Increased fertility in young primiparous female bank voles, Clethrionomys glareolus, treated with prolactin or progesterone mating

Abstract

Fertility in yound primiparous female bank voles was improved by daily injections after mating of progesterone (0.5 mg/day) or prolactin (8 i.u./day). Prolactin treatment increased the number of healthy corpora lutea. The results suggest that the sterile mating at the start of the breeding season are not due to failure of ovulation, but to lack of progesterone from inactive CL.