Assessment of Post-1haw Semen Quality of Buffalo and Sahiw Al Bulls Using New Semen Assays

Different semen assays were employed to determine the post -thaw fitness of buffalo and Sahiwal bull spermatozoa. Semen (two ejaculates) was collected from buffalo and Sahiwal bulls (six each) once a week for three consecutive weeks. Semen was diluted in lactose-fructose-egg yolk glycerol extender, equilibrated at 4 ac for 4 hr and frozen in liquid nitrogen vapors. A highly significant difference between fresh and post-thaw motility of both buffalo and Sahiwal bulls was observed (P<O.OOl). Post-thaw percentage of swollen spermatozoa and normal acrosomes were 24 ± 9.4 and 27.3 ± 12.2 in buffalo bulls and 23.4±9.5 and 26.4± 10.4 in Sahiwal bulls, respectively. The respective percentages of buffalo and Sahiwal bull spermatozoa involved in head to head agglutination were 12.1 ±6.7 and 12.4±6.7 at 0 hr and 25. 6 ± 10.8 and 28. 5 ± 7. 2 at 2 hr. Fluorescent microscopy revealed that buffalo and Sahiwal bulls had 22.8±9. 1 and 20. 1 ±8. 3 per cent spermatozoa with intact, 8. 2± 1. 6 and 11.6±4.4 per cent partially damaged, and 68. 8 ±9. 6 and 68.5 ± 10.4 per cent completely damaged plasma membrane. After thawing, there was no significant difference between buffalo and Sahiwal bulls in all semen characteristics. The significant relationships between various semen assays indicate their validity in evaluation of buffalo and