Influence of addition of cobalamin to the extender on the post-thaw motility, viability, and DNA integrity of bovine ejaculate

Abstract

The present study was undertaken to investigate the effect of various concentrations of cobalamin (vitamin B12) in Bioexcell® extender on the spermatozoa quality of Simmental bulls. The semen was collected from 12 bulls by means of an artificial vagina. Vitamin B₁₂ at concentrations of 1.50, 2.50, 3.50, and 5.00 mg/mL was added to bovine Bioexcell® extender. The semen aliquots were cooled and preserved at 4°C. Their quality was evaluated during pre-freezing, and then the cooled semen samples were packaged into 0.25 ml straws. The straws were frozen in the vapor of liquid nitrogen, and stored at -196ºC in a container. The straws were thawed one day later, and the characteristics of spermatozoa were examined. The results showed that the effect of vitamin B₁₂ on the viability, DNA fragmentation and motility of spermatozoa was significant under both pre- and post-freezing conditions (p <0.05), and revealed that supplementation of the extender with B₁₂ improved the post-thaw spermatozoa quality in bulls.