斑节对虾的精氨酸、蛋氨酸、苯丙氨酸、色氨酸的需求量研究

REQUIREMENTFOR DIETARYARGININE,METHIONINE,PHENYLALANINEAND TRYPTOPHANBYJUVENILEOF THESHRIMPPENAEUSMONODON

用额外添加必需氨基酸的实验饲料投喂斑节对虾虾苗，研究斑节对虾的精氨酸、蛋氨酸、苯丙氨酸、色氨酸的需求量。添加精氨酸，对虾的增重明显，并且随着添加量的增大，对虾的增重率也变大，但不影响成活率。当精氨酸占饲料中蛋白质含量的１０．３８％时，对虾的增重率、成活率都最高，这时饲料的必需氨基酸比率（Ａ／Ｅ）与对虾肌肉必需氨基酸比率相似。添加蛋氨酸后，对虾的增重率、成活率明显升高，烂尾率明显下降至消失，但三个水平之间差异不显著（Ｐ＜０．０５）。蛋氨酸占蛋白质比为４．２４％时，能获得最大的增重率并消除烂尾。饲料中添加苯丙氨酸达一定量时（占蛋白质比为８．３０％），增重率（比不加苯丙氨酸的）差异显著；但苯丙氨酸加到１０．９６％时，对虾的生长反而受到影响。饲料中缺乏精氨酸和苯丙氨酸都影响增重，但不引起死亡和烂尾。饲料中加入色氨酸，对虾的增重率无甚变化，含量低时（０．５８％和０．９６％）烂尾率较高。但当色氨酸含量为１．３５％时却能获得最大的增长并消除烂尾。

Juveniles of Shrimp Penaeus monodon(mean body weight 0.5g)were fed basaldiets with three levels of Arginine,Methionine,Phenylalanine and Tryptophan.The studywas conducted on the requirements of shrimp for the above essential amino acids.The additionof Arginine improved body weight significantly but had no effect on survival rate.The weihtgain and the addition of Arginine are in direct proportion. When the protein in the diet addedwith Arginine was 10.38%,the weight gain and survival rate reached a maximum,The es-sential amino acid ratio(A/E)was similar to the ratio of meal to the essential amino acids withthe addition of Methionine,the weight qain and survival rate increased and the rate of caudalfin erosion decreased significantly or even disappeared.There was no significant difference inweight gain and survival rate among the three levels(P<0.05)when the protein in the dietadded with Methonine was 4.24%,the weight gain reached a maximum and the rate of caudalfin erosion disappeared.when a certain amount of Phenylalanine(8.30%of protein)wasadded in the diet,there was a signifieant difference in weight gain compared with the dietwithout Phenylalanine;but with the addition of Phenylalanine(10. 96%),shrimp growithwas affected thus the weight gain decrensing.Deficiency of Arginine and Phenylalanine re-duced the weight gain (P<0.05),without any effect on mortality or caudal fin erosion.Theaddition of tryptophan had no significant effect on weight gain(P<0.05),but the low con-tents of tryptophan(0.58%and 0. 96%)resulted in caudal fin erosion. when the Tryptophancontent was 1.35%,the weight gain reached a maximum and caudal fin erosion disappeared.