Fancher B I, Jensen L S
Department of Poultry Science, University of Georgia, Athens 30602.
Poult Sci. 1989 Oct;68(10):1385-95. doi: 10.3382/ps.0681385.
Three experiments were conducted to determine the effects of dietary CP, essential amino acid (EAA), and K content upon male broiler performance during starting and growing periods (7 to 21 and 21 to 42 days, respectively). In Experiment 1, five grower diets formulated to be equal in K content and containing the following analyzed CP contents were used: 21.9, 19.1, and 16.2% with and without L-glutamic acid (GLU) supplementation or 10% increased levels of arginine (ARG), threonine (THR), isoleucine (ILE), and tryptophan (TRP). Seven diets containing the following analyzed CP contents were fed in Experiment 2: 21.5%, 19.6% with and without K supplementation, and 16.0% with and without K supplementation and/or 10% increased levels of ARG, THR, ILE, and TRP. In Experiment 3, four starter diets containing the following CP contents were fed: 24.5%, and 17.8% without and with added K. In all three experiments feed efficiency (FE) was lower and in Experiments 1 and 2, abdominal fat deposition (AFD) was higher with lower levels of dietary CP. Lower body weight gains (BWG) occurred with lower levels of dietary CP in Experiments 2 and 3, but not in Experiment 1. Adding extra ARG, THR, ILE, and TRP to the lowest CP diet sometimes improved FE, but had no effect on BWG or AFD. Supplementation with GLU or K failed to influence BWG or FE. However, addition of GLU was associated with lower AFD. Maximal performance generally was not obtained with the low CP, amino acid-fortified diets.
进行了三项试验，以确定日粮粗蛋白（CP）、必需氨基酸（EAA）和钾含量对雄性肉鸡育雏期和生长期（分别为7至21日龄和21至42日龄）生产性能的影响。在试验1中，使用了五种钾含量相同、分析粗蛋白含量如下的生长鸡日粮：21.9%、19.1%和16.2%，添加和不添加L-谷氨酸（GLU），或精氨酸（ARG）、苏氨酸（THR）、异亮氨酸（ILE）和色氨酸（TRP）水平提高10%。试验2饲喂了七种分析粗蛋白含量如下的日粮：21.5%、19.6%，添加和不添加钾，以及16.0%，添加和不添加钾和/或ARG、THR、ILE和TRP水平提高10%。在试验3中，饲喂了四种粗蛋白含量如下的雏鸡日粮：24.5%，以及17.8%，不添加和添加钾。在所有三项试验中，日粮粗蛋白水平较低时，饲料效率（FE）较低，在试验1和试验2中，腹脂沉积（AFD）较高。在试验2和试验3中，日粮粗蛋白水平较低时体重增加（BWG）较低，但在试验1中并非如此。在最低粗蛋白日粮中添加额外的ARG、THR、ILE和TRP有时可提高FE，但对BWG或AFD无影响。补充GLU或钾未能影响BWG或FE。然而，添加GLU与较低的AFD有关。低粗蛋白、氨基酸强化日粮通常无法获得最佳生产性能。
