Computer assisted sperm analysis: Relationship between the movement characteristics of buffalo spermatozoa and sire fertility

Abstract

The present study was undertaken to identify the differences in sperm kinematics between buffalo bulls with different fertility ratings. Murrah buffalo bulls (n=9) that were routinely used for breeding purpose under progeny testing programme were utilized for the study. Bull fertility was determined based on in vivo fertility trials and the conception rates (CR) were adjusted for different non-genetic parameters. Based on the adjusted CR, bulls were classified into high, medium and low fertile group. Frozen semen samples of these bulls were obtained and sperm kinematic parameters were assessed using a computer assisted sperm analyzer. The kinematic parameters analyzed included the curvilinear velocity (VCL), the linear velocity (VSL), the average path velocity (VAP), the amplitude of lateral head displacement (ALH), the linearity (LIN), the straightness coefficient (STR) and the beat cross frequency (BCF). In high fertile bulls, the proportion of motile spermatozoa was higher (p<0.001) than the medium and low fertile bulls. The VAP and VCL of sperm motion were significantly higher (P<0.05) in high fertile bulls compared to either medium or low fertile bulls. The VSL was significantly lower in low fertile bulls (P<0.005) compared to either high or medium fertile bulls. Spermatozoa from high fertile bulls had significantly higher (P<0.05) BCF, STR, ALH and LIN compared to either medium or low fertile bulls. Buffalo bull fertility was significantly and positively correlated with sperm motility, VAP, VSL, VCL and ALH.