GONADOTROPIN INDUCED REPRODUCTIVE CYCLICITY IN DOMESTIC CAT

Abstract

Adult queens were treated with 1 of 2 sources of follicle stimulating gonadotropin (follicle stimulating hormone [FSH] or pregnant mares'' serum gonadotropin [PMSG]) to induce ovarian follicle development and estrus. Treatment involving single injections of FSH stimulated mature follicle development but resulted in inconsistent display of sexual receptivity and variable ovulation rates. Single or multiple injections of PMSG induced follicle growth, but follicle rupture often occurred prior to estrus and the mating stimulus. When compared to results obtained from queens mated while in natural estrus, cats receiving a series of FSH or PMSG injections demonstrated ovarian hypersensitivity and produced follicular cysts which failed to rupture. The most effective hormone regimen for inducing follicle growth and estrus consisted of 2.0 mg FSH injected daily i.m. until estrus. Queens receiving this treatment were capable of ovulating following mating or human chorionic gonadotropin administration and were capable of conceiving if mated.