RESUMO
Effect of vitamins E and C on bull's sperm during refrigeration was studied. Semen was collected from a healthy bull and diluted with an extender to 20 x 10[6]/ ml. The extended semen was divided into 3 equal parts and each one received either vitamin E [T[1] = 40 micro g/ml], vitamin C [t[2] = 200 micro g/ml] or neither one [T[3] = 0]. eight samples [ependorf = 1 ml] from each treatment were made and placed in refrigerator [5 C] for four days. The treatments were evaluated during 4 days according to: E[1], C[1]=24, E[2], C[1] = 48, E[3], C[3] = 72 and E[4], C[4] = 96 hours. Every day 2 samples from each treatment were selected randomly and evaluated for PH, %SNM, FSC, SMI, MSC, %PSM and TSC. The control treatment was measured in the first day and the C[4] treatment due to death of sperms was not evaluated. The level of pH for E[1] treatment significantly increased when compared to control group. Number of nomal sperm in treatments E[1]. E[2] and C[1] were increased when compared to control group [p< 0.01]. Also, treatment E[1], E[2] and C[1] were showed significantly increase for FSC when compared to control group where as E[4], C[2] and C[3] were reduced [p< 0.01]. The percent SMI in E[1], E[2] and C[1] treatments was increased significantly in comparsion to control group while E3 and C[2] treatments didn't differ but E[4] and C[3] treatments were shon reduction [p< 0.01]. The amount of MSC in E[1], E[2] and C[1] treatments were increased significantly when compared to control group but E[3], E[4] and C[2] treatments didn't differ; however the C[3] showed significantly decrease [p< 0.01]. The percent PSM in E[1], E[2] and C[1] treatment were increased in comparsion to control group [p< 0.01], where as the E[3], E[4] and C[2] had no differences but the C[3] showed significantly decrease. The sperm concentration in E[1], E[2] and C[1] treatments were increased significantly in comparsion to control group but the E[3], E[4] and C[2] treatments did not differ. The resultes of this study showed that adding vitamin E [40 micro g/ml] or vitamin C [200 micro g/ml] to semen may prevent sperm membrane destruction at least for 48 or 24 hours during refrigeration receptively, thus the quality of sperm will improve