Effects of vitamin B₁₂ supplementation on the quality of Ovine spermatozoa

Abstract

The present study was undertaken to investigate the effect of various levels of vitamin B₁₂ in Tris extender on semen quality of Dallagh rams following the cooling and freeze/thawing process. Semen was collected from six healthy and mature rams with an average body weight of 60.0 ± 5.0 Kg using an electro ejaculator. High  quality samples were mixed and diluted in Tris extender supplemented with different concentrations of vitamin B₁₂ (0, 1, 2 and 3 mg/ml). The semen aliquots were cooled and preserved at 5°C and their qualities were evaluated during pre-freezing and then the cooled semen samples were packaged into 0.25 ml straws. Straws were frozen in the vapor of liquid nitrogen, and were then stored at -196ºC. Straws were thawed seven days later and the characteristics of spermatozoa were examined. Results of this study showed that the effect of vitamin B₁₂ on characteristics such as viability, motility, progressive motility and normality of spermatozoa were significant in pre and post freezing conditions (P<0.05). In conclusion, for long term storage of semen of Dallagh rams, we recommend using 2 mg/ml of vitamin B₁₂ in semen extender.

Keywords: Dallagh ram, Freezing, Semen characteristics, Vitamin B₁₂.