STUDIES ON THE HORMONAL CONTROL OF ESTROUS PHENOMENA IN THE ANESTROUS EWE

Publisher Website
Google Scholar
Abstract
THE NONPREGNANT EWE of most mutton breeds has a sexual season of approximately 6 months followed by an anestrous period of equal duration. Some breeds such as the Merino, Rambouillet and Dorset Horn have a shorter anestrus. Environment may also influencethe onset of the sexual season. During anestrus an opportunity is afforded to study the mechanism of control of estrous phenomena not furnished in polyestrous animals, except inthe infantile and, in some instances, the lactating animal. Perhaps the situation is morecomplex in semipolyestrous animals such as the ewe. Conceivably the onset of anestrus may be related to the development of inhibitory substances not encountered in polyestrous animals. The induction of estrus, in that instance, might depend upon the neutralization or overriding of an inhibitory substance rather than simply the direct stimulation of thereproductive organs. Earlier studies (Cole and Miller, 1933 and 1935) on the induction of estrus in anestrous ewes with equine gonadotropin.