88 Plasma anti-Müllerian hormone as a marker for ovarian follicular population and oocyte quality in alpacas

Abstract

The limited success of embryonic transfer technique in alpacas is related to the high variability of superovulation protocols, the response to which depends on, among other factors, the number of antral follicles growing along a follicular wave. The concentration of anti-Müllerian hormone (AMH) is correlated with antral follicle count, making it a reliable biomarker for identifying the number of available follicles and allowing us to ensure the reproductive potential of females. Studies in different production animals exist, but, thus far, no published studies exist on the use of AMH as a biomarker in alpacas. Thus, its study is necessary in order to be able to choose the best donors for embryonic transfer, reducing response variability and unnecessary expenses in superovulation protocols. The objective of this study was to determine whether AMH is a reliable marker for the number of follicles and quality of oocytes in an induced follicular wave in alpacas. We used 52 female, nonpregnant Suri alpacas of reproductive age (3–7 years), with a body condition score between 2.5 and 3.5 (where 1 is extremely thin and 5 is obese), and with the presence of a preovulatory follicle (diameter ≥7mm) determined through transrectal ultrasound. Blood samples were collected from nonpregnant Suri alpacas 5 days post-induction of ovulation and divided into groups according to AMH concentration. AMH concentrations were then correlated with the number of follicles and percentage by sizes of follicles using the least significant difference test with adjusted means. To relate the quality of oocytes with the AMH concentration groups, a Chi-square test was used. The high-AMH group had a greater number of follicles than the low-AMH group (20.51±2.76 vs. 11.58±2.55; P=0.036). There were no significant differences between AMH groups and percentage of follicle sizes. However, the high-AMH group had a greater percentage of follicles 3- to 7-mm long (67.49%). Furthermore, the high-AMH group showed dependence on the quality of oocytes (P=0.02). These results indicate that the plasma concentration of AMH can be a reliable marker for follicle and oocyte quality in Suri alpacas. Future investigations are needed to ensure the optimal timing to collect blood samples, a kit individualized to the species, and improvement of the future donors for current superovulation protocols in alpacas.