Influence of dietary n-3 LC-PUFA on growth,nutritional composition and immune function in marine fish Sebastiscus marmoratus

A 60-day feeding experiment was conducted to investigate the influence of dietary omega-3 long-chain polyunsaturated fatty acids(n-3 LC-PUFA) on growth, nutritional composition and immune function of marine fish Sebastiscus marmoratus. Five diets containing 3.6, 10.2, 18.2, 26.5, or 37.0 g/kg n-3 LC-PUFA were prepared. The results reveal significant influences of dietary n-3 LC-PUFA on the final weight, weight gain, specific growth rate, feed conversion ratio, and condition factor. As dietary n-3 LCPUFA increased, weight gain and specific growth rate increased and were significantly higher in groups fed 18.2, 26.5 and 37.0 g/kg than in groups fed 3.6 and 10.2 g/kg( P 0.05); there was no significant difference between groups fed 18.2, 26.5, or 37.0 g/kg( P 0.05). With increasing dietary n-3 LC-PUFA, eicosapentaenoic acid and docosahexenoic acid content in muscle and liver increased significantly, immunoglobulin class M content gradually increased from 9.1 to 14.8 μg/L, and lysozyme activity content increased from 1355 to 2268 U/mL. Broken line model analysis according to weight gain indicated that a dietary n-3 LC-PUFA level of 18.2 g/kg is essential for normal growth at a fat level of 125 g/kg. Therefore, appropriate dietary n-3 LC-PUFA not only promote growth and improve the n-3 LC-PUFA content, but also enhance immune function in S. marmoratus.     

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庄子在其名作《逍遥游》的开篇写道：＂北冥有鱼,其名为鲲。鲲之大,不知其几千里也;化而为鸟,其名为鹏。＂据某些学者考证,这篇文章里所写的鲲,实际上就是鲸,而鹏,其实就是信天翁。你还在为体重增加而烦恼吗？你还在为减肥而发愁吗？信天翁的遭遇告诉我们：体重增加,那都是全球气候变暖惹的祸!