Dietary effects of eicosapentaenoic acid and docosahexaenoic acid on growth, lipid accumulation and antioxidation system in juvenile grass carp, Ctenopharyngodon idellus | 饲料DHA/EPA比率对草鱼稚鱼生长、脂质蓄积及抗氧化系统的影响

chinois. 评估饲料DHA/EPA比率对草鱼稚鱼生长、脂质蓄积及抗氧化状态的影响，为完善草鱼高不饱和脂肪酸营养理论及合理进行饲料脂质的配比提供参考。将198尾草鱼稚鱼(平均体质量（17.6±1.2） g)以11尾/缸的密度随机投放于18个循环水养殖缸中，随机分为6组，进行为期38 d的饲养试验，对照组草鱼稚鱼饲喂仅可满足必需脂肪酸需求的饲料，试验组草鱼饲喂在满足必需脂肪酸需求的基础上，添加0.5%HUFA、DHA/EPA比率分别为4.93(试验Ⅰ组)，2.05(试验Ⅱ组)，1.08(试验Ⅲ组)，0.49(试验Ⅳ组)，0.21(试验Ⅴ组)的饲料。饲养试验结束后，测量试验鱼体长和体质量，采取全鱼、肌肉、肝胰脏等进行相关指标的测定和分析。试验Ⅴ组草鱼稚鱼终末体质量、相对生长率和特定生长率显著高于对照组；试验Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ组的饲料效率和蛋白质效率均显著高于对照组，各试验组之间无显著差异；试验Ⅱ和Ⅲ组肌肉粗脂肪含量显著高于对照组，试验Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ组肝胰脏粗脂肪含量无显著差异，但均显著低于对照组；对照组肝胰脏T-Aoc显著高于试验Ⅰ、Ⅱ、Ⅲ和Ⅳ组，其余各试验组差异不显著；各处理组间肝胰脏CAT、SOD活性和MDA含量差异均不显著。添加HUFA具有促进草鱼稚鱼生长和调控体脂在组织间分配的作用，并表现出诱发氧化应激的趋势，而饲料DHA/EPA比率在4.93~0.21对草鱼稚鱼的生长、脂质蓄积和抗氧化状态没有显著性影响。

anglais. Effects of eicosapentaenoic acid and docosahexaenoic acid on growth performance, lipid accumulation and antioxidant status in juvenile grass carp (Ctenopharyngodon idellus) were studied. A total of 198 grass carp juveniles (body weight (17.6±1.2) g)were randomly assigned into six groups with triplicate, totally 18 tanks with 11 fish each. Grass carp juveniles were reared in glass-steel tanks (200 L volume per tank) with a continuous flow of water and aeration, temperature 28C30 ℃,dissolved O2 6C8 mg/L and pH 7.5C7.7. Grass carp juveniles were fed for 38 days six experimental diets (CK and Ⅰ to Ⅴ) with the same amount of DHA and EPA (0.5% of dried diet), but varying ratios of DHA to EPA (4.93, 2.05, 1.08, 0.49 and 0.21 respectively) and a control diet (CK, no DHA and EPA included). Final weight, weight gain and specific growth rate in treatment Ⅴ were significantly higher in control group (P0.05). The feed efficiency and protein efficiency were significantly higher in treatment Ⅰ,Ⅱ,Ⅲ, Ⅳ and Ⅴ(P0.05), however, there were no statistically significant differences among treatment Ⅰ to Ⅴ. Muscle lipid content in treatment Ⅱ and Ⅲ significant higher (P0.05). Hepatopancreas lipid content in treatmentⅠ to Ⅴ was significantly lower than that of control group (P0.05), however, there were no statistically significant differences in hepatopancreas lipid content among treatmentⅠ to Ⅴ. The activities of total anti-oxidative capacity (T-Aoc) showed no statistically significant differences among groups. The activities of catalase (CAT), superoxide dismutase (SOD) and the content of malondialdehyde (MDA) kept constant in all groups (P0.05). The activities of total antioxidative capacity (T-Aoc) in control group were significantly higher than that of treatmentⅠ to Ⅳ(P0.05). It was concluded that HUFA could promote growth performance and adjust the distribution of body fat among tissues, also might induce oxidative stress, but the growth performance, lipid-accumulation and antioxidation system were not influenced by DHA/EPA (4.93C0.21).