EN
The present study was designed to compare egg yolks from three avian species in extender for cryopreservation of Sahiwal bull epididymal spermatozoa. The study was conducted on cauda epididymal spermatozoa from ten slaughtered Sahiwal bulls. Semen retrieved from epididymal cauda of each testes pair was pooled and diluted in tris-citric acid-glycerol extender containing either pigeon, guinea fowl or chicken egg yolk semi colon leading to a final spermatozoal concentration of 30×106 ml-1. Diluted semen was transferred into 0.5 ml straws, cooled to 4°C and equilibrated for 4 h. The straws were kept on liquid nitrogen vapours for 10 min and then plunged into liquid nitrogen for storage. Motility, plasma membrane integrity and spermatozoa morphology (acrosome ridge;head, mid piece and tail) of each diluted semen sample were assessed at 0, 2 and 4 h post-thawing.All indicators applied and acrosomal integrity were the highest (P<0.05) after freezing in extender containing pigeon egg yolk compared to guinea fowl and chicken egg yolk 0, 2 and at 4 h postthaw.Moreover,spermatozoa tail abnormality percentages were also significantly lower (P<0.05) in extender containing pigeon egg yolk compared to guinea fowl and chicken egg yolk at 0, 2 and 4 post-thaw h. In conclusion, pigeon egg yolk used in semen extender improved the post-thaw quality of Sahiwal bull epididymal spermatozoa.