摘要: 研究在海兰褐蛋鸡育肥日粮中添加不同蛋白质水平对其生产性能和蛋品质的影响。随机选取180只海兰褐蛋鸡分为3组，每组又分为5个试验组，每个试验组12只，设计3个不同的蛋白质水平，试验组A、B、C育肥期日粮蛋白质水平分别为14%、16%、18%，试验组B、C育肥期日粮蛋白质水平分别为16%、18%。从7周龄至开始产蛋分别饲喂不同蛋白质水平的日粮，开始产蛋后各组饲喂相同的商品日粮。试验分为两个阶段：第一阶段为育肥期（7～19周龄），第二阶段为产蛋期（20～26周龄）。从20周龄开始统计母鸡的产蛋性能，并在20、26周龄测定蛋品质。结果表明：试验B、C组产蛋率显著高于试验A组（P < 0.05）；试验B组平均蛋重高于试验A、C组，但大多数情况下这种差异并不显著。在蛋品质方面，试验组B的蛋壳强度、蛋形指数、蛋白质高度和哈氏单位均显著高于试验A、C组（P<0.05）。

Abstract: The effects of different protein levels in fattening diet of Hy-Line brown laying hens on production performance and egg quality were studied. 180 Hy-Line brown laying hens were randomly selected and divided into 3 groups, each of which was further divided into 5 experimental groups, with 12 hens in each experimental group. 3 different protein levels were designed. The protein levels of the fattening diets of experimental groups A, B, and C were 14%, 16%, and 18%, respectively, and the protein levels of the fattening diets of experimental groups B and C were 16% and 18%, respectively. From 7 weeks of age to the start of egg laying, the groups were fed with diets of different protein levels. After the start of egg laying, the groups were fed with the same commercial diet. The experiment was divided into two stages: the first stage was the fattening period (7-19 weeks of age), and the second stage was the egg laying period (20-26 weeks of age). The egg laying performance of the hens was counted from 20 weeks of age, and the egg quality was measured at 20 and 26 weeks of age. The results showed that the egg production rate of test groups B and C was significantly higher than that of test group A (P < 0.05); the average egg weight of test group B was higher than that of test groups A and C, but in most cases this difference was not significant. In terms of egg quality, the eggshell strength, egg shape index, protein height and Haugh unit of test group B were significantly higher than those of test groups A and C (P < 0.05).