Use of post-thaw semen quality parameters to predict fertility of water buffalo (Bubalus bubalis) bull during peak breeding season

This study was designed to predict the fertility of water buffalo bull using post-thaw semen quality parameters during peak breeding season. Thirty ejaculates were collected from five bulls with artificial vagina and cryopreserved. At post-thaw, semen was analysed for motility parameters, velocity distribution, kinematics, DNA integrity/fragmentation, viability, mitochondrial transmembrane potential, morphology, plasma membrane and acrosome integrity. Data of 514 inseminations were collected for estimation of in vivo fertility. Pearson's correlation coefficients showed that progressive motility (PM), rapid velocity, average path velocity, straight line velocity, straightness, supravital plasma membrane integrity, viable spermatozoon with intact acrosome or with high mitochondrial activity were correlated with in vivo fertility (r=.81, p<.01; r=.85, p<.01; r=.64, p<.05; r=.73, p<.05; r=.57, p<.05; r=.88, p<.01; r=.84, p<.01 and r=.81, p<.01 respectively). Step forward multiple regression analysis showed that the best single predictor of fertility was PM. However, combinations of semen quality parameters to predict fertility were better as compared to single parameter. In conclusion, fertility of buffalo bull can be predicted through some of the post-thaw in vitro semen quality tests during peak breeding season.