Variations in seminal parameters over a 12-month period in captive bonnet monkeys

Semen samples were collected from adult fertile bonnet monkeys twice a mont h by penile electroejaculation for twelve consecutive months. Various param eters like semen volume, weight of ejaculate and coagulum, sperm count, spe rm motility, sperm morphology, and functional parameters e.g. plasma membra ne integrity, in vitro nuclear chromatin decondensation and acrosomal statu s were evaluated to assess within and between animal variations. Effects of seasonality, if any, on quantity and quality of semen were also studied. C onsiderable intra- and inter-individual variations in the geometric mean va lues were observed for semen volume, weights of ejaculate and coagulum, and sperm counts during the study period. On the other hand, sperm motility, m orphology, and functional parameters showed less within and between animal variations. Results on motility, morphology, and functional parameters indi cated that good semen quality was maintained throughout the year. Various r outine and functional parameters did not show any annual variations. The di urnal rhythmicity in circulatory testosterone levels was observed throughou t the year. The study shows lack of seasonality in exocrine and endocrine t esticular functions and further suggests that motility, morphology, and fun ctional parameters are better indicators of semen quality in captive bonnet monkeys.