Effect of freezing extender supplementation with vitamin E on post-thawed semen quality in buck

The aim of this study was to evaluate the effects of vitamin E with glycerol as cryoprotectant on freezability of Alpine goat semen. Semen was collected from Alpine male Goat (3-4 years), twice a week for five weeks at the Animal Science Research Institute of IRAN (ASRI). Different concentrations of vitamin E (0, 0.5, 0.75 and 1 mM) in 5% glycerol as a cryoprotectant were evaluated to improve the quality parameters of goat semen. After ejaculation, semen equilibrated at 5 ºC for 2 h, and aspirated into 0.25 mL straws. After equilibration, straws were frozen in liquid nitrogen vapor and plunged into liquid nitrogen for storage. Sperm parameters, including motility and progressive motility by CASA, viability, membrane integrity and total abnormality sperm, were assessed. The results show that addition, different levels of vitamin E to the extender for freezing of goat semen can improve motility (P>0.05). Also, 1 mM vitamin E showed higher progressive motility, VSL, VCL and ALH than the other treatment groups (P>0.05). Addition 1 mM antioxidant significantly improved the viability and membrane integrity of sperm than the control group (P>0.05). Addition different levels of vitamin E to goat semen extender showed no significant difference in abnormal sperm and lipid peroxidation than the control group (P>0.05). Therefore, addition of 1 mM of vitamin E to extender improves the freezability of goat semen.