Mahdieh Mehdipour - Department of Animal Sciences, College of Agriculture, University of Tabriz, Tabriz, Iran
Hossien DaghighKia - Department of Animal Sciences, College of Agriculture, University of Tabriz, Tabriz, Iran
Abouzar Najafi - Department of Animal Sciences, College of Agriculture, University of Tabriz, Tabriz, Iran.

Background: High levels of reactive oxygen species (ROS) relating to reduced semen quality, are detected during semen cryopreservation in some species. Although Stachys chtschegleevii was reported to play an important role as in vitro free radical scavengers and could be used as sources of natural antioxidants, there was no study about the cryoprotective effects of Stachys schtschegleevii on ram sperm freezing. The objective of this research was to evaluate the effects of different concentrations of Stachys schtschegleevii added to the freezing extenders on ram sperm motility, viability, abnormal morphology, membrane integrity and lipid peroxidation after thawing.Methods: Semen ejaculates were collected with artificial vagina from four rams, mixed and divided into four equal fractions, and diluted with soybean lecithin extended containing 0 (control), 2, 4 and 6 percent of Stachys chtschegleevii extract. All diluted sperm suspensions were cooled to 4 °C for 2 h followed by loading into 0.25 ml French straws before being stored in liquid nitrogen.Result: After thawing, CASA sperm motility was significantly higher (P < 0.05) in Stachys htschegleevii at 2 and 4 % levels than that in control group. Stachys chtschegleevii at 4 % level led to higher viability, membrane integrity and normal sperm morphology, compared to control groups. In addition, lipid peroxidation in group Stachys chtschegleevii 4 % were lower (P < 0.05) than those of control group.Conclusion: In conclusion, findings of this study showed that Stachys chtschegleevii at 4 % supplementation in semen extenders provided a better protection of sperm parameters against cryopreservation injury.

ROS, Sperm, Stachys chtschegleevii, Cryopreservation