analogue of GnRH. Similar implants were used in by Tuz (2008) with
conclusion that “ freeing from implants agonist of GnRH (deslorelin) cause
stoppage of testis development and accessory glands and lower concentration
androgens to level guarantee elimination of boar taint from carcasses. Similar
working Suprelorin was allowed to use by European Commission on whole
European Union. Research from Sweden (Einarsson et al., 2002) showed full
efficiency of this vaccine and good quality of boars meat. Moreover for the
Swedes pork after immunocastration has better quality then after surgical
castration. In Swiss two to three consumers rate pork after immunocastration
higher then from surgical castration. Opponents of this method are afraid of
accidentally self-injection, for them problem is time-consumption of this method
(two times injection) and it’s complication, but final decision will depend on costs
of this vaccine and breeders acceptation, which know best about benefits from
entire boars rising. Entire boars are higher growth rate (4,5-14%) comparing to
castrated boars, lower (6,6-9,5%) feed consumption, better (7,5-14%) use of feed
for gain 1kg body weight, lower (4-20%) content of fats, beneficial tissues profile
and higher stress resistance. It should be taken in consideration that meat is less
tenderness, higher concentration of unsaturated fatty acids – mainly linoleic acid,
less resistance for PSE and DFD and higher aggression during transport to
slaughterhouse (fights between males) (Tuz, 2008).
Using of vaccinate against boar taint, which is incomplete analogue of
gonadotrophin releasing factor bound with protein carrier allow breed fatteners –
boars without boar taint. Vaccinate stimulating immunological system to produce
specific antibodies against endogenous releasing GnRF from hypothalamus.
Specific antibodies neutralizing gonadothrophin releasing factor, which block
releasing LH and FSH hormone. Testis functions are blocked (testis size decreasing
twice or threefold comparing to not vaccinated boars) as well as pheromones
production. So far in research vaccinate was used in two dose, with 4 weeks break
at least, in dorsal part of neck, just behind auricle with the aid of special applicator.
Date of first vaccination is optional but second must be performed 4-6 weeks
before slaughter. During this time liver removing substances responsible for boar
taint. Lack of boar taint can be noticed 2 weeks after second vaccination and
 Pig castration 845

upkeep for about 8 weeks. After this period testis size and functions are working
like before vaccination. There is no waiting period (Lundström and Malmfors
1993). ). Researches from Sweden (Lundström and Malmfors, 1993), Spain (Font-
i- Furnols et al., 2008) earlier in Australia and in USA (Dikeman, 2007) shown
efficiency of vaccine and good meat quality.
Highly interesting connected with boar taint, or lack if it are Naravé pigs
from Oceania, they have handicapped enzymatic pathway of steroid hormone
production. This defect manifested itself in phenotype, while they are
hermaphrodites. During fattening they are recognize as males but meat is free from
boar taint, because they are lacking testicular hormones and males pheromones.
These pigs have high slaughter value for natives.

Kastracija prasadi

W. Migdał, B. Živković, Ł. Migdał

Rezime

PIGCAS je akronim projekta “Attitudes, practices and state of the art

regarding piglet castration in Europe - Stavovi, praksa u vezi sa kastracijom
prasadi u Evropi”, i to je prvi projekat koji se fokusira na praksu kastracije u
evropskim zemljama uz Norvešku i Švajcarsku. Oko 250 miliona svinja se zakolje
u Evropi svake godine. Od tog broja 125 miliona su nerastovi, 25% je netaknuto,
3% je kastrirano uz anesteziju, a ostatak bez anestezije 20% are left entire, less than
3% are castrated with anaesthesia and the rest is castrated without anaesthesia.

References

ANDERSSON H., LUNDSTRÖM K., RYDHMER L., HANSSON I., FORSBERG

M. ANDERSSON K. (1995): Effects of spring and autumn light regimens on
puberty, boar taint and leanness in entire male pigs. In: , 4. Annual report:
Classification and weight results, Animalia, Norway
BONNEAU M., SELLIER P. (1986): Fat androstenone content and development
of genital system in boars. World Rev. Anim. Prod., XXII 1, 2-30.
BONNEAU M., LEDENMAT M., VAUDELET J.C., VELOSONUNES J.R.,
MORTENSEN A.B., MORTENSEN H.P. (1992): Contributions of fat
androstenone and skatole to boar taint: I. Sensory attributes of fat and pork meat.
Livest. Prod. Sci., 32, 63-80.
BONNEAU M., LUNDSTRÖM K., MALMFORS B. (1997): Boar Taint in Entire
Male Pigs Wageningen Pers, Wageningen, pp. 70-73 EAAP Publication No. 92.
846 W. Migdal et al.

BONNEAU ET AL. (2000): An international study on the importance of

androstenone and skatole for boar taint. IV. Simulation studies on consumer
dissatisfaction with entire male pork and the effect of sorting carcasses on the
slaughter line, main conclusions and recommendations. Meat Science, 54, 3, 285-295.
DIKEMAN M.E. (2007): Effects of metabolic modifiers on carcass traits and meat
quality. Meat Sci., 77, 121-135.
DYREKTYWA KOMISJI 2001/93/WE z dnia 9 listopada 2001 r. zmieniająca
dyrektywę 91/630/EWG ustanawiającą minimalne normy ochrony świń (Dziennik
Urzędowy L 316 , 01/12/2001 P. 0036 – 0038);
EINARSSON S., ANDERSSON K., ZAMARATSKAJA G., WALLGREN M.,
RODRIGUEZ-MARTINEZ H., RYDHMER L., ANDERSSON K.,
LUNDSTRŐM K. (2002): Swedish trials with immunocatration of boars. Science.
EUROSTAT
FONT I FURNOLS M., GISPERT M., GUERRERO L., VELARDE A., TIBAU
J., SOLER J., HORTÓS M., GARCÍA-REGUEIRO J.A., PÉREZ J., SUÁREZ P.,
OLIVER M.A. (2008): Consumers’ sensory acceptability of pork from
immunocastrated male pigs. Meat Science, 80, 4, 1013-1018
FREDRIKSEN B., FONT I FURNOLS M., LUNDSTRÖM K., MIGDAL W.,
PRUNIER A., TUYTTENS F., BONNEAU M. (2008): Practice on castration of
piglets in Europe. Animal, 1-8, 2009.
GILBERT, A.N., WYSOCKI C.J. (1987): The Smell Survey Results, National
Geographic 122, 514- 525.
LUNDSTRÖM K., MALMFORS B. (1993): Skatole levels as affected by
inheritance and season. In: , p. 6 File: S2P13.WP.
LUNDSTRÖM K., MALMFORS B., MALMFORS G., PETERSSON H., STERN
S., MORTENSEN A.B., SØRENSEN S.E. (1984): Boar taint and bitter taste as
affected by androstenone and skatole, 397-398.
LUNDSTRÖM K., MALMFORS B., FJELKNER-MODIG S., SZATEK A.
(1983): Consumer testing of boar meat in Sweden, Swedish Journal of Agricultural
Research, 13, 39-46.
LUNDSTRÖM K., MALMFORS B., MALMFORS G., STERN S., PETERSSON
H., MORTENSEN A.B., SØRENSEN S.E. (1988): Skatole, androstenone and taint
in boars fed two different diets. Livest. Prod. Sci., 18, 55-67
MIGDAŁ W., FREDRIKSEN B., BONNEAU M., PRUNIER A., OUEDRAOGO
A., OLIVER M.A., FONT I FURNOLS M., LUNDSTRÖM K., TUYTTENS F.,
EDWARDS S., VON BORELL E., DE ROEST K., KUPPER T., PAŚCIAK P.,
MIGDAŁ Ł. (2008): Kastracja prosiąt w Europie. Trzoda Chlewna, 5, 88-93
PASCHMA J., PŁONKA S., SABOR M., KOŁAT S. (1989): Porównanie
wyników tuczu knurków i kastratow ubijanych przy różnej masie ciała. Rocz.
Nauk. Zoot., 16, 1, 143-153
 Pig castration 847

PATTERSON R.L.S. (1968): 5α-Androst-16-ene-3-one: Compound responsible for

taint in boar fat. J. Sci. Food Agric., 19, 31-38
PIGCAS http://w3.rennes.inra.fr/pigcas/index.htm
REPORT OF PIGCAS WP2: Practice. Assessment of the extent of the practice of
castration and how it is performed in different European countries
TUZ R. (2008): Zapobieganie występowaniu zapachu płciowego w tuszach
niekastrowanych chirurgicznie knurków. Rozprawy 446. Zeszyty Naukowe AR w
Krakowie, z. 323.

Received 31 May 2009; accepted for publication 15 August 2009

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