Induction of oestrus during lactation using an injection of gonadotrophin and piglet separation

摘要

The idea of inducing oestrus in the sow during lactation is not new. Studies over the last 50 years (reviewed by Armstrong et al., 1999) have produced conflicting results when gonadotrophins were used during lactation to promote follicular growth andinduce ovulation. We speculate that these strategies were unsuccessful because 24-hour suckling activity limits the release of lutenizing hormone, which restricts gonadotrophin support for the final stages of follicle maturation and oestradiol production. The objective of this study was to prove the concept that oestrus can be induced during lactation using a combined injection of pregnant mare serum gonadotrophin (PMSG) and human chorionic gonadotrophin (hCG) at three weeks after parturition followed by piglet separation from the sow for part of the day.