Comparative Evaluation of Motility and Kinematics of Fresh Versus Frozen-Thawed Spermatozoa of Cattle and Buffalo Bull by CASA

Abstract

A study was undertaken on semen of three mature bulls each of Gir, Surti and Murrah breed to evaluate the comparative motion characteristics and kinematics of their fresh and frozen-thawed spermatozoa by Biovis CASA. The ejaculates (n= 24/breed) having >75% initial motility were diluted @ 80 million sperm/ml using TFYG extender and were assessed. Amongst motility traits, the total motile, rapid progressive motile and slow progressive motile spermatozoa percentage decreased significantly by 23.08 - 30.09, 43.57 - 55.18, 9.12 - 22.75 %, respectively, plessthan0.01), while non-progressive motile sperm (4.78 - 21.48%) and immotile sperm (164.38 - 178.38 %) percentage increased significantly ( plessthan0.01) in frozen-thawed semen compared to that of fresh semen. The post-thaw quality of semen of all three breeds was in acceptable range. The mean values of sperm velocity/kinematic parameters observed in frozen-thawed semen of Gir, Surti and Murrah bulls, based on total motile sperms, viz., average path velocity, curvilinear velocity, straight line velocity, linearity, straightness, beat-cross frequency, amplitude of lateral head displacement, dancing frequency and dancing mean decreased significantly by 13.70 - 17.79; 9.76 - 12.95; 13.28 - 21.90; 7.28 - 9.68; 4.36 - 7.79; 15.56 - 25.15; 8.78 - 10.50; 6.16 - 18.67 and 12.98 - 15.96 %, respectively, as compared to that of their fresh semen samples. However, wobbling index remained almost same for both fresh and frozen semen. All motility traits differed but none of kinematics/velocity traits differed significantly between breeds/species. The values of all velocity parameters for progressive motile sperms were higher than total motile sperms in all three breeds. The effect of freezing-thawing on velocity and kinematic attributes was much less compared to absolute sperm motility, and both the fresh and frozen-thawed sperms behaved identically with respect to their velocity and kinematics. The rapid progressive motile sperm in both fresh (r=0.41 to 0.92) and frozen-thawed (r=044 to 0.88) semen had significant correlations with most of their velocity traits, and the later were significantly and positively or negatively inter-related among each other in semen of all three breeds. It was therefore concluded that cryopreservation process significantly reduces the motility and kinematics attributes of bovine spermatozoa and, CASA analysis of fresh semen for motility and velocity traits could predict the post-thawed sperm motility and velocity/ kinematics of spermatozoa.