Ram infertility can be the result of different changes made in their reproductive health. The objective of this study was to assess the effect of zinc sulfate treatment on motility characteristics in Farahani rams sperm at in vitro after freezing-thawing. Problems with the production, maturity, motion and fertility of sperms are among the major causes of ram infertility according to the reports. Zinc antioxidant contributes to inhibition of the destructive effects of free radicals in sperms after cryopreservation. The aim of this study was to analyze the role of zinc in the improvement motility characteristics. Semen was collected from four adult rams twice a week and samples pooled together. Sperm samples (five repeats) containing zinc sulfate in three levels (0, 50, 100 µMol) had been frozen. After semen samples freezing, samples were thawed and examined in terms of motility. Average total motility at 100µMol zinc sulfate were lower than other treatments (P<0.05). A significant reduction was observed in the motility rate with increasing zinc sulfate concentration (P<0.05). The results did not show significant effect of Zn supplementation on sperm motility. It can be concluded that Zn supplementation had no effect on sperm motility.
