Keshavarz K, Jackson M E
Department of Animal Science, Cornell University, Ithaca, New York 14853.
Poult Sci. 1992 May;71(5):905-18. doi: 10.3382/ps.0710905.
An experiment was conducted to determine the effect of feeding low-protein, amino acid-supplemented diets during growing and laying periods on performance of a commercial strain of White Leghorn chickens. The birds of the positive control were fed diets in a sequence of 20, 16, and 14% protein during 0 to 6, 6 to 12, and 12 to 18 wk (growing period) and of 18, 16.5 and 15% protein during 18 to 34, 34 to 50, and 50 to 66 wk of age (laying period). The birds of the negative control were fed protein levels of 16, 13.5, and 11.5% in the growing period and 14, 13, and 12% in the laying period. Other groups were fed the negative control series supplemented with methionine, methionine plus lysine, or methionine plus lysine plus other deficient essential amino acids. An additional group was fed the negative control supplemented with methionine plus lysine during the growing period and a protein sequence of 15, 14, and 13% supplemented with methionine and lysine during the laying period. At 18 wk of age, birds fed the negative control supplemented with methionine plus lysine or methionine plus lysine plus other deficient essential amino acids had comparable body weight to those fed the positive control despite significantly lower protein and lysine intake. Overall egg production and egg weight of birds fed the sequence of 14, 13, and 12% protein supplemented with combination of methionine, lysine, and extra levels of tryptophan and isoleucine or of the birds fed the sequence of 15, 14, and 13% protein supplemented with methionine and lysine were not different from those fed the positive control. However, egg mass and body weight were inferior to those of birds fed the positive control.
进行了一项实验，以确定在生长和产蛋期饲喂低蛋白、补充氨基酸的日粮对商用白来航鸡品种性能的影响。阳性对照组的鸡在0至6周、6至12周和12至18周（生长期）分别饲喂蛋白质含量为20%、16%和14%的日粮，在18至34周、34至50周和50至66周龄（产蛋期）分别饲喂蛋白质含量为18%、16.5%和15%的日粮。阴性对照组的鸡在生长期饲喂的蛋白质水平分别为16%、13.5%和11.5%，在产蛋期分别为14%、13%和12%。其他组饲喂补充了蛋氨酸、蛋氨酸加赖氨酸或蛋氨酸加赖氨酸加其他缺乏的必需氨基酸的阴性对照系列日粮。另外一组在生长期饲喂补充了蛋氨酸加赖氨酸的阴性对照日粮，在产蛋期饲喂补充了蛋氨酸和赖氨酸的蛋白质含量为15%、14%和13%的日粮。在18周龄时，饲喂补充了蛋氨酸加赖氨酸或蛋氨酸加赖氨酸加其他缺乏的必需氨基酸的阴性对照日粮的鸡，尽管蛋白质和赖氨酸摄入量显著较低，但其体重与饲喂阳性对照日粮的鸡相当。饲喂补充了蛋氨酸、赖氨酸以及额外水平色氨酸和异亮氨酸的蛋白质含量为14%、13%和12%的日粮序列的鸡，或饲喂补充了蛋氨酸和赖氨酸的蛋白质含量为15%、14%和13%的日粮序列的鸡，其总产蛋量和蛋重与饲喂阳性对照日粮的鸡没有差异。然而，蛋重和体重低于饲喂阳性对照日粮的鸡。
