Effects of different dietary ratios of docosahexaenoic to eicosapentaenoic acid (DHA/EPA) on the growth, non-specific immune indices, tissue fatty acid compositions and expression of genes related to LC-PUFA biosynthesis in juvenile golden pompano Trachin
Effects of different dietary ratios of docosahexaenoic to eicosapentaenoic acid (DHA/EPA) on the growth, non-specific immune indices, tissue fatty acid compositions and expression of genes related to LC-PUFA biosynthesis in juvenile golden pompano Trachin
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不同二十二碳六烯酸与二十碳五烯酸（DHA/EPA）配比对金鲳鲳幼鱼生长、非特异性免疫指标、组织脂肪酸组成及LC-PUFA生物合成相关基因表达的影响
DOI：
10.1016/j.aquaculture.2019.01.061
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发表时间：
2019
期刊：
影响因子：
4.5
通讯作者：
Li Yuanyou
中科院分区：
文献类型：
--
作者：
Zhang Mei;Chen Cuiying;You Cuihong;Chen Baojia;Wang Shuqi;Li Yuanyou
n-3长链多不饱和脂肪酸（n-3LC-PUFA）如二十二碳六烯酸（DHA）和二十碳五烯酸（EPA）是海洋肉食性鱼类必需的脂肪酸。因此，确定最佳膳食DHA/EPA比例对于开发更好的饲料配方至关重要。在本研究中，一种海洋肉食性鱼类，金鲳（卵形鲳鲹）的青少年进行了6个等蛋白和等脂肪的饮食含有不同比例的DHA/EPA（0.53，0.81，1.17，1.48，1.69，和2.12）和恒定水平的n-3 LC-PUFA（干重的1.20%）。在10周的饲养试验后，饲喂DHA/EPA比为1.17和1.48的饲料的鱼获得了最佳的生长性能，与饲喂其他饲料的鱼相比，具有显著更高的增重（WG）和特定生长率（SGR）（P <0.05）。DHA/EPA比为1.48时，血清中溶菌酶（LZM）、过氧化氢酶（CAT）和超氧化物歧化酶（SOD）活性显著高于其它各组（P <.05）。T.日粮对鸡的卵、肌、肝、眼和脑有显著影响。肌肉、眼和脑组织中DHA和DHA/EPA的含量均随饲料中DHA/EPA比例的增加而显著增加，且脑组织中DHA的含量远高于其它组织。随着日粮DHA/EPA比例的增加，肝脏中elov15-like和Δ 6 fad的表达量以及大脑中elov14-like和Δ 6 fad的表达量均显著增加（P <0.05）。二次多项式回归分析表明，幼鱼在DHA/EPA比为1.40时生长最快。在本研究中，推荐的最佳DHA/EPA比例为卵形。
The n-3 long chain polyunsaturated fatty acid (n-3 LC-PUFA) such as docosahexaenoic and eicosapentaenoic acids (DHA and EPA) are essential fatty acids for marine carnivorous fish. Thus, the determination of optimal dietary DHA/EPA ratio is essential for the development of better feed formulation. In the present study, a marine carnivorous fish species, golden pompano (Trachinotus ovatus) juveniles were subjected to six isoproteic and isolipidic diets contained differential ratios of DHA/EPA (0.53, 0.81, 1.17, 1.48, 1.69, and 2.12) and a constant level of n-3 LC-PUFA (1.20% of the dry weight). After the 10-week feeding trial, fish fed the diet with DHA/EPA ratios of 1.17 and 1.48 achieved the best growth performance, with significantly higher weight gain (WG) and specific growth rate (SGR) than that fish fed the other diets (P< .05). At the DHA/EPA ratio of 1.48 group, non-specific immune indices, including the activities of lysozyme (LZM), catalase (CAT) and superoxide dismutase (SOD) in serum were significantly higher than those of other groups (P< .05). Fatty acid compositions ofT. ovatusmuscle, liver, eye and brain were significantly affected by the diets. The content of DHA and DHA/EPA in muscle, eye and brain both markedly increased with increasing dietary DHA/EPA ratios, and the concentration of DHA in brain was much higher than other tissues. Both the expression ofelovl5-likeandΔ6 fadin liver and the expression ofelovl4-likeandΔ6 fadin brain significantly increased with increasing dietary DHA/EPA ratios (P< .05). When subjecting the WG to the second-order polynomial regression analysis, the maximal growth was achieved at 1.40 of DHA/EPA ratio for the juvenileT. ovatus, which was thought as the recommended optimum requirement of dietary DHA/EPA ratio in the current study.