Dietary fish oil can change sperm parameters and fatty acid profiles of ram sperm during oil consumption period and after removal of oil source

ABSTRACT

The effects of dietary fish oil on semen quality and sperm fatty acid profiles during consumption of n-3 fatty acids as well as the persistency of fatty acids in ram's sperm after removing dietary oil from the diet were investigated. In this experimental study, we randomly assigned 9 Zandi rams to two groups [isoenergetic and isonitrogenous diets] control [CTR; n=5] and fish oil [FO; n=4] for 70 days with a constant level of vitamin E in both groups. Semen was collected at the first week and at the last week of the feeding period [phase 1]. After the feeding period, all rams were fed a conventional diet and semen samples were collected one and two months after removal of FO [phase 2]. The sperm parameters and fatty acid profiles were measured by computer assisted semen analyzer [CASA] and gas chromatography [GC], respectively. The completely randomized design was used and data were analyzed with SPSS version 16. Dietary FO had significant positive effects on all sperm quality and quantity parameters compared with the CTR during the feeding period [p<0.05]. The positive effects of FO on sperm concentration and total sperm output were observed at one and two months after removal of FO [p<0.05], whereas other sperm parameters were unaffected. Before feeding, C14 [myristic acid], C16 [palmitic acid], C18 [stearic acid], C181 [oleic acid] and C226 [docosahexaenoic acid DHA] were the primary sperm FA. FO in the diet increased sperm DHA, C140 and C180 during the feeding period [p<0.05]. The present study showed not only manipulation of ram sperm fatty acid profiles by dietary FO and sperm parameters during the feeding period, but also the persistency of unique effects of dietary omega-3 fatty acids up to two months following its removal from the diet. Also, we recommend that sperm fatty acid profiles should be comprehensively analyzed and monitored