鱼类对蛋白质的需要实际上是对必需氨基酸的需要,蛋白质营养平衡实际上是氨基酸的平衡。饲料中一旦缺乏某种氨基酸,会使构成蛋白质的各种氨基酸比例失调,限制其它氨基酸的利用,多余的氨基酸则脱掉氨基作为能量被消耗掉,从而造成蛋白质利用不合理。但是所有的植物蛋白都存在某种或某几种限制性氨基酸,其中最主要的为蛋氨酸和赖氨酸,因此,当饲料中植物蛋白源的添加量逐渐升高 Fish’s need for protein is actually a requirement for essential amino acids, and the balance of protein nutrition is actually the balance of amino acids. The lack of a certain amino acid in the feed will make the various amino acids constituting the protein imbalance, limiting the use of other amino acids, leaving excess amino acids as energy is consumed, resulting in unreasonable protein utilization. However, all the plant proteins contain one or several restricted amino acids, of which methionine and lysine are the most important. Therefore, when the amount of plant protein source in the feed gradually increases