Christmas R B, Douglas C R, Kalch L W, Harms R H
Poult Sci. 1982 Oct;61(10):2103-6. doi: 10.3382/ps.0612103.
A total of 6000 layer-type pullet chicks were fed either a low protein (9.1%) or a high protein (15.4%) diet from 8 through 18 weeks of the growing period in two experiments. All chicks were fed a commercial starter for the first 8 weeks and the high protein diet from 18 to 21 weeks of age. All chicks were grown in floor pens and were supplied feed and water ad libitum throughout the growing trial. They were placed in either a cage- or floor-laying house and fed a commercial layer diet for 12 periods of 28 days each. The experiment was repeated in the subsequent year. The low protein regimen was found to produce a smaller pullet, delay sexual maturity, delay production peaks, and maintain higher levels of production near the end of the laying period. Pullets fed the low protein grower diet had higher mortality during the growing period, greater feed intake during the laying period, eggs with higher Haugh unit values, and reduced egg production in the laying house.
在两项实验中，共6000只蛋用小母鸡从8周龄至18周龄的生长阶段分别饲喂低蛋白（9.1%）或高蛋白（15.4%）日粮。所有雏鸡在最初8周饲喂商品育雏料，18至21周龄饲喂高蛋白日粮。所有雏鸡在地面围栏中饲养，在整个生长试验期间自由采食和饮水。它们被安置在笼养或地面平养的产蛋鸡舍中，饲喂商品蛋鸡日粮，每个周期为28天，共12个周期。该实验在次年重复进行。结果发现，低蛋白日粮方案会使小母鸡体型较小、性成熟延迟、产蛋高峰推迟，并在产蛋期接近尾声时保持较高的产蛋水平。饲喂低蛋白生长鸡日粮的小母鸡在生长期间死亡率较高，产蛋期采食量较大，所产鸡蛋哈夫单位值较高，且在产蛋鸡舍中产蛋量减少。
