中文摘要：

选用初始体重为（50．14±3．33）g的草鱼80尾，饲养于四个循环水养殖缸4W，饲养期水温18—22℃。分别饲喂以三油酸甘油酯制品（对照组）、三油酸甘油酯制品和精制鱼油混合油（HUFA组）为脂肪源的两种试验饲料。饲养结束后对试验鱼不同组织脂肪酸组成、生物学性状、体组成、血清生化指标、脂质代谢酶活性、脂蛋白脂酶（LPL）基因表达及肝胰脏抗氧化指标进行测定。脂肪酸分析表明，饲料中HUFA显著影响鱼体组成：HUFA组草鱼腹腔脂肪组织中C22：6n-3（P〈0．01）、HUFA（P〈0．05）含量显著升高；肌肉组织中n-3（P〈0．01）、HUFA（P〈0．05）含量显著升高，而C20：4n-6含量显著降低（P〈0．05）；肝胰脏和脑组织中HUFA含量没有显著差异（P〉0．05），除脑组织外，肝胰脏、肌肉、腹腔脂肪组织中n-3／n-6均显著升高（P〈0．05）。与对照组相比，HUFA组腹腔脂肪指数、肝胰脏脂质含量显著降低，肝胰脏T—AOC活性显著升高（P〈0．05），肝胰脏LPL活性及基因表达丰度均显著降低（P〈0．05）。研究指出，饲料中HUFA显著影响了草鱼组织脂肪酸组成，且这种影响具有组织特异性。饲料HUFA具有抑制草鱼脂质合成及向肝组织的脂质转运、降低肝胰脏脂质及腹腔脂肪的沉积、提高草鱼抗氧化能力的作用。

英文摘要：

The study was conducted to examine the effect of dietary fatty acid composition on body composition and lipid metabolism of grass carp. Two semi-purified experimental diets were formulated containing either triolein （Control diet） or a fish oil concentrate rich in n-3 highly unsaturated fatty acid mixture （HUFA diet） as the main lipid source, and fed to duplicate groups （20 fish/tank） of grass carp （initial weight = 50 ±3 g/fish） for 4 weeks at 18-22℃. Fatty acid and proximate composition of different organs or body compartments, morphological characteristics, serum biochemical indicators, the activity of key enzymes of lipid metabolism, LPL mRNA expression, and hepatopancreas anti-oxidant systems were determined at the end of the 4-week feeding trial. Dietary HUFA were incorporated into the fish body effectively. Analysis of fatty acid indicated that a higher content of C22：6n-3 〈 P 〈 0.01 ） and HUFA （P 〈 0. 05） were found in intraperiotenal fat （IPF） , and a higher content of n-3 （P 〈 0.01 ） and HUFA （P 〈 0.05） but lower C20 ：tin-6 content （P 〈 0. 05） in muscle of HUFA group. There was no significant difference in fatty acid composition of both the hepatopancreas and brain of fish fed the two diets. The content of n-3/n-6 was significantly higher in the hepatopancreas, IPF, and muscle in fish fed the HUFA diet compared to the control diet. The content of IPF and hepatopancreas lipid （P 〈 O. 05） was lower in the HUFA group. On the other hand, a significantly higher T-AOC activity, the lower LPL activity and LPL mRNA expression （P 〈 0. 05） was observed in the hepatopancreas of fish fed the HUFA diet. It could be concluded that the fatty acid composition of the experimental fish was affected by fatty acid composition of the diet. However, the fatty acid composition of different body compartments of grass carp differed significantly. Dietary HUFA might inhibit the activity of lipogenesis enzymes or decrease lipid storage leading to lower hepatopan