Seasonal variations in hormones and enzymes of seminal plasma and its relationship with semen quality in crossbred cattle bulls

Present study was designed to assess the seasonal influence of seminal plasma constituents on sperm attributes in crossbred cattle bulls. Semen ejaculates were collected from 10 crossbred Karan Fries bulls at fortnightly interval during hot-humid and winter months. The seminal plasma composition (hormones and enzymes) was evaluated using standard kits. ALT, AST and ALP activities were higher during hot-humid months. Seasonal variations were not observed in testosterone and prostaglandin E-2, whereas estradiol showed a significantly higher level during hot-humid season. Moreover, testosterone and estradiol showed no correlation with sperm characteristics. Prostaglandin E-2 was negatively correlated (p < 0.05) with sperm abnormality. The enzyme levels were found to be related to semen quality attributes. AST showed significant negative correlation with mass activity, individual motility, sperm viability and a positive correlation (p < 0.01) with the abnormal sperms. ALT activity negatively correlated to mass activity (p < 0.05). A negative correlation of ALP with mass activity, sperm viability and sperm membrane integrity and positive correlation with abnormal sperm percent were also observed. It was concluded that seminal plasma enzymatic activity if coupled with conventional semen analysis parameters was better indicator of semen quality. Presence of reproductive hormones in seminal plasma did not influence the semen quality after ejaculation.