New aspects in freezing cattle Semen

The prpresent work aimed to preserve of bull semen in unfrozen and frozen frozen forms with regard to the unfrozen - semen, two experiments were conduted, in experiment 1,it was intended to establish the best extender with the best levol of prostaglandin f2 during preservation at 37c and refrigeration at 5C. in experiment 2.it was amied to exmine the effects of various concentrations of caffeine on etended semen quality during preservation in liquid state using trisyolk fructose, lactose-yolk citrate and fructose-yolk citrate extenders.and aimed to determin the best level of prostaglandin F2a added frozen-thawed bull semen in different packaging methods. Experiment 6 was carried out to define the best concentration of caffeine added to frozen-thawed bull semen in different packaging methods, and Experiment 7 was carried out to estimate the fertilizing ability of bull semen frozen in forms of straws, pellets, and tablets.