论文部分内容阅读
为了评价虹鳟日粮添加蛋氨酸的作用,我们用5种日粮进行试验:日粮1基础日粮含50％酪蛋白作为蛋白源,日粮2～4分别添加0.5、1.0和1.5％的L—蛋氨酸于基础日粮,日粮5用50％的蛋清作为蛋白源。饲喂添加蛋氨酸日粮鱼肝脏和肌肉中蓄积大量的蛋氨酸。不同蛋氨酸含量肝脏中氨基乙磺酸含量受日粮处理的影响甚微。日粮中添加1.0％蛋氨酸时,蛋白质净利用值(NPU)得到提高,而添加1.5％时,其NPU比添加量1.0％的日粮低。表明,虹鳟鱼将蛋氨酸通过硫化作用转换为半胱氨酸能力是有限的,添加过量的蛋氨酸日粮,虹鳟不能有效利用。
In order to evaluate the role of methionine in rainbow trout diets, we used five kinds of diets: the basal diets containing 50% casein as the protein source, and the diets 2-4 added 0.5, 1.0 and 1.5% L- Methionine in the basal diet, diet 5 with 50% egg white as a protein source. Feeding added methionine diet fish liver and muscle accumulation of large amounts of methionine. Different methionine levels in the liver of the amino acid content of dietary treatment has little effect. When 1.0% methionine was added to the diets, the net protein value (NPU) was increased, while at 1.5%, the NPU was lower than the ration of 1.0%. The rainbow trout’s capacity to convert methionine to cysteine by sulphurization is limited, and rainbow trout can not be used efficiently with the addition of excess methionine diet.