Abstract A 60-day feeding trial was conducted on Genetically Improved Farmed Tilapia (GIFT) juveniles in inland saline water (ISW) of 10 ppt salinity. Seven isoenergetic (400 kcal DE/100 g), isolipidic (6%) and hetero‑nitrogenous (20, 25, 30, 35, 40, 45 and 50% CP) experimental diets were formulated and prepared using purified ingredients. Three hundred and fifteen GIFT juveniles (average body weight 2.68 ± 0.01 g) were distributed in seven experimental groups viz., T20 (20% CP), T25 (25% CP), T30 (30% CP), T35 (35% CP), T40 (40% CP), T45 (45% CP) and T50 (50% CP) in triplicates following a completely randomized design (CRD) with the stocking density of 15 fish/tank (92 cm diameter X 45 cm height) with 200 l water volume. Fishes of different experimental groups were fed with respective experimental diets thrice daily at satiation level. Results indicated that dietary crude protein has significant (p I) and Insulin like growth factor I receptor (IGF IR) were highly correlated with WG% (r = 0.92 and r = 0.97, respectively). The expression of IGF IR was also correlated with IGF-I expression (r = 0.93). According to broken-line and second-order polynomial regression analysis in relation to WG% and expression of hepatic IGF-I gene, the optimum dietary crude protein levels of GIFT juveniles reared in inland saline water of 10 ppt salinity were found to be 37.37, 37.72, 40.92 and 38% crude protein with isoenergetic of 400 kcal DE/100 g diet, respectively.

中文翻译：

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给内陆咸水中饲养的遗传改良养殖罗非鱼 (GIFT) 幼鱼饲喂分级水平的蛋白质：对 IGF I、IGF-IR 和 IGF-BPI 生长和基因表达的影响

摘要 在盐度为 10 ppt 的内陆咸水 (ISW) 中，对转基因养殖罗非鱼 (GIFT) 幼鱼进行了 60 天的饲养试验。使用纯化成分配制和制备七种等能（400 kcal DE/100 g）、异脂（6%）和异氮（20、25、30、35、40、45和50% CP）实验饮食。315 只 GIFT 幼鱼（平均体重 2.68 ± 0.01 g）分布在七个实验组中，即 T20（20% CP）、T25（25% CP）、T30（30% CP）、T35（35% CP） )、T40 (40% CP)、T45 (45% CP) 和 T50 (50% CP) 按照完全随机设计 (CRD) 一式三份，放养密度为 15 条鱼/鱼缸（直径 92 厘米 X 45 厘米高） 200 升水量。不同实验组的鱼在饱食水平下每天喂三次各自的实验饮食。结果表明，日粮粗蛋白具有显着性（p I）且胰岛素样生长因子 I 受体（IGF IR）与 WG% 高度相关（分别为 r = 0.92 和 r = 0.97）。IGF IR 的表达也与 IGF-I 表达相关（r = 0.93）。根据WG%和肝脏IGF-I基因表达的折线和二阶多项式回归分析，发现10 ppt盐度内陆咸水中饲养的GIFT幼鱼的最佳日粮粗蛋白水平为37.37，分别为 37.72、40.92 和 38% 的粗蛋白，等能能量为 400 kcal DE/100 g 饮食。IGF IR 的表达也与 IGF-I 表达相关（r = 0.93）。根据WG%和肝脏IGF-I基因表达的折线和二阶多项式回归分析，发现10 ppt盐度内陆咸水中饲养的GIFT幼鱼的最佳日粮粗蛋白水平为37.37，分别为 37.72、40.92 和 38% 的粗蛋白，等能能量为 400 kcal DE/100 g 饮食。IGF IR 的表达也与 IGF-I 表达相关（r = 0.93）。根据WG%和肝脏IGF-I基因表达的折线和二阶多项式回归分析，发现10 ppt盐度内陆咸水中饲养的GIFT幼鱼的最佳日粮粗蛋白水平为37.37，分别为 37.72、40.92 和 38% 的粗蛋白，等能能量为 400 kcal DE/100 g 饮食。