Effect of Kisspeptin Fortification in Freezing Media on Post-Thaw Quality and Fertility of Buffalo Bull Semen.

The present study was undertaken to assess the effect of kisspeptin supplementation (0.0, 5.0, 10.0, 15.0, 20.0 and 40.0 μM) in cryodiluent on freezability and in vivo fertility of buffalo bull spermatozoa. Twenty-four semen ejaculates were collected using an artificial vagina from four Murrah buffalo bulls. Ejaculates having > 70% sperm motility, < 25% morphological abnormalities and > 500 million/ml concentration were diluted with Tris-egg yolk extender containing 0.0 (control), 5.0, 10.0, 15.0, 20.0 and 40.0 μM kisspeptin and cryopreserved following established protocol. The CASA-based progressive motility and viability were higher (p < 0.05) in cryodiluent containing 20.0 μM of kisspeptin in comparison to other experimental concentrations and control. Addition of kisspeptin at 20.0 and 40.0 μM in extender exhibited higher (p < 0.05) CASA-based total motility and plasma membrane integrity. Regarding CASA-based sperm kinematics, supplementation of kisspeptin (20.0 μM) in extender improved (p < 0.05) VCL and VAP as compared to other tested concentrations and control. The acrosome integrity revealed no difference (p > 0.05) in all the experimental extenders compared to control. The MDA levels were lower (p < 0.05) in cryodiluent supplemented with kisspeptin (20.0 μM) than in other concentrations and control. Sixty artificial inseminations were performed with the post-thaw semen having the most effective dose of kisspeptin (20.0 μM) and control (30 inseminations each). The conception rates were recorded to be higher (p > 0.05) using post-thaw semen containing kisspeptin (20.0 μM; 43.3%) as compared to control (33.3%). In conclusion, complementing the cryodiluent with 20.0 μM kisspeptin improved the quality and in vivo fertility of cryopreserved Murrah buffalo bull semen.