Ovulation and LH secretion in the goat after intravaginal progestagen sponge—PMSG treatment

Abstract

The time and rate of ovulation, and preovulatory release of LH were examined in Angora goats after treatment with progestagen-impregnated intravaginal sponges with or without PMSG during the anoestrous and breeding seasons. The administration of PMSG was necessary to stimulate a satisfactory ovulatory response in lactating and non-lactating females, and in the anoestrous and breeding seasons. Increasing doses of PMSG increased the ovulation rate in non-lactating goats and advanced the time of ovulation in lactating and non-lactating females. The advancement of time of ovulation and of the preovulatory LH surge was most pronounced when PMSG was administered 48 h before rather than at sponge removal.