Antioxidant effects of bovine serum albumin on kinetics, microscopic and oxidative characters of cryopreserved bull spermatozoa

Abstract

The aim of this study was to determine the effects of bovine serum albumin (BSA) as an antioxidant on post-thaw characters of bull spermatozoa such as motion variables, viability, plasma membrane integrity, morphology, lipid peroxidation, total antioxidant capacity (TAC), total thiols (TT) and the enzymes activities. Ejaculates were collected from six proven bulls and diluted with a citrate-based extender supplemented with various concentrations of BSA (0, 0.5, 1, 1.5 and 2 g/100 mL). The results showed that the semen extender supplemented with various concentrations of BSA increased (p < 0.05) the post-thaw total motility, linearity, lateral head displacement, straight linear velocity, average path velocity, viability, hypo-osmotic swelling test, total normal morphology and normal acrosome morphology. The highest (p < 0.05) value for TAC and highest activity of catalyze was achieved by inclusion of 1 g/100 mL BSA and the highest activity of superoxide dismutase was obtained by 1.5 g/100 mL BSA in the semen extender. Total thiols were increased (p < 0.05) by supplementation of 1.5 and 2 g/100 mL BSA. No differences (p > 0.05) were detected in progressive motility, sperm track straightness, beat cross frequency, curvilinear velocity and malondialdehyde production between the experimental groups. The highest concentration of BSA (2 g/100 mL) in the semen extender reduced (p < 0.05) the sperm motion variables. The results indicated that the most effective concentration of BSA is 1 g/100 mL in the semen extender which is associated with an increase in the total motility, antioxidant enzymes activities, TT and TAC.