Determination of Antimüllerian Hormone Levels and its Relationship with the Number of Follicles and Ovary Size in Heifers and Adult Brahman Females

The study was carried out in the central coast region of Ecuador, municipality of Paján, province of Manabí. The objective was to determine the functional relationship between the levels of Antimüllerian Hormone (AMH), follicle count, age of the individual and ovary size of Brahman females. Sixty (60) bovine females aged between 18 and 132 months were randomly selected from a high genetic value Brahman cattle population and were subjected to gynecological examination using ultrasonography to verify ovarian activity. In addition, an ovulation synchronisation protocol was performed on all the females. Blood samples were taken for determination of serum AMH levels by an ELISA test using MOFA® kits for the analysis of samples. Follicle count and size of the ovary were evaluated through endorectal ultrasonography. The data and the relationship between the variables under study were examined through regression analysis. Plasma levels of AMH decreased with age of the individual; an inverse linear adjustment was obtained between AMH levels and age and among small follicles, total follicles and age, showing signs of depletion of the ovarian reserve over time. We observed a direct linear relationship between ovary size and follicle count.