To investigate the effects of dietary n-3 highly unsaturated fatty acids (HUFA) levels on growth, lipid metabolism and innate immunity in juvenile golden pompano Trachinotus ovatus, a marine carnivorous teleost, a total of 450 fish (average body weight: 14.84 g) were randomly distributed into 18 cages at sea, each dietary group with three cages and respectively fed six diets (D1-D6) with 2.30% (D1), 0.64% (D2), 1.00% (D3), 1.24% (D4), 1.73% (D5), or 2.10% (D6) n-3 HUFA. Here, D1 with fish oil as lipid source was set as control, while D2-D6 used a mixed vegetable oil as lipid source and supplemented with docosahexaenoic acid- (DHA) and eicosapentaenoic acid- (EPA) enriched oils to adjust the n-3 HUFA levels. After 8 weeks feeding, the daily growth coefficient (DGC), specific growth rate (SGR) and feed efficiency ratio (FER) showed no significant difference among the six dietary groups (P > 0.05). The levels of EPA and DHA in serum and liver increased with the dietary n-3 HUFA levels. The activity of total superoxide disumutase (T-SOD) in serum of fish fed D4 and D5 were significantly higher than that of the other groups, whereas the opposite was true for serum IL-1β and IL-6 levels as well as liver malondialdehyde (MDA) content. The mRNA levels of genes related to hepatic lipid metabolism including sterol regulatory element-binding protein-1 (srebp-1), fatty acid binding protein 1 (fabp1), peroxisome proliferators-activated receptor alpha (pparα), elongase of very long-chain fatty acids 5 (elovl5) and fatty acyl desaturase 2 (fads2) were down-regulated in fish fed the diets with high n-3 HUFA levels, while those of apolipoprotein b 100 (aprob 100) and carnitine palmitoyl transferase 1 (cpt1) increased significantly as increasing n-3 HUFA levels up to 1.73% (D2-D5), but decreased in the 2.10% n-3 HUFA group (D6). In addition, the expression levels of genes related to innate immunity including interleukin-10 (il-10) and transforming growth factor β1 (tgf-β1) increased significantly when dietary n-3 HUFA increased from 0.64% to 1.73%, whereas the opposite was true for the expression levels of nuclear factor kappa-B (nf-κb), interleukin-1β (il-1β), interleukin-6 (il-6) and interleukin-8 (il-8). Overall, the results indicated that dietary n-3 HUFA at 1.24–1.73% (D4-D5) can effectively improve fatty acid profiles, lipid metabolism, antioxidant capacity and immune response of golden pompano.

研究膳食n-3高不饱和脂肪酸（HUFA）水平对少年金golden鱼Trachnotus ovatus生长，脂质代谢和先天免疫的影响，一种海洋食肉硬骨鱼类，将总共450条鱼（平均体重：14.84 g）随机分配到海上的18个网箱中，每个饮食组三个网箱，分别喂食六种日粮（D1-D6），占2.30％（D1） ，0.64％（D2），1.00％（D3），1.24％（D4），1.73％（D5）或2.10％（D6）n-3 HUFA。在这里，以鱼油为脂质源的D1为对照，而D2-D6使用混合植物油为脂质源，并补充富含二十二碳六烯酸（DHA）和二十碳五烯酸（EPA）的油来调节n-3 HUFA水平。饲喂8周后，六个饮食组之间的日生长系数（DGC），比生长速率（SGR）和饲料效率比（FER）没有显着差异（P > 0.05）。血清和肝脏中EPA和DHA的水平随日粮n-3 HUFA水平的升高而增加。饲喂D4和D5的鱼的血清中的总超氧化物歧化酶（T-SOD）的活性显着高于其他组，而血清IL-1β和IL-6以及肝丙二醛的含量则相反。 MDA）内容。与肝脏脂质代谢相关的基因的mRNA水平，包括固醇调节元件结合蛋白1（srebp-1），脂肪酸结合蛋白1（fabp1），过氧化物酶体增殖物激活受体α（pparα），超长链延长酶脂肪酸5（elovl5）和脂肪酰基脱氢酶2（fads2）在饲喂高n-3 HUFA水平日粮的鱼中被下调，而载脂蛋白b 100（aprob 100）和肉碱棕榈酰转移酶1（cpt1）的鱼显着增加，因为n-3 HUFA水平升高至1.73％（ D2-D5），但在2.10％n-3 HUFA组（D6）中有所下降。另外，当日粮n-3 HUFA从0.64％增加到1.73％时，与先天免疫相关的基因的表达水平，包括白介素10（il-10）和转化生长因子β1（tgf-β1）显着增加，而相反对于核因子κB（nf-κb），白介素-1β（il-1β），白介素-6（il-6）的表达水平是正确的）和白介素8（il-8）。总体而言，结果表明日粮n-3 HUFA含量为1.24–1.73％（D4-D5）可以有效改善金po鱼的脂肪酸谱，脂质代谢，抗氧化能力和免疫反应。