The Cryoprotective Effects of Vitamin B12 Supplementation on Bovine Semen Quality

Contents The present study aimed to investigate the effects of vitamin B-12 supplementation on standard bovine semen quality parameters and anti-oxidative enzyme activities. Vitamin B-12 was supplemented at concentrations of 1.25, 2.5, 3.75 and 5.0 mg/ml to bovine semen cryoprotective medium. The results indicated that the motility and straight line velocity, curvilinear velocity, mean coefficient, velocity of the average path values of sperm supplemented with 2.50 mg/ml vitamin B-12 were significantly higher than that of other groups (p 0.05). The percentages of acrosome-intact and plasma membrane-intact spermatozoa were significantly improved (p 0.05). However, the catalase levels were higher in the treatment supplemented with vitamin B-12 at 2.50 mg/ml, when compared with other groups (p < 0.05). The extender supplemented with vitamin B-12 significantly decreased glutathione peroxidase activity compared with the control (p < 0.05). The supplementation of 3.75 mg/ml vitamin B-12 caused the highest value of glutathione reductase activity, compared with other groups (p < 0.05). In conclusion, the extender supplemented with vitamin B-12 could reduce the oxidative stress provoked by freezing-thawing and improve bovine semen quality. Further studies are required to obtain more concrete results on the determination of lipid peroxidation and antioxidant capacities of vitamin B-12 in cryopreserved bovine semen.