Authors : S.A. Makawi , B.A. Elsharif and E.A. Babiker
Abstract: The objective of this study was to investigate the freezability of frozen semen collected from two breed-types of Desert sheep (Hamari and kabashi). Nine rams (6 Hamari and 3 kabashi) aged 2-4 years were used in this study to prepare a total of 293 semen ejaculates collected by means of an artificial vagina. The samples were extended in Tris-based diluent, frozen and stored in liquid nitrogen at -196°C. The date obtained revealed that, both breed-types responded equally to the effect of season. Higher percentages of sperm motility were recorded before freezing in autumn (67.07�14.40% vs. 65.42�11.17% for Hamari and Kabashi rams , respectively), while the lowest values were observed in semen samples collected in summer (55.36�7.68% vs. 59.00�5.83). However, no significant difference (p>0.0.5) was found between breeds or seasons on post-thawing sperm motility, although better records were obtained in the Kabashi rams (59.00�5.83%) during Summer, compared to Hamari rams (56.96�6.48%) in the same season. A significant difference (p< 0.05) was observed between the two breed-types and season of the year on the percentage of rejected samples after freezing (15.38 vs 6.35%) with better results obtained in the Kabashi rams. However, post-freezing rejection percentage decreased during autumn and winter (5.56 and 14.29% for Hamari rams with no rejected samples for Kabashi rams). From this study, it could be concluded that, semen collected, throughout the year, from the two breed-types was suitable for freezing. The best semen quality after freezing was obtained during Autumn and Winter.
S.A. Makawi , B.A. Elsharif and E.A. Babiker , 2007. Effect of Season on Freezability of Semen from Two Breed-Types of Desert Sheep in the Sudan . Journal of Animal and Veterinary Advances, 6: 846-849.