Effect of vitamin B12 addition to extenders on some physicochemical parameters of semen in crossbred rams

Abstract

The aim of this study was to examine the effect of different doses of vitamin B12 on some physicochemical parameters and antioxidtive enzyme activities in crossbreed rams semen during storage at 5°C. Semen samples were collected from eight crossbreed rams, evaluated and pooled at 33°C. Fresh semen was diluted with a Tris-based extender containing 0, 1, 2 and 3 mg/mL vitamin B12 and was cooled at 5°C. In both genetic group, the extender supplemented with vitamin B12 (1, 2 and 3 mg/mL) led to higher motility percentages than control group. While, the addition of 2 mg/mL vitamin B12 into the semen extenders led to higher viability sperm, in comparison to control group. In Ghezel × Baluchi genotype, the percentage of spermatozoa abnormality was reduced with vitamin B12 when compared with control group. Supplementation with vitamin B12 improved significantly sperm membrane integrity in both genotypes. Addition of vitamin B12 did not cause significant differences in the levels of superoxide dismutase (SOD) and glutathione peroxidase (GPx) when compared with the control group in both genotypes. In the current study, the addition of 2 mg/mL of vitamin B12 (as an antioxidant) to extender had higher SOD activities than the other groups in both genetic groups. In conclusion, vitamin B12 supplementation in semen extender benefit the motility and viability of crossbreed ram sperm.

Key words: Antioxidant, crossbreed ram, semen parameters, sperm, crossbreed ram.