HORMONAL CONTROL OF ESTRUS AND ITS EFFECT ON FERTILITY IN CYCLING EWES

Abstract

With an experiment involving 70 grade Rambouillet and crossbred ewes it was found that progesterone given orally with and without pregnant mare serum (P.M.S.), and progesterone by injection with P.M.S., resulted in appreciable estrual control in ewes. The administration of P.M.S. resulted in multiple ovulation and improved control of estrus when used in combination with progesterone given orally or by injection. Estradiol, 17-B-cyclopentyl-propionate (E.C.P.) alone, or in combination with P.M.S., gave no control of estrus, and conception rates were lowered in animals on these two treatments.