Department of Animal Reproduction, FMVZ - USP, São Paulo, Brazil.
Cargill Animal Nutrition, Campinas, Brazil.
Reprod Domest Anim. 2020 Jun;55(6):753-758. doi: 10.1111/rda.13677. Epub 2020 Apr 30.
This study evaluated the association between plasma anti-Mullerian hormone (AMH) concentration and fertility in Nelore (Bos indicus) heifers submitted to timed artificial insemination (TAI). At the onset of the synchronization protocol, heifers (n = 289) received a subcutaneous P4 ear implant (3 mg) and 2 mg of oestradiol benzoate. Eight days later, the P4 implant was removed and 0.5 mg of oestradiol cypionate, prostaglandin (0.265 mg, i.m.) and equine chorionic gonadotropin (300 UI, i.m.) was administered, and TAI was performed 48 hr after ear implant removal. Ovarian ultrasound evaluations were performed to measure number of ovarian follicles, dominant follicle size and ovulation response. Pregnancy diagnosis was performed by ultrasound 30 days after AI. Heifers with greater circulating AMH had more antral follicles, a smaller dominant follicle near timed ovulation and lower ovulation response to the timed AI protocol compared to heifers with lower circulating AMH. Although AMH and pregnancy outcome had a quadratic-shaped pattern, AMH was not significantly associated with fertility. In conclusion, heifers with lower AMH had larger follicles towards the end of the synchronization protocol and greater ovulation responses, whereas greater circulating AMH was unrelated to conception success.
本研究评估了血浆抗苗勒管激素（AMH）浓度与接受定时人工授精（TAI）的尼洛牛（Bos indicus）小母牛生育力之间的关系。在同步方案开始时，小母牛（n=289）接受了皮下 P4 耳植入物（3mg）和 2mg 的苯甲酸雌二醇。8 天后，取出 P4 植入物，并给予 0.5mg 的己酸雌二醇、前列腺素（0.265mg，肌内注射）和马绒毛膜促性腺激素（300UI，肌内注射），并在耳植入物取出后 48 小时进行 TAI。进行卵巢超声评估以测量卵巢卵泡数量、优势卵泡大小和排卵反应。人工授精后 30 天通过超声进行妊娠诊断。与循环 AMH 较低的小母牛相比，循环 AMH 较高的小母牛在定时排卵时具有更多的腔前卵泡、较小的优势卵泡和较低的排卵反应对定时 AI 方案。尽管 AMH 和妊娠结局呈二次曲线模式，但 AMH与生育力无显著相关性。总之，在同步方案结束时，AMH 较低的小母牛具有更大的卵泡和更大的排卵反应，而较高的循环 AMH 与受孕成功无关。
