Christmas R B, Harms R H
Poult Sci. 1983 Feb;62(2):389-91. doi: 10.3382/ps.0620389.
Two strains of White Leghorn hens were subjected to seven copper treatments that included a negative control for the first week of each of five 28-day periods. The hens were approximately 500 days of age when the experiment began. Copper treatments were assigned to simulate the different levels of copper intake that might result from differences in daily feed intake similar to the practice followed with commercial industry. In order to simulate daily dietary intake ranging from a low of 73 to a high of 136 g per bird, levels of 76, 91, 100, 114, 129, and 143 mg of copper sulfate per kilogram were added to each of the basal diets. Treatments were administered across two methionine levels in a corn-soy basal diet. Hen-day egg production, egg weight, daily feed intake, and feed efficiency values were not affected by dietary levels of copper or methionine. Hens fed diets containing low methionine laid eggs with significantly poorer specific gravity.
选用两株白来航母鸡，进行了七种铜处理，在五个28天周期中的每个周期的第一周设置了一个阴性对照。实验开始时，母鸡约500日龄。进行铜处理是为了模拟因每日采食量差异可能导致的不同铜摄入量水平，这与商业行业的做法类似。为了模拟每只鸡每天73克至136克的低至高的日粮摄入量，在每种基础日粮中添加了每千克76、91、100、114、129和143毫克的硫酸铜水平。在玉米 - 大豆基础日粮中，在两种蛋氨酸水平下进行处理。母鸡日产蛋量、蛋重、每日采食量和饲料效率值不受日粮铜水平或蛋氨酸水平的影响。饲喂低蛋氨酸日粮的母鸡所产蛋的比重明显较差。
