Melatonin along with eCG improves fresh semen quality and plasma concentrations of melatonin and testosterone during non-breeding season in Beetal bucks

Abstract Under subtropical regions, the breeding activities of goats are restricted to a specific season. Several hormonal regimens have been used to improve reproductive performance. However, different hormonal protocols have certain limitations. The effect of melatonin + eCG therapy on fresh semen, plasma testosterone, and melatonin profiles of bucks was evaluated during the non-breeding season. Nine bucks were assigned to three treatments (control; normal saline, melatonin alone, and melatonin + eCG; n = 3 in each group). Except for control, all bucks were implanted melatonin subcutaneously and eCG was administered every fourth day to melatonin + eCG treated bucks. Weekly two fresh ejaculates per buck for 10 weeks (n = 180) were evaluated for sperm concentration, motility, kinematics (VCL, VSL, VAP, and ALH), non-viability, morphological abnormality, DNA fragmentation/damage, acrosomal and mitochondrial integrity. Weekly plasma profiles of testosterone and melatonin were monitored. From the 4th week onward, non-viable and morphological abnormal sperms and decreased (P