Gonadotropin-releasing hormone immunization and castration in male pigs: effects on growth, hormonal levels, antibody titer response, testicular function, back fat, and consumers' sensory perceptions |
Panuwat Yamsakul1, Prapas Patchanee1, Terdsak Yano1, Thanawish Boonma1, Chalermchart Somkert2, Anucha Sathanawongs3 |
1Department of Food Animal Clinic, Faculty of Veterinary Medicine, Chiang Mai University 2Department of Companion Animal and Wildlife Clinic Small Animal Clinic, Faculty of Veterinary Medicine, Chiang Mai University 3Department of Veterinary Biosciences and Veterinary Public Health, Faculty of Veterinary Medicine, Chiang Mai University |
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Abstract |
This study investigated the effects of gonadotropin-releasing hormone (GnRH) vaccine on pig growth, carcass quality, and sensory perceptions of pork meat by Thai consumers. Male crossbred pigs (n = 30) were separated into three groups of 10 pigs each: boars, immunocastrated pigs, and surgically castrated pigs. The immunocastrated group was immunized at 13 and 19 weeks of age with GnRH vaccine ($400{mu}g/dose$). All pigs were slaughtered at 24 weeks of age. Blood samples were collected and testes size determined. Testes weight and back fat thickness were recorded at the time of slaughter, and meat samples were collected for sensory assessment by Thai consumers. Testosterone and progesterone concentration levels decreased significantly two weeks after the second dose of GnRH (p < 0.05), and the GnRH antibody titer of the immunocastrated pigs was significantly high two weeks after the second dose of GnRH (p < 0.05). GnRH vaccine significantly reduced the weight and size of testes. Thai consumers reported no significant differences in odor or flavor among meat samples from the three groups. In conclusion, immunocastration improved growth performance, removed the need for castration surgery, and avoided "boar taint" in the meat. It has also no distinct trace of the boar taint same as pork that is currently produced from physically castrated pig which is making it acceptable to consumers. |
Key Words:
back fat, gonadotropin-releasing hormone vaccine, growth performance, sensory assessment, testes size |
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