Effects of DHA supplementation of the extender containing egg yolk and α- tocopherol on the freezability and post-thawing fertility of ram semen

• Published in: Small ruminant research 2015-09, Vol.130, p.166-170
• Main Authors: Abdi-Benemar, H., Jafaroghli, M., Khalili, B., Zamiri, M.J., Ezazi, H., Shadparvar, A.A.
• Format: Article
• Language: English
• Subjects: Cryopreservation; DHA; Ram; Semen
• ISSN: 0921-4488; 1879-0941
• DOI: 10.1016/j.smallrumres.2015.06.013

•Effects of DHA supplementation of ram semen extenders were evaluated.•We have investigated freezability and post-thawing fertility of ram semen.•DHA supplementation of ram semen extenders improved post-thawed semen characteristics.•Insemination of the DHA enriched extenders resulted in higher fertility rate in ewes after thawing. The aim of present study was to evaluate the effect of increasing the DHA content of a basic Tris, extender supplemented with different level of fish oil on post-thawing ram semen quality and fertility. The semen samples were collected from four fertile rams, pooled and diluted (1:4) with a Tris–citric acid–fructose–yolk extender, supplemented with different concentrations (0.15, 0.30 or 0.45g) of fish oil per gram egg yolk. In control group, semen was diluted in the basic diluent, without fish oil. After aspiration into 0.25mL straws, the semen samples were cooled to 5°C within 90min and frozen by exposure to liquid nitrogen vapor. After 24h, straws were thawed in a water bath (37°C) for 30s. All characteristics of frozen-thawed sperms were improved by increasing the level of the fish oil till 0.30g fish oil (P