Effect of altering the ratio of exogenous gonadotropins on reproductive performance of primiparous sows during the seasonal infertility period

摘要

At weaning, 150 primiparous sows were assigned sequentially to receive 400?IU equine chorionic gonadotropin (eCG) with 200?IU human chorionic gonadotropin (hCG) (Gn600), or 400?IU eCG with 400?IU hCG (Gn800), or served as untreated controls. Compared with control and Gn600, the Gn800 had increased estrus response by day 7 and reduced wean-to-estrus intervals (P?P?P??0.05). Litter size was unaffected. These data demonstrate the efficacy of supplemental hCG for alleviating effects of seasonal infertility in primiparous sows.