Cieslak D G, Benevenga N J
J Nutr. 1984 Oct;114(10):1863-70. doi: 10.1093/jn/114.10.1863.
A lysine-deficient amino acid mixture was developed by decreasing the level of lysine in a well-balanced amino acid mixture while measuring the response in daily gain and protein retention in young growing rats. The diet that contained the highest level of lysine that did not support maximal growth or protein retention was used as the lysine-deficient amino acid mixture. This mixture was incorporated into a series of diets to provide 0.52, 0.59 or 0.67% of lysine in combination with 0, 25 or 50% relative excess of all other amino acids. Food intake, weight gain and changes in carcass composition were measured in the 21-day feeding study. When voluntary food intake was used as a covariate in the statistical analysis, increased dietary lysine improved the efficiency of food use for body weight, dry matter, crude protein and ash gains. When corrected for food intake, lysine level did not affect lipid retention. There was no effect of excess amino acids on food intake, daily weight gain or body component gains whether food intake was used as a covariate or not. These results suggest that growing rats can respond to improved amino acid nutriture with changes in the efficiency of food use rather than improvements in growth.
通过降低营养均衡的氨基酸混合物中赖氨酸的水平，同时测量幼龄生长大鼠的日增重和蛋白质保留情况，开发出一种赖氨酸缺乏的氨基酸混合物。将不支持最大生长或蛋白质保留的最高赖氨酸水平的日粮用作赖氨酸缺乏的氨基酸混合物。将该混合物加入一系列日粮中，以提供0.52%、0.59%或0.67%的赖氨酸，并结合所有其他氨基酸0%、25%或50%的相对过量。在为期21天的喂养研究中测量食物摄入量、体重增加和胴体组成变化。在统计分析中将自愿食物摄入量用作协变量时，增加日粮赖氨酸可提高食物用于体重、干物质、粗蛋白和灰分增加的利用效率。校正食物摄入量后，赖氨酸水平不影响脂质保留。无论是否将食物摄入量用作协变量，过量氨基酸对食物摄入量、日增重或身体成分增加均无影响。这些结果表明，生长大鼠可通过改变食物利用效率而非生长改善来对氨基酸营养状况的改善做出反应。
