Abstract
Insemination of heifers at various intervals after ovulation with nonincubated sperm and sperm incubated in the uteri of estrous heifers for 6 to 14 hr. indicated no detectable effect of the previous exposure to uterine environment on the fertilizing capacity of bull sperm. Fertilization of ova occurred in eight heifers inseminated at 13 hr. with both types of sperm, but not at 14.5 hr, or longer except in one of four heifers bred at 14.5 hr. with control sperm. The prior exposure of sperm to estrous uteri did not result in ova fertilization in eight heifers bred after the induction of ovulation during the luteal phase. Previous uterine incubation of sperm also did not apparently influence the conception rates of heifers bred 13 hr. after ovulation. Copyright © 1966. American Society of Animal Science. Copyright 1966 by American Society of Animal Science