Immunocontraception of white-tailed deer with GnRH vaccine.

Abstract

Reduction of excess numbers of white-tailed deer (Odocoileus virginianus) is an example of a potential use for immunocontraception as a means of wildlife population management. A 4 year multifaceted study was conducted to determine the long term effects of gonadotropin releasing hormone (GnRH) contraceptive vaccine on the fertility and behavior of female and male white-tailed deer. Deer were monitored for breeding behavior, hormone levels, pregnancy, fawning and GnRH specific antibody levels. Treatment lead to reduced fawning rates, altered estrus behavior, reduced concentrations of progesterone, contraception and failure to maintain pregnancy following conception. GnRH immunized does bred to untreated bucks had an 88% reduction in fawning caused by either immunocontraception or immunocontragestion. The vaccine effect is reversible, directly related to the antibody titer. Infertility lasted up to two years without boosting. GnRH immunized bucks demonstrated no interest in sexual activity when paired with control females. Depending on the immunization schedule, antlers either dropped early or remained in velvet. The results of this study demonstrate that GnRH vaccine is effective in inducing a reversible infertility in white-tailed deer, the infertility lasting up to two years without boosting.