effect of antioxidant combinations on sperm quality of cross breed rams during liquid storage

the aim of this study was to evaluate the effects of the addition of antioxidants (vitamin e, β- mercaptoethanol and their combination) to semen extender.  progressive motility, viability and ph of fresh ram semen were examined. ejaculate samples were collected with artificial vagina from three ghezel-merinose rams (3 years old) during non- breeding reproduction season. semen was diluted with a citrate-base extender containing group1,without antioxidants,  group2,vitamin e 5mm,  group3, β- mercaptoethanol (β-me) 50mm  and group4,  vitamin e(5mm) &amp;m β-mercaptoethanol 50m. diluted semen was cooled to 5º c and storage at same temperature for 72h. semen was investigated after 24, 48 and 72h. result showed that progressive motility and viability in control group were higher than other treatment groups. the progressive motility in vitamin e supplemented group was significantly higher than other groups supplemented with antioxidant. the addition of vitamin e to the extender increased (p< 0.05) sperm viability compared to other groups supplemented with antioxidants.  progressive motility and viability were significantly higher than other (p< 0.05) in the vitamin e group. viability and progressive motility were significantly higher in vitamin e &amp; β-me groups than in β-me. in conclusion vitamin e supplementation of citrate –egg yolk extender improved progressive motility and viability fresh sperm during storage at 5º c for 72h.  sperm storage time had a significant effect on sperm viability and progressive motility.  based on this study, there were no combinations more efficient at combating semen quality than control group