The effect of different levels of glycerol in tris and citrate extenders on characteristics of Zel rams frozen semen

The objective of present study was to investigate the effect of different levels of glycerol in tris and citrate extenders on Zel rams semen characteristics in frozen condition. Semen samples were collected from 4 Zel rams using artificial vagina and suitable samples were mixed together and subjected to different treatments in tris and citrate extenders. Spermatozoa characteristics including percentage of motile and viable cells were assessed. The experiment was carried out on the basis of completely randomized design with 5 treatments and 3 replicates. Treatments were different levels of glycerol (0, 1, 3, 5 and 7 percentage). Results showed that, the effect of glycerol on motility and viability percentage of spermatozoa in tris and citrate extenders were significant in frozen condition (P<0.05). Means comparison of treatments on the basis of Duncan test showed that the highest motility (%41.4±2.3) and viability (%45.9±1.9) of spermatozoa in tris and highest motility (%39.2±2.7) and viability (%43±2.3) of spermatozoa in citrate extenders were obtained in 5 percent of glycerol. In conclusion, using 5 percent of glycerol in tris and citrate extenders is recommended for storage of Zel ram semen in frozen condition.