Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Department of Theriogenology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
Domest Anim Endocrinol. 2019 Jul;68:47-53. doi: 10.1016/j.domaniend.2019.01.011. Epub 2019 Feb 5.
Anogenital distance (AGD), which is an indicator of prenatal androgen exposure, has been reported to have high variability and negative association with fertility in dairy cows. Prenatal exposure to androgens could influence the development of primordial follicles and size of ovarian reserve, which is related to reproduction. However, the relationship between AGD and size of ovarian reserve has not been studied. Therefore, the present study was conducted to determine the association between AGD and circulating anti-Müllerian hormone (AMH), as an indirect marker of ovarian reserve, and to evaluate serum AMH concentration and reproductive performance in dairy cows with short and long AGD. Anogenital distance was measured 28 to 32 d postpartum, and based on the median of AGD, cows were divided into 2 subsets including short (n = 43) and long (n = 43) AGD groups. Afterward, serum AMH was evaluated on the day of estrus in cows that were estrus-synchronized. Furthermore, reproductive data of dairy cows during the previous lactation period were collected from the herd database. Concentrations of serum AMH tended to be positively associated with length of AGD, and there was a tendency for higher serum AMH concentrations in the long (634.89 ± 74.52 pg/mL) than short (451.39 ± 45.92 pg/mL) AGD group (0.05 <P ≤ 0.10). There was a tendency for more days to first service, lower first service conception rate, and higher proportion of repeat breeders in long (99.95 ± 5.34 d, 30.23% and 32.56%, respectively) than short (89.07 ± 4.97 d, 48.84% and 16.28%, respectively) AGD cows (0.05 <P ≤ 0.10). Services per conception did not differ between short (2.30 ± 0.27) and long (2.93 ± 0.29) AGD cows (P > 0.05). Calving to conception interval was prolonged in long (194.30 ± 17.12 d) than short (147.14 ± 13.11 d) AGD cows (P ≤ 0.05). In conclusion, the present study revealed elevated serum AMH concentrations and poor reproductive performance in cows with longer AGD compared with cows with shorter AGD.
肛殖距（AGD）是产前雄激素暴露的一个指标，已被报道在奶牛中具有高度的变异性和与生育力的负相关性。产前暴露于雄激素可能会影响原始卵泡的发育和卵巢储备的大小，而这与生殖有关。然而，AGD 与卵巢储备大小之间的关系尚未得到研究。因此，本研究旨在确定 AGD 与循环抗苗勒管激素（AMH）之间的关系，AMH 作为卵巢储备的间接标志物，并评估 AGD 短和长的奶牛的血清 AMH 浓度和繁殖性能。AGD 在产后 28-32 天进行测量，并根据 AGD 的中位数，奶牛分为 2 个子集，包括短（n=43）和长（n=43）AGD 组。随后，在发情同步的奶牛发情当天评估血清 AMH。此外，从牛群数据库中收集奶牛上一个泌乳期的繁殖数据。血清 AMH 浓度与 AGD 的长度呈正相关趋势，长 AGD 组（634.89±74.52 pg/mL）的血清 AMH 浓度有升高趋势，而短 AGD 组（451.39±45.92 pg/mL）（0.05<P≤0.10）。长 AGD（99.95±5.34 d、30.23%和 32.56%）的奶牛首次配种天数较长，首次配种受胎率较低，重复配种比例较高，而短 AGD（89.07±4.97 d、48.84%和 16.28%）（0.05<P≤0.10）。短（2.30±0.27）和长（2.93±0.29）AGD 奶牛的配种受胎次数无差异（P>0.05）。长 AGD（194.30±17.12 d）的产犊到配种间隔时间长于短 AGD（147.14±13.11 d）（P≤0.05）。总之，本研究表明，与短 AGD 奶牛相比，长 AGD 奶牛的血清 AMH 浓度升高，繁殖性能较差。
