THE INFLUENCE OF SERUM AND GONADOTROPINS ON INVITRO MATURATION AND FERTILIZATION OF BOVINE OOCYTES

The influence of estrous cow serum (ECS) or fetal calf serum (FCS) and their interaction with gonadotropins on in vitro bovine maturation and fertilization was evaluated. The addition of ECS or FCS to the medium significantly increased the percentage of oocyte maturation over that of Ham's F-10 medium alone (P<0.05). The addition of follicle stimulating hormone (FSH), human chorionic gonadotropin (hCG) or of FSH plus hCG to the medium provided no advantage in maturation over serum alone. However, FSH plus HCG added to the maturation medium significantly improved the frequency of pronucleus formation in both groups compared with a medium to which no gonadotropins were added (P<0.05). Both ECS and FCS (as medium supplements) promoted oocyte maturation. Although the addition of a combination of FSH plus hCG to the medium did not increase the rate of oocyte maturation, it did contribute to the high incidence of subsequent pronucleus formation. © 1990.