Pure Egyptian Cattle Bulls Show both Individual Variation and Different Interaction with Extender in the Post-Thawing Sperm Parameters

Objectives: As very few studies were done on the freezability of pure Egyptian cattle bull sperm. So, we designed this study to evaluate the individual variations in freezability of native bull semen extended in Tris based diluent and sodium citrate-based diluent. Methods: Semen was collected by artificial vagina, examined at once in farm laboratory. Only semen samples fit the minimum parameters are extended in two extenders first the universal one (TRIS) and second modified Sodium citrate extender by adding glycerol (CU-16) which created at Cornell University to evaluate the individual bull variation and interaction between extender and bull. Results: Post-Thawing individual sperm motility, live, abnormal, acrosome integrity percentage was evaluated in addition to Hypo-Osmotic Swelling test (HOS). The highest value for motility, live abnormal and acrosome percentage were 44.00 ± 1.12, 52.25 ± 1.60, 21.25 ± 0.81 and 62.80 ± 2.58 from bull 2, 1, 3 and 2, respectively for semen extended in TRIS, and 42.25 ± 1.61, 52.00 ± 1.76, 22.15 ± 0.85 and 57.40 ± 3.07, from bull 1, 1, 4, 3, respectively for semen extended in CU-16. The results of HOS were 59.25 ± 1.76 and 55.95 ± 2.13 from bull 1 extended in TRIS and CU-16, respectively. Conclusion: A significant variation (p<0.05) in tested parameter was clear when semen extended in TRIS extender with the absence of such variation when semen extended in CU-16 except in live sperm percentage. With ignoring the extender effect a clear significant variations were detected between bulls in all tested parameters.