Development of soya milk extender for semen cryopreservation of Karan Fries (crossbreed cattle)

Egg yolk based semen extenders are used widely, with the potential risk of xenobiotic contamination. This study was designed to develop a soya milk based extender to substitute egg yolk based extender for bovine semen cryopreservation. In the first experiment soya milk was prepared from fresh soya bean (Glycine max). Concentration of soya milk in tris based extender was standardized based on quality parameters of spermatozoa during liquid preservation at 5°C up to 72 h and compared with egg yolk tris (EYT) extender. Sperm in soya milk tris (SMT) extender with 25 percent soya milk showed no significant (P > 0.05) differences in all the quality parameters like motility, viability, membrane integrity and acrosome integrity, as compared to sperm in EYT extender up to 72h in liquid dilution. In the second experiment the Karan Fries semen was cryopreserved in SMT extender with 25 percent soya milk (selected from the first experiment) using different concentration of glycerol, as cryoprotectant, ranging from 6-7 percent with a difference of 0.2 percent to standardize optimum concentration based on post thaw motility of spermatozoa. Glycerol at a final concentration of 6.4 percent was found to be the best among all. Further, semen samples were split and cryopreserved in newly developed SMT extender containing 6.4 percent glycerol and compared with conventional EYT extender for post thaw sperm quality parameters and degree of cryocapacitation. There were no significant (P > 0.05) differences between sperm in EYT extender and SMT extender for post thaw motility, viability, membrane integrity, acrosome integrity and cryocapacitation. In conclusion, the newly developed SMT extender maintained comparable semen quality as compared to EYT extender hence it can.