Wang Liping, Han Yuzhe, Jiang Zhiqiang, Sun Menglei, Si Bin, Chen Fei, Bao Ning
Key Laboratory of Mariculture and Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, 52 Heishijiao Street, Dalian, 116023, China.
Fish Physiol Biochem. 2017 Oct;43(5):1265-1278. doi: 10.1007/s10695-017-0370-3. Epub 2017 Apr 12.
A 60-day feeding trial was conducted to assess the interactions of dietary leucine (Leu) and isoleucine (Ile) on Japanese flounder. Fish of 2.69 ± 0.04 g were fed experimental diets containing two levels of Leu (2.58 and 5.08% of diet) combined with three levels of Ile (1.44, 2.21, and 4.44% of diet), respectively. After the feeding trial, growth, proximate composition, muscle total amino acid profile, blood parameters, mucus lysozyme activity, and stress tolerance to freshwater were measured. Statistically significant (P < 0.05) interactive effects of Leu and Ile were found on growth parameters (final body weight, body weight gain, and special growth rate) of Japanese flounder. Antagonism was discovered in high dietary Leu groups, while stimulatory effects were obtained for increased dietary Ile in low Leu groups. Interactive effects of these two branched-chain amino acids were also found on hepatosomatic index of test fish. In addition, crude lipid content of fish whole body was significantly altered by various diets, with antagonism observed in low dietary Leu groups. Interactive effects also existed in muscle amino acid profiles for low fish meal diets, but no interactive impacts were observed on blood parameters. Furthermore, lysozyme activities and freshwater stress were significantly affected by different diets. And antagonism was found on lysozyme activities in low Leu groups. Moreover, high Leu and high Ile levels of diet significantly altered freshwater stress tolerance of Japanese flounder. These findings suggested that dietary Leu and Ile can effect interactively, and fish fed with diets containing 2.58% Leu with 4.44% Ile and 5.08% Leu with 1.44% Ile showed better growth performance.
进行了一项为期60天的饲养试验，以评估日粮中亮氨酸（Leu）和异亮氨酸（Ile）对牙鲆的交互作用。将体重为2.69±0.04克的鱼投喂含两种亮氨酸水平（分别占日粮的2.58%和5.08%）与三种异亮氨酸水平（分别占日粮的1.44%、2.21%和4.44%）组合的试验日粮。饲养试验结束后，测定生长、常规成分、肌肉总氨基酸谱、血液参数、黏液溶菌酶活性以及对淡水的应激耐受性。发现亮氨酸和异亮氨酸对牙鲆的生长参数（终末体重、体重增加和特定生长率）具有统计学显著（P<0.05）的交互作用。在高日粮亮氨酸组中发现拮抗作用，而在低亮氨酸组中增加日粮异亮氨酸则有刺激作用。还发现这两种支链氨基酸对试验鱼的肝体指数有交互作用。此外，不同日粮显著改变了鱼体的粗脂肪含量，在低日粮亮氨酸组中观察到拮抗作用。低鱼粉日粮的肌肉氨基酸谱中也存在交互作用，但对血液参数未观察到交互影响。此外，不同日粮显著影响溶菌酶活性和淡水应激。在低亮氨酸组中发现溶菌酶活性存在拮抗作用。而且，高亮氨酸和高异亮氨酸水平的日粮显著改变了牙鲆对淡水的应激耐受性。这些结果表明，日粮中的亮氨酸和异亮氨酸可产生交互作用，投喂含2.58%亮氨酸与4.44%异亮氨酸以及5.08%亮氨酸与1.44%异亮氨酸日粮的鱼生长性能更佳。
