Immunocontraception of Florida Feral Swine with a Single-dose GnRH Vaccine

Problem: Methods to limit fertility of feral swine are needed to reduce transmission of diseases and agricultural and ecosystem damage. Method of Study: We evaluated a single-shot GnRH immunocontraceptive vaccine in both male and female feral swine for its effect on fertility and functional status of the reproductive tissues. Captive feral pigs were randomly assigned to receive 1000 or 2000 micrograms GnRH-KLH vaccine treatments or no treatment. Results: After 36 weeks, none of the 2000-micrograms-treated females and only 20% of the 1000-micrograms-treated females were pregnant. This corresponded to reduced serum progesterone, regressed tissues within the reproductive tract and lack of evidence for follicular development leading to ovulation. Males were less responsive to the vaccine than females, but more responsive to the lower dose of the vaccine than the higher dose. Conclusions: The single-shot GnRH vaccine is effective in controlling fertility of female feral swine and may be useful for population reduction.