Effect of beta defensin-1 on post-thaw quality of cryopreserved Barbari buck semen

Goat plays a vital role in the economy of poor and marginal farmers and very little efforts have been taken for their genetic improvement at farm level. The greatest problem still existing with the cryopreservation of goat spermatozoa is that even with the best preservation techniques available to-date, post-thaw survival is restricted to approximately 50% of the sperm population. Defensins are antimicrobial peptides and 2 beta-defensins have been identified in goat C GBD1 and GBD2). They form a coat on sperm that provides protection from recognition by immune competent cells in in vivo model system as well as when challenged with antisperm antibodies in vitro. The present study was carried out to know the effect of beta defensin-1in goat semen dilutor on post-thaw quality of Barbari buck semen. Ejaculates from Barbari bucks aged between 2–4years were collected using artificial vagina method.Immediately after collection, the volume, colour, consistency, and mass motility of ejaculates were assessedand were extended with Tris-Egg yolk-Fructose diluent having egg yolk (10%) and glycerol (6%). Beta defensin wasadded in four concentrations (0 ng/ml-control, 10 ng/ml, 20ng/ml and 30 ng/ml) in goat semen dilutor. Sperm concentrations were adjusted to 1×108 sperm/semen straw and diluted semen was equilibrated at 5°C for 4 h before being frozen. The post thaw motility (%) was 48.18±0.61, 52.15±0.57, 49.12±0.72 and 46.28±0.83 in different concentration of beta defensin (0 ng/ml-control, 10 ng/ml,20 ng/ml and 30 ng/ml), respectively. The corresponding values of live per cent sperm were 61.21±1.25, 66.53±1.55, 59.67±1.92 and 64.12±1.58, respectively. The corresponding values of acrosome integrity per cent were 68.45±1.21, 69.85±1.19, 68.38±1.26 and 63.21±1.53, respectively. The corresponding values of hypo-osmotic swelled sperm per cent were 59.48±1.79, 67.74±1.59, 61.26±1.45 and 48.18±1.38, respectively. The post thaw quality was significantly higher in 10 ng/ml beta defensin concentration than other concentrations. It can be concluded that 10 ng/ml beta defensin in goat semen dilutor can be used for routine semen freezing protocol for better post-thaw quality.