To investigate the response of gibel carp to dietary lysine levels in zero fish meal (FM) diets, 8 experimental diets were designed. Among them, diet 1 and diet 2 with 150 g/kg FM, methionine, lysine and threonine were supplemented in diet 2. Diet 3 was without FM but matched the amino acid profile of diet 2 except for lysine. Diets 4–8 were based on diet 3, with graded levels of lysine. After 8‐week feeding trail, final body weight, weight gain (WG), specific growth rate, feed conversion ratio (FCR) and feed intake were significantly improved by diets 1–2 and 6–8 compared with diet 3. Plasma glucose, triglyceride, immunoglobulin G and aspartate aminotransferase levels in diets 4–8 were higher than those in diet 1. Apparent digestibility coefficients (ADCs) of protein, energy, methionine, lysine, valine, histidine and phenylalanine in diet 1 were significantly lower than those in diet 6. The highest ADC of isoleucine was found in diet 3. TOR, IGF‐1, JAK3, STAT4, STAT6 and PepT2 mRNA levels were significantly increased with increasing dietary lysine up to a certain level in zero FM diet and lower than diets 1–2. Based on WG and FCR, the optimal lysine requirement of juvenile gibel carp was determined to be 24.4 g/kg and 24.2 g/kg (65.9 g/kg and 65.4 g/kg of dietary protein) in zero FM diet, respectively, using quadratic regression analysis.

中文翻译：

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零鱼粉日粮中长鳍鲤对日粮赖氨酸水平升高的响应

为了研究零鱼粉（FM）日粮中长鳍鲤对日粮赖氨酸水平的响应，设计了8种实验日粮。其中，饮食2中补充了饮食1和饮食2，其中饮食中添加了150 g / kg FM，蛋氨酸，赖氨酸和苏氨酸；饮食3中没有FM，但除了赖氨酸外，饮食2的氨基酸特征均与饮食2相符。饮食4-8基于饮食3，赖氨酸水平分级。饲喂8周后，与饮食3相比，饮食1-2和6-8显着改善了最终体重，体重增加（WG），比生长率，饲料转化率（FCR）和采食量。饮食4–8中的甘油三酸酯，免疫球蛋白G和天冬氨酸转氨酶的水平高于饮食1中的蛋白质。表观消化率的蛋白质，能量，蛋氨酸，赖氨酸，缬氨酸，饮食1中的组氨酸和苯丙氨酸显着低于饮食6中的组氨酸和苯丙氨酸。饮食3中发现了最高的异亮氨酸ADC。零FM饮食中有一定水平，低于1-2。根据WG和FCR，使用二次方法确定零日粮中幼龄长鳍金枪鱼的最佳赖氨酸需求量分别为24.4 g / kg和24.2 g / kg（65.9 g / kg和65.4 g / kg的饮食蛋白）。回归分析。