119 Anti-Müllerian hormone as an endocrine marker of fertility in Bos taurus heifers

Abstract

The objective of the study was to determine the relationship between the serum concentration of anti-Mullerian hormone (AMH) and fertility indicators in Bos taurus heifers subjected to breeding. From a group of 40 Simmental heifers (15–18 months of age, body condition score of 5 to 7; weight 350–400kg) that received a single dose of 25mg of dinoprost, 23 females entered oestrus and were artificially inseminated 14–16h after onset of the oestrus. If the females returned into oestrus, they were inseminated until conception was confirmed by ultrasonography (30–33d after IA). On Day 4 of the oestrous cycle, a blood sample was collected from each animal, and serum AMH concentration was determined using an ELISA. The AMH levels were classified as normal (AMHn, <0.4ng mL−1) or high (AMHh, >0.4ng mL−1) and were correlated with the number of follicles (NF) and the sampling-to-conception interval (SCi). The number of follicles (antral follicles of 3 to 8mm) in each female was counted at the onset of the recruitment phase during the oestrous cycle. A linear model included AMH level as a fixed effect to analyse NF and SCi. The AMH level was correlated with NF (r=0.8; P<0.001) and SCi (r=−0.61; P<0.05). The AMHh category produced a higher NF (27±3.06 vs. 16±1.85 follicles; P<0.05) and fewer days of SCi (18.22±2.97 vs. 76.30±14.41 days; P=0.03). In conclusion, high AMH levels were related positively with the number of follicles and higher fertility in Bos taurus heifers.