Prediction of fertility based on frozen-thawed seminal traits in Sahiwal bulls

Abstract

The present investigation was carried out to predict the fertility of bulls on the basis of post-thawed seminal traits and in vitro fertility tests using deep frozen semen straws and conception rate of Sahiwal bulls maintained at the institute. The overall least squares means for post-thaw motility, non-eosinophilic sperms, abnormal sperms, hypo-osmotic swelling reacted sperms and acrosomal integrity were 56.47±0.48, 57.60±0.93, 12.13±O.14, 52.66±0.79, and 55.79±0.85, respectively. The overall least squares means for computer assisted semen analysis parameters like per cent motility (%), straight line velocity (µ/sec), curvilinear velocity (µ/sec), mean linearity (%), lateral head displacement (µ) and velocity of average path (µ/sec) were 60.17±1.24,42.03±1.05, 92.74±2.51, 59.39±1.50, 6.99±0.24 and 64.84±1.50, respectively. The effect of bull was significant on post-thaw motility, abnormal sperms, noneosinophilic sperms, per cent motility, hypo-osmotic swelling reacted sperms, acrosomal integrity, curvilinear velocity and velocity of ayerage path. The mean conception rate was 44.67%. The multiple linear regression equation based of seminal traits on conception rate showed a high R2 value (90%). The actual,and predicted fertility rate of bulls did not differ significantly. Therefore, fertility rate of breeding bulls could easily be predicted with high accuracy by using the in vitro frozen thawed seminal traits of bulls prior to extensive use through artificial insemination.