Effect of conjugated linoleic acid isomer -cis-9, trans-11- on the cytological parameters of post-thaw ram spermatozoa

Document Type : Original Article

Authors

1 Department of Theriogenology Faculty of Veterinary Medicine, Cairo University; Giza, Egypt

2 Department of Theriogenology, Faculty of Veterinary Medicine, Cairo University; Giza, Egypt

Abstract

The present study aimed to evaluate the effect of addition of conjugated linoleic acid isomer-cis-9,trans-11- (CLA) to egg yolk-Tris glycerol diluent on the cytological parameters of post-thaw ram spermatozoa. Different concentrations of CLA (50, 100 and 150 μM) were added to the cryopreservation medium of ram semen. Five fat-tailed rams were used and their ejaculates were pooled and processed. Conjugated linoleic acid, which had oily presentation, were prepared by dissolving it in ethanol. Treated diluted semen was cooled, equilibrated and subjected to cryopreservation. The motility characteristics of the post-thaw spermatozoa were analyzed objectively; plasma membrane integrity by hypo osmotic swelling test (HOST), alive and abnormal sperm percentage by eosin negrosin stain and hanocock’s method and acrosomal integrity by spermac stain. Results showed that CLA (100 and 150 μM) increased significantly (P< 0.05) the live sperm percentage, HOST and intact acrosome percentage of frozen thawed ram semen compared to control. Regarding the effect of CLA on the total sperm abnormalities, the 150 pM CLA was the only concentration that decreased significantly (P <0.05) the percentage of abnormal sperm cell compared to control (15.0 vs 19.4%). However, concentrations (50, 100 and 150 1M) tested decreased significantly (P <0.05) the percentage of abnormal sperm (21.6%, 17% and 15%, respectively compared to control with ethanol 29.2%). The effect of different concentrations (50, 100 and 150 μM) of CLA on the progressive motility percentage was non significant. It could be concluded that, CLA improved the freezability of ram spermatozoa in terms of membrane and acrosome integrity and decreased sperm cell abnormalities.

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