Association of Anti-Müllerian Hormone concentrations between the pregnancy rates and pregnancy continuity of cows in different age groups

The potential relationships between Anti-Müllerian Hormone (AMH) concentrations and fertility were investigated by examining pregnancy rates and early pregnancy loss in different age groups of cows. Holstein heifers (17.35 ± 1.35 months, n = 20), young cows (3.25 ± 1.02 years, n = 20), and old cows (6.7 ± 0.80 years, n = 20) were synchronised and time fixed inseminated. A single blood sample per animal was taken during oestrus just before artificial insemination (AI), (Day 0) for the AMH analysis. The highest plasma AMH concentrations were determined in the heifer group (149.01 ± 12.62 pg/ml, P < 0.001) in the study. The AMH concentrations and conception rates decreased with age. The Day-0-AMH concentrations were higher in the pregnant animals at Day 20 after AI than in the non-pregnant animals (P < 0.05) in each group. The mean Day-0-AMH concentrations in the pregnant animals at Day 60 after AI was higher (P < 0.001) than the AMH concentrations in those with a detected pregnancy loss between D20 and D60, and also in those with a pregnancy loss and not being pregnant by Day 20 considered together. When each group was assessed on its own, based on the pregnancy results of Day 60, the Day-0-AMH concentrations were found to be significantly higher in the pregnant heifers than in the non-pregnant heifers and heifers with a pregnancy loss (P < 0.05). In conclusion, the AMH analysis might provide valuable information on the reproductive efficiency of the animals in a herd.