Effect of Hydrocortisone on Embryonic Survival in Sheep

Abstract
Two experiments were conducted in each of 2 years to determine the effect of exogenous hydrocortisone acetate (HCA) on ovum fertilization and embryonic survival in sheep. In three experiments, HCA was injected intramuscularly for 4 successive days beginning on the first day of estrus. In the remaining experiment, injections were begun about 3 days before the onset of estrus and continued through estrus. The levels of HCA used were 25, 75, 200 and 225 mg. per day. HCA had no effect on fertilization, but it significantly reduced embryonic survival in two experiments conducted during late summer and early autumn. It had virtually no effect on fertility in two experiments conducted during the winter months. Injections of L-thyroxine (0.06 mg./day) did not overcome the anti-fertility effect of HCA, and had no effect by itself on embryonic survival. Copyright © 1968. American Society of Animal Science . Copyright 1968 by American Society of Animal Science