Evaluation of Anogenital Distance and Anti-Müllerian Hormone Plasmatic Concentration as Potential Phenotypes to Predict Reproductive Performance in Holstein Heifers.

Anogenital distance (AGD) is a marker of the degree of prenatal exposure to androgens in multiple species, and it has been suggested that there is an inverse association between AGD and fertility. Therefore, the aim of this study was to determine the usefulness of AGD and anti-Müllerian hormone (AMH) concentrations, an indirect marker of the follicular population, as predictors of future reproductive potential in Holstein cattle. The AGD was measured in 566 females from 9 dairy farms in Galicia (Spain). A group of 172 females underwent a second measurement 9 months after. Additionally, data on the age at first insemination (1stAI age), number of AI (AI-PREG), age at first pregnancy (1stPREG age), age at first calving (1stCAL age), and calving-pregnancy (CAL-PREG) and calving-calving (CAL-CAL) intervals were collected. Blood samples were collected from 80 heifers to determine AMH concentrations. Our results showed that AGD varied minimally with age, and that cows with short AGD had earlier 1stAI age, 1stPREG age, and 1stCAL age (p < 0.05) than cows with long AGD. No significant differences were observed for the CAL-PREG and CAL-CAL intervals. Additionally, no significant association was found between AMH concentration and AGD or reproductive parameters. Consequently, the results suggest the possibility of using AGD as a marker of future reproductive performance in Holstein heifers. However, there was insufficient evidence to associate AMH concentrations and reproductive performance, underlining the need for further studies with larger sample sizes.