Age-specific peripheral anti-müllerian hormone concentrations in goats (Capra hircus)

Abstract

Anti-Mullerian hormone (AMH) appears to be the best biochemical-endocrine marker in assessing the age-related decline of the ovarian follicular reserve. There is inadequate information on age-related changes in peripheral AMH concentrations in goats (Capra hircus). The present study thus aimed (i) to investigate the responsiveness of the ovary to gonadotrophin releasing hormone (GnRH) challenge to release plasma AMH into circulation in view of addressing the question whether ovarian secretion of AMH would be affected by gonadotrophic status in goats and (ii) to determine plasma AMH concentrations at different ages in goats (n= 82) using enzyme immune-assay technique. Data on hormonal concentrations in GnRH-treated animals as well as in different ages of animals were analyzed by nonparametric one-way repeated measure ANOVA and one-way ANOVA, respectively. There was no change (P>0.05) of plasma AMH concentrations after GnRH challenge in experimental goats. Plasma AMH concentrations changed significantly (P<0.05) between the mean rank of the related groups over the time (age) in goats. Plasma AMH concentration at 3 months of age was 0.36 ± 0.04 ng/ ml and thereafter it started increasing and reached ≥ 2 ng/ ml between 3 and 4 years of age and then showed a progressive decline from 5 years of age and reached at 0.30 ± 0.07 ng/ ml at 10 years of age. A cubic model was found to be the best fitted model that delineated the change of plasma AMH level with age. Hence, the present study indicated that peripheral AMH concentration could be a useful management tool for the selection of goats in breeding programmes.