LAUSR

Background: Black Bengal goat is one of the important goat breeds of India. Cryopreservation of semen and artificial insemination are effective techniques for improving goat breeding programs. Various biochemical and functional changes that occur during freezing-thawing process results in poor post thaw sperm recovery. Supplementation of antioxidants to the extender has been reported to have positive effects on semen cryopreservation in various species. The present study was undertaken to assess the effect of antioxidants butylated hydroxyl toluene (BHT), α tocopherol on post thaw in vitro sperm characters, lipid peroxide level and superoxide dismutase (SOD) activity during cryo­preservation of Black Bengal buck semen. Methods: Semen was collected from bucks by artificial vagina, antioxidant BHT was added to the Tris egg yolk extender @ 0, 1 and 2 mM/ml in control group (BHTC), treatment group 1 (BHTT1) and treatment group 2 (BHTT2), respectively. Similarly, tocopherol was added @ 0, 1 and 2 mg/ml in control group (TFC), in treatment group 1 (TFT1) and treatment group 2 (TFT2), respectively. Each antioxidant was tested with 20 semen ejaculates. Semen samples were frozen in liquid nitrogen and post freeze-thaw in vitro sperm characters, malondialdehyde (MDA) concentration and SOD activity were measured. Result: Post thaw sperm motility, functional membrane integrity and viable count were significantly (P less than 0.05) higher in the BHT and α tocopherol supplemented groups than control groups. Significantly (P less than 0.05) higher acrosome intact cells were recovered in BHTT1, BHTT2 and TFT2 groups than the control and TFT1 groups. Further, BHT supplemented groups had significantly lower level of MDA than the control, while the supplementation of α tocopherol could not control the generation of MDA. Post thaw SOD activity was found significantly lower in the antioxidant treated groups than their respective controls. It is concluded that supplementation of BHT and α tocopherol were found to be more promising in conserving in vitro sperm characters from cryo-damages during freezing of Black Bengal bucks semen.