Effect of different levels of zinc sulfate of semen extender in Farahani ram breed sperm quality after freezing- thawing

Aim: The purpose of this study was to investigate the effect of adding different levels of zinc (Zn) to semen extender on the sperm parameters after freezing and thawing in rams.
Material and The spermatozoa of five Farahani rams breed (with a mean age of 3 ± 0.5 years and weight of 60 ± 5 kg) were taken twice a week. The semen was collected from the rams by artificial vagina and then the samples were mixed to removing the individualistic effects. The sperm samples (in five replicates) were randomly divided into four groups (zero, 50, 100 and 150 μM of zinc sulfate). Each falcon had the desired diluent that was mixed with Zn and tris and prepared for freezing steps. Samples were stored in semi-milliliter straw and kept with samples under the same conditions and temperatures of 37 °C. Moreover, in these conditions were filled and frozen. Sperm samples were evaluated after thawing for motility, progressive motility, survival (eosin-neogrosin test), sperm membrane integrity (HOST) and sperm morphology (Hancock test).
Results showed no significant difference in the motility percentage and sperm membrane integrity in zinc sulfate environments compared with the control group. The treatment with 50 μm of zinc sulfate showed a higher level of significant (P˂0.05) in the percentage of progressive motility compared with the control group. In sperm viability test, the treatment with 100 μm of zinc sulfate was significantly different from those of 50 and 150 μm zinc sulfate treatment (P˂0.05).
application of zinc sulfate in ram semen extender might be improving some of sperm parameters after the freezing-thawing.