HORMONAL CONTROL OF REPRODUCTION IN LACTATING AND NON-LACTATING ANESTROUS EWES

Abstract

Oral administration of 6-chloro-Δ6-dehydro-17-acetoxyprogesterone (CAP) and 6-α-methyl-17-α-acetoxyprogesterone (MAP) over a period of either 14 or 17 days, successfully induced estrus of lactating and non-lactating anestrous ewes. CAP was found to be more effective than MAP, at the concentrations employed (2.5 mg CAP to 40 mg MAP daily). The effectiveness of CAP and PMS in promoting predictable and early-cycling estrus in anestrous ewes was not enhanced by treatment with estradiol-17-β. Conception and lambing percentages were higher from the hormone-treated non-lactating ewes than from the hormone-treated lactating ewes.