Superovulation and fertility in the pig

Abstract

1. The effects of gonadotrophins administered during the follicular phase of the oestrous cycle were studied in forty gilts; these were purebred Large White or Large White crosses weighing from 200-275 lb. 2. Superovulation was induced by a subcutaneous injection of PMS; half of the animals received in addition an intramuscular injection of LH. 3. All animals which received gonadotrophins exhibited normal oestrous behaviour and only four of the gilts failed to come into oestrus by Day 21 of the cycle. 4. A relationship has been established between the PMS dose and the mean ovarian response. 5. An injection of LH was not essential for ovulation after treatment with PMS. Similarly, it had no significant effect on ovarian response. 6. Egg recovery was 75% in the group of animals that exhibited fertility. Of these eggs, 93% were fertilised and undergoing cleavage.