Davis A T, Austic R E
J Nutr. 1982 Nov;112(11):2170-6. doi: 10.1093/jn/112.11.2170.
Experiments were conducted to determine the influence of dietary amino acids on the threonine requirement of chicks. A diet limiting in threonine and containing the equivalent of 20.6% crude protein was imbalanced by supplements of 0.9 to 1.5% L-tryptophan, 3.0% L-serine, a mixture of 2% each, leucine, isoleucine and valine or a 6.0% mixture of all essential amino acids but threonine. All amino acid supplements decreased the growth of chicks, and decreased food intake and/or efficiency of food utilization (P less than 0.05). Supplemental threonine prevented these effects in all cases except for 1.5% tryptophan in which the adverse effect of tryptophan was not prevented completely. The threonine requirement of Leghorn chicks was 0.69 to 0.72 percent of the diet when the diet did not contain the imbalancing amino acid supplements. We concluded that the threonine requirement of the chick is higher than previously reported, and is influenced by the amino acid content of the diet.
开展实验以确定日粮氨基酸对雏鸡苏氨酸需要量的影响。一种苏氨酸含量受限且粗蛋白含量相当于20.6%的日粮，通过补充0.9%至1.5%的L-色氨酸、3.0%的L-丝氨酸、亮氨酸、异亮氨酸和缬氨酸各2%的混合物或除苏氨酸外所有必需氨基酸的6.0%混合物而变得不平衡。所有氨基酸补充剂均降低了雏鸡的生长速度，并降低了采食量和/或食物利用效率（P小于0.05）。补充苏氨酸在所有情况下都可防止这些影响，但1.5%色氨酸的情况除外，其中色氨酸的不利影响未完全得到防止。当日粮不含有不平衡氨基酸补充剂时，来航雏鸡的苏氨酸需要量为日粮的0.69%至0.72%。我们得出结论，雏鸡的苏氨酸需要量高于先前报道的水平，并且受日粮氨基酸含量的影响。
