Relationship between Anti-müllerian hormone and superovulatory response in dairy crossbreed Holstein cows managed on grazing in the Latin American high tropics

Superovulation (SOV) has permitted to multiply animals of high genetic value; however, the average number of transferable embryos obtained has not improved in recent years. One of the factors that strongly influences is the individual variability of the donor with respect to the number of antral follicles present at the time of initiation of the SOV protocol. Therefore, the study determined the relationship and association between Anti-Müllerian hormone (AMH) and antral follicle count (RFA) at the beginning of the superovulation protocol (T0), as well as at the time of the first insemination (T9). In addition, the ovulation process was evaluated by counting the corpora lutea (CL) present on the day of washing (CL16) and the amount of structures and transferable embryos collected (day 16) in 36 lactating crossbreed Holstein cows, managed in farms from the high tropics, in extensive systems and fed to grazing. A mean concentration of 0.07 ± 0.03 ng‧ mL^‒1 of AMH was determined, an average RFA greater than 4 mm on day 0 (T0) of 14.7±4.30 follicles, with a low relationship and association between these variables (r=0.21; R²=0.04; P>0.05). In contrast, on day 9 (T9) the RFA was 16.4 ± 5.2 follicles and the relationship and association high and significant with AMH (r=0.84; R²=0.70; P<0.05). It was established that 22.2 % of the animals with high AMH presented 2.6 times more hormone, 1.8 more follicles and provided 2.5 more transferable embryos than the low AMH donors (47.2 %). In conclusion, donors with a value greater than 0.09 ng‧ mL^‒1 of AMH allow to improve the results in reproductive biotechnologies such as MOET.