Effect of adding catalase and glutathione reduce to Tris extender on freezing ability of Holstein bulls following different cryopreservation periods

Abstract

This study was conducted to explore the adding effect of enzymatic antioxidants Catalase, and glutathione reduced and their combinations to Tris extender on freezing ability of Holstein bulls for different periods. Seven Holstein bulls of 2.5-3 years old were used in this study. Semen was collected via artificial vagina at once ejaculate/ bull/ week. The fresh semen was pooled and then equally divided for various treatments within each experiment using Tris extender. The first experiment was considered as control group. In the second experiment, catalase was added and in the third experiment, glutathione reduced were added separately with the concentrations of 100 IU and 0.2 mM/ml, respectively and as binary combinations of them using similar singular concentrations in fourth experiment. The effect of these adding on freezing ability of Holstein bulls on different cryopreservation periods after 48 Hrs., 1, 2 and 3 months were studied. The results showed that in the second experiment where Catalase added exhibited highly (P<0.01) freezing ability percentage and during all preservation periods in compared with control group. In third experiment, addition of glutathione reduced to Tris extender has improved (P<0.01) in freezing ability during the whole preservation periods in comparison with control group. Considerable increasing (P<0.01) in freezing ability percentage was observed in fourth experiment following addition the combinations of Catalase, and glutathione reduced to Tris extender during all cryopreservation periods in comparison with control group. In conclusion of this study, the addition of some enzymatic antioxidants Catalase and glutathione reduced and their combinations led to improved freezing ability of Holstein bulls during different cryopreservation periods, or may lead to increase the fertility rate among the cows and then increase the economic return for owners