Abstract

Eleven female California sea lions (Zalophus californianus) were administered an isolate of porcine zona pellucida (PZP) in an attempt to study the safety and efficacy of immunocontraception in this species. Each animal was given a series of three injections consisting of 65 ug PZP prepared with 0.5 ml Freund's complete adjuvant for the first injection in the series and 65 ug PZP with 0.5 ml Freund's incomplete adjuvant for the booster injections. All injections were given by hand syringe in the muscles just caudal to the spine of the scapula. All animals demonstrated rising antibody titers to soluble isolated zona pellucida (anti-SIZP). Ten of the eleven females were housed with an unproven male during the subsequent breeding season, while one female was housed with a male who had sired a pup with her the previous year. No animals became pregnant. Antibody titers will be rechecked yearly to estimate the duration of immunity. Further study is necessary to determine the safety and efficacy of immunocontraception in this species.

Figure 1. Anti-SIZP titers (% of reference serum). (N = Not tested)

Acknowledgements

ZooMontana for supplying the PZP, Dalhousie University for running the titers, and the training staff at Miami Seaquarium for their assistance.