Effect of superoxide dismutase on cryopreservation of Mithun semen

The present study was designed to assess the effect of superoxide dismutase (SOD) on post thaw semen quality parameters (SQPs), kinetic profiles and seminal biochemical profiles in Mithun. Ejaculates (25) were split into four equal aliquots after dilution with Tris-citrate-glycerol (TCG) extender, viz. Group I (control), Group II, III and IV contained 50, 100 and 150 U/ml of SOD, respectively. Cryopreserved and thawed samples were analysed for their motility parameters (progressive forward and in bovine cervical mucus penetration test [BCMPT]), kinetic and velocity parameters by computer assisted sperm analyser (CASA), viability, sperm morphological and nuclear abnormalities, acrosomal, plasma membrane and nuclear integrities, sperm enzymatic leakage and biochemical (sperm cholesterol and antioxidant and oxidative stress) profiles. Study revealed a significant enhancement in viability, sperm morphological and nuclear normalities, acrosome integrity, motility (progressive and BCMPT), sperm cholesterol content and reduction in leakage of intracellular enzymes in Group III. Moreover, intactness of acrosome and biochemical membranes was protected significantly in addition to significant improvement in kinetic and velocity profiles in extender containing 100 U/ml SOD. These results clearly suggest that though the cryopreservation of Mithun's spermatozoa in TCG was comparable with other species but inclusion of 100 U/ml SOD holds a clear advantage over control or 50 or 150 U/ml SOD. It can be concluded that SOD supplementation in semen extender can be effectively utilized to reduce the oxidative stress and improve the antioxidant profiles with cascading beneficial effects on cryopreserved semen quality parameters in Mithun.