Medicine:Boar taint
Boar taint is the offensive odor or taste that can be evident during the cooking or eating of pork or pork products derived from non-castrated male pigs once they reach puberty. Boar taint is found in around 20% of entire male finishing pigs. Skatole may also be detected in gilts, but this is linked with fecal contamination of the skin. Studies show that about 75% of consumers are sensitive to boar taint, leading pork producers to control this in order to maximize profits.[1]
Causes
Boar taint is caused by the accumulation of two compounds – androstenone and skatole – in the fat of male pigs. Androstenone (a male pheromone) is produced in the testes as male pigs reach puberty and gives the meat a urine or sweat flavour, while skatole (a byproduct of intestinal bacteria, or bacterial metabolite of the amino acid tryptophan) is produced in both male and female pigs and gives the meat a 'fecal' flavour. However, levels are much higher in intact boars, because testicular steroids inhibit its breakdown by the liver. As a result, skatole accumulates in the fat of male pigs as they mature.
Controlling boar taint
 | This section is missing information about USDA pork smelling inspection. (December 2020) |
For centuries, pigs have been castrated to prevent boar taint. Castration rates vary from country to country, and most still do not use anesthesia or analgesia when castrating pigs. Commercial farms that do castrate will do so in the pig's first week of life.
Another possible method to control boar taint is to use sex sorted semen for artificial insemination so as to produce mostly female offspring. This method has been successfully used in cattle breeding, but the technique is still under research and no economical or practical solution yet exists in pig production.
As castration has received criticism in recent years, for welfare reasons, some producers and producer associations are seeking alternative methods to control boar taint.[2] Some producers are breeding out the taint and avoiding the few breeds of pigs that are high in taint. Yorkshire, Hampshire and other lighter-colored pigs are known to be particularly low in the androstenone-based taint while Duroc pigs are high in the taint.[citation needed]
Vaccination
Vaccination against boar taint with Improvac,[3](p503) which has been used in Australia and New Zealand since 1998, is a solution[2][4][3](p503)[5] that uses the pig's immune system to control boar taint. The use of the vaccine is claimed to be as simple and reliable as physical castration in controlling boar taint. It can be administered by trained farm personnel and enables the production of pork meat that is claimed to be of high quality and to be safe for consumers to eat.[6]
The vaccine works by stimulating the pig's immune system to produce specific antibodies against gonadotropin-releasing hormone (GnRH). This temporarily inhibits testes function and thus stops the production and accumulation of boar taint–causing compounds.
By stimulating production of antibodies specific to GnRH, the vaccine stops the chain of events that lead to the release of testosterone and other steroids from the testes, including androstenone, one of the two causes of boar taint. The other major taint-causing compound, skatole, is also eliminated, because the lower steroid levels allow the liver to more efficiently metabolise it.
Each pig must be immunised twice to successfully control boar taint. The timing of the first dose is relatively flexible, but there must be a minimum of four weeks between the two doses, with the second taking place four to six weeks before slaughter. After the second dose, the boar's testicles stop growing. The handler should be trained in the use of the vaccine and the vaccinator with enhanced safety features.
The vaccine is claimed to offer an animal-friendly and a more environmentally sustainable solution to boar taint, and to allow getting benefits of natural boar growth while preserving eating quality.[7][8][9][10][11][12] However concerns about the effect of the drugs on animal and consumer health have been expressed.[13]
The vaccine will work in multiple mammalian species and is commonly used for contraceptive purposes in zoo animals and oestrus suppression in horses. The vaccine would also work to temporarily prevent sexual function in humans, but no cases of this have ever been recorded. [citation needed]
References
- ↑ Bonneau, M.; Le Denmat, M.; Vaudelet, J.C.; Veloso Nunes, J.R.; Mortensen, A.B.; Mortensen, H.P. (August 1992). "Contributions of fat androstenone and skatole to boar taint: I. Sensory attributes of fat and pork meat". Livestock Production Science 32 (1): 63–80. doi:10.1016/S0301-6226(12)80012-1.
- ↑ 2.0 2.1 "Boar Taint"
- ↑ 3.0 3.1 Meeusen, Els N. T.; Walker, John; Peters, Andrew; Pastoret, Paul-Pierre; Jungersen, Gregers (2007). "Current Status of Veterinary Vaccines". Clinical Microbiology Reviews (American Society for Microbiology) 20 (3): 489–510. doi:10.1128/cmr.00005-07. ISSN 0893-8512. PMID 17630337.
- ↑ Dunshea, F R; Colantoni, C; Howard, K; McCauley, I; Jackson, P; Long, K A; Lopaticki, S; Nugent, E A et al. (2001). "Vaccination of boars with a GnRH vaccine (Improvac) eliminates boar taint and increases growth performance". Journal of Animal Science 79 (10): 2524–35. doi:10.2527/2001.79102524x. PMID 11721830.
- ↑ Jeong J, et al "The effects of immunocastration on meat quality and sensory properties of pork loins", in Proceedings 20th Int Pig Vet Soc Cong, Durban, South Africa, 2008
- ↑ Singayan-Fajardo J, et al. "Eating quality and acceptability of pork from IMPROVAC immunized boars." In Proceedings 19th Int Pig Vet Soc Cong, Copenhagen, Denmark, 2006
- ↑ Jeong J, et al. "The effects of immunocastration on meat quality and sensory properties of pork bellies." In Proceedings 20th Int Pig Vet Soc Cong, Durban, South Africa, 2008
- ↑ Giffin B, et al. "Consumer acceptance of the use of vaccination to control boar taint is poor as it is adding one more chemical to the meat." In Proceedings 20th Int Pig Vet Soc Cong, Durban, South Africa, 2008
- ↑ Hennessy D, Newbold R. "Consumer attitudes to boar taint and immunocastration: A qualitative study." In Proceedings 18th Int Pig Vet Soc, Hamburg, Germany, 2004
- ↑ Hennessy D. "Consumer attitudes to boar taint and immunocastration." In Proceedings 3rd Asian Pig Vet Soc Cong, Wuhan, China, 2007
- ↑ Allison J. "IMPROVAC: Consumer acceptance." In Proceedings Pfizer Symposium at 20th Int Pig Vet Soc Cong, Durban, South Africa, 2008
- ↑ Lagerkvist AJ, et al. "Swedish consumer preferences for animal welfare and biotech: A choice experiment." AgBioForum 2006;9(1):51–58
- ↑ Jowit, Juliette (24 January 2010). "Fears over use of chemicals to castrate pigs". The Observer. https://www.theguardian.com/environment/2010/jan/24/pork-chemical-castration-pfizer-improvac.
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