This study aimed at determine the digestible lysine requirement of tambaqui juveniles using the diet dilution technique. A total of 250 juveniles tambaqui with an initial mean of 22.99 ± 1.06 g were used in a dose-response experiment with five levels of digestible lysine (0.865, 1.125, 1.383, 1.644 and 1.903%) and five replication per treatment. The digestible lysine levels evaluated did not influence the feed intake ( > 0.05), but there was a linear effect ( < 0.05) on the digestible lysine intake. Quadratic effects on weight gain, specific growth rate, feed conversion ratio, and body protein deposition were observed, estimating the requirements at 1.39; 1.37; 1.37 and 1.58% digestible lysine, respectively. Since there was no effect on the feed intake and, consequently, on energy consumption, the improvements in feed conversion ratio and weight gain occurred owing to the better amino acid balance of the rations in the requirement of digestible lysine. The requirement for digestible lysine in the diet for tambaqui juveniles was determined at 1.58% by the body protein deposition, which corresponds to 5.76% dietary crude protein.

中文翻译：

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使用饮食稀释技术测定 Tambaqui (Colossoma macropumum) 幼鱼的可消化赖氨酸需求


本研究旨在利用饮食稀释技术确定 tambaqui 幼鱼的可消化赖氨酸需求量。总共 250 只初始平均体重为 22.99 ± 1.06 g 的幼鱼被用于剂量反应实验，其中可消化赖氨酸有五个水平（0.865、1.125、1.383、1.644 和 1.903%），每次处理重复 5 次。评估的可消化赖氨酸水平不影响采食量（> 0.05），但对可消化赖氨酸摄入量存在线性影响（< 0.05）。观察到增重、特定生长率、饲料转化率和体内蛋白质沉积的二次效应，估计需求量为 1.39； 1.37；可消化赖氨酸分别为 1.37% 和 1.58%。由于对采食量和能量消耗没有影响，因此饲料转化率和增重的改善是由于日粮中可消化赖氨酸需求的氨基酸平衡更好。根据体内蛋白质沉积确定，坦巴基幼鱼日粮中可消化赖氨酸的需要量为 1.58%，相当于日粮粗蛋白的 5.76%。