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In cattle, results of some but not other studies indicated there has been an association of circulating anti-Müllerian hormone (AMH) concentration with reproductive variables. Considering the inconsistency in results among previous studies, there was evaluation of associations between circulating AMH and reproductive performance in dairy cows, and to this end, the prevailing data of serum AMH concentration and reproductive variables were used (n = 172). Preliminarily, association of AMH concentration with reproductive indices were analyzed using linear and quadratic models. Subsequently, cows were categorized based on AMH concentrations in four equal quartiles, including cows with the least (Q 1 ; n = 43), moderately lesser (Q 2 ; n = 43), moderately greater (Q 3 ; n = 43) and greatest (Q 4 ; n = 43) AMH concentrations, and reproductive variables were compared among the respective AMH quartiles. Initially, assessments indicated reproductive variables were not linearly associated with serum AMH (P > 0.05); however, for all reproductive variables except days to first breeding service (DFS) there was a quadratic association with serum AMH (P < 0.05). Results from analysis of reproductive performance in various AMH quartiles indicated there was a longer period of DFS for cows in Q 3 than Q 1 (P < 0.05). First postpartum insemination to conception and calving to conception intervals were shorter for cows in Q 3 than Q 1 and Q 4 (P < 0.05) and for cows in Q 2 than Q 1 (P < 0.05). In conclusion, results from the present study indicate cows with intermediate AMH concentrations had greater reproductive performance., Competing Interests: Declaration of Competing Interest The authors affirm that there is no conflict of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

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

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., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Nutritional partitioning to fetal development differ among nulliparous, primiparous and multiparous cows, leading to birth of smaller calves to nulliparous and primiparous than multiparous dams. The prenatal nutritional state could influence ovarian reserve and fertility in the adult offspring. The effect of maternal parity on ovarian reserve and reproduction of female offspring, however, has not been investigated in cattle. Accordingly, a retrospective research was conducted to study reproductive variables in nulliparous- (n = 310), primiparous- (n = 236) and multiparous-born (n = 323) female offspring during the first four lactation periods in dairy cows. Additionally, anti-Müllerian hormone (AMH), as a reliable marker of ovarian reserve, was measured in a subset of nulliparous- (n = 51), primiparous- (n = 51) and multiparous-born (n = 49) female offspring. Birth weight in multiparous-born calves was greater than that in nulliparous- and primiparous-born calves (P <  0.01). Days to first service was shorter in multiparous-born female offspring as compared with nulliparous- and primiparous-born female offspring (P <  0.05). First service conception rate, proportion of repeated breeders, service per conception and calving to conception interval were greater in multiparous-born than nulliparous-born cows (P <  0.05). Cumulative culling rate was greater in primiparous-born cows than nulliparous- and multiparous-born cows (P <  0.05). The AMH concentration was greater in multiparous-born than nulliparous- and primiparous-born cows (P <  0.05). In conclusion, the present study revealed that in comparison with multiparous cows, nulliparous and primiparous cows, particularly nulliparous cows, produce female offspring with lesser reproductive performance and smaller size of ovarian reserves., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Various factors including synchronization treatments have been reported to influence sex ratio of offspring in cattle. The present study was conducted to investigate the effect of treatment with Presynch-Ovsynch protocol on sex ratio of offspring in Holstein dairy cows. Healthy Holstein cows (N = 1102) were randomly assigned to Presynch-Ovsynch (N = 564) or control (N = 538) group by parity. Cows in Presynch-Ovsynch group received two administrations of PGF(2)α 14 days apart started at Days 23 to 27 postpartum. Twelve days after the second PGF(2)α treatment, Ovsynch protocol, consisting of an administration of GnRH followed by administration of PGF(2)α 7 days later and a final administration of GnRH given 48 hours after the third PGF(2)α treatment, began. Cows were subjected to fixed-time AI 24 hours after the last administration of GnRH. Cows in control group received no treatment and were inseminated 12 hours after standing estrus. Sex of calves conceived by the first service postpartum was determined after parturition and used for calculation of sex ratio. Parity, season, sire, and calving to conception interval were considered as covariates in statistical analysis. Sex ratio of calves in Presynch-Ovsynch group (1.64) was higher than that in control group (1.09; odds ratio = 1.51; P < 0.05). Moreover, male to female ratio was higher in cows conceived in summer, fall, and winter than in cows that conceived in spring (P < 0.05). In conclusion, cows treated with Presynch-Ovsynch protocol and inseminated 24 hours after the last GnRH administration of Ovsynch had a higher sex ratio than cows inseminated 12 hours after standing estrus., (Copyright © 2013 Elsevier Inc. All rights reserved.)