Effect of L-cysteine Supplementation on Cryopreservation of Black Bengal Buck Semen

Abstract

Background: Black Bengal goat is one among the valuable goat breeds of India. Semen preservation and artificial insemination are practical technologies for conservation and improving livestock germplasm. Various biochemical changes that occur during cryopreservation of semen, results in loss of sperm cell structure and their functions. Inclusion of antioxidants to the semen extender has been reported to have positive effects on sperm recovery in various livestock species. The present experiment was carried out to evaluate the effect of antioxidant L-cysteine on post freeze thaw sperm characters, lipid peroxide level and superoxide dismutase (SOD) activity during cryo­preservation of Black Bengal buck semen. Methods: Twenty numbers of semen ejaculates were collected from Black Bengal bucks, antioxidant L cysteine was added to the semen extender @ 0, 1 and 2 mM in control group (CC), treatment group 1 (CT1) and treatment group 2 (CT2), respectively. Semen samples were frozen in liquid nitrogen and measured post freeze-thaw in vitro sperm characters, malondialdehyde (MDA) concentration and SOD activity. Result: Though there was no significant improvement in post thaw sperm motility, functional membrane integrity and viability count, supplementation of L-cysteine significantly improved the percentage of sperm cells with intact acrosome and significantly (P less than 0.05) reduced the level of malondialdehyde. Post thaw SOD activity was found significantly lower in the antioxidant treated groups than the control. It is concluded that supplementation of L cysteine is effective in controlling lipid peroxidation and conserving in vitro sperm characters during freezing of Black Bengal buck semen.