Effects of Antibodies to Steroid Hormones on Reproductive Events of Sheep and Cattle

This paper is concerned with the effect of androgen immunity on the expression of ovulation rate in the two important domestic ruminants, sheep and cattle. In the case of sheep the paper will review the development of a commercial vaccine (Fecundin®; Polyandroalbumin, Glaxo (Australia) Pty. Ltd.) which increases the numbers of lambs born to treated ewes. In the case of cattle, three experiments that have explored the ovulation rate response to active androgen immunity will be reported. The data will allow for some important comparisons to be made between the two species.