Chicken egg yolk plasma in tris-citric acid extender improves the quality and fertility of cryopreserved water buffalo (Bubalus bubalis) spermatozoa

Abstract

This study was primarily designed to evaluate the effect of different concentrations of ultraviolet (UV)-C–irradiated chicken egg yolk plasma (EYP; v:v; 10%, P1; 15%, P2; 20%, P3) or 20% (v:v) of whole chicken egg yolk (WCEY) in tris-citric acid (TCA) extender on water buffalo sperm quality during cryopreservation (postdilution, PD; postequilibration, PE; post-thawing, PT). Also the effect of best evolved concentration of UV-C–irradiated EYP in extender on in vivo fertility of buffalo spermatozoa was evaluated. At PE and PT, computer-assisted sperm analysis progressive motility (PM, %) was significantly higher in P3 compared with P1 and WCEY. Rapid velocity (RV, %) was higher (P < 0.05) in P3 compared with P1 and WCEY during cryopreservation (PD, PE, and PT). Average path velocity (μm/s) and straight line velocity (μm/s) were higher (P < 0.05) in P2 and P3 than WCEY at PE and PT. The decline percentage (%, longevity) in PM and RV was lower (P < 0.05) in P3 compared with WCEY during 2 hours incubation under in vitro condition at PT. Supravital plasma membrane integrity (%) was higher (P < 0.05) in P2 and P3 compared with control at different stages (PE and PT). Mitochondrial transmembrane potential (%) was higher (P < 0.05) in P2 and P3 compared with P1 and WCEY at different stages (PD and PT). Percentage of viable sperm with intact acrosome, and sperm DNA integrity (%) were higher (P < 0.05) in P2 and P3 compared with WCEY at PT. The in vivo fertility rate (%) was significantly higher with P3 compared with WCEY (76.61 vs. 64.49). In conclusion, WCEY (20%) can be replaced with UV-C–irradiated chicken EYP (20%) in TCA extender for cryopreservation of water buffalo spermatozoa.