Applegate T J, Lilburn M S
Department of Animal Sciences, Ohio State University, Ohio Agricultural Research and Development Center, Wooster 44691, USA.
Poult Sci. 1996 Oct;75(10):1210-6. doi: 10.3382/ps.0751210.
Nicholas hens from the same flock were studied throughout the growing and laying periods. From 36 to 55 wk of age, 800 eggs were collected at approximately 5-wk intervals. At each age, a subsample of 100 eggs were randomly selected for egg weight, yolk weight, yolk DM, and yolk lipid (DM). The remaining 700 eggs were individually weighed and incubated. All eggs were reweighed at 25 d (transfer) and poults were individually weighted at hatch. At each sampling age, 50 poults were selected for analysis of yolk sac weight, yolk sac DM, and yolk sac lipid (DM). From 33 to 45 wk, mean hen BW decreased 0.9 kg. Across all ages, the relative weight of abdominal fat decreased more than that of the Pectoralis major. Relative yolk weight increased and relative albumen weight decreased with age. Yolk sac weight and lipid content (DM) of the poults at hatch increased markedly with age of hen. Across all ages, eggs were divided into weight classes. Initial egg weight had no effect on proportional moisture loss at 25 d or on relative poult weight at hatch. Egg moisture loss through 25 d was greatest in eggs from 36-wk-old hens compared with hens at 41, 45, 50, or 55 wk. Mean poult weight increased from 62.6 g at 36 wk to 64.9 g at 55 wk. Relative poult weight increased 3% from 36 to 55 wk when corrections for initial egg size were taken into consideration.
对来自同一鸡群的尼古拉斯母鸡在整个生长和产蛋期进行了研究。在36至55周龄期间，每隔约5周收集800枚鸡蛋。在每个年龄阶段，随机抽取100枚鸡蛋的子样本，用于测定蛋重、蛋黄重、蛋黄干物质和蛋黄脂质（干物质）。其余700枚鸡蛋分别称重后进行孵化。所有鸡蛋在25天（转移时）再次称重，雏鸡在出壳时单独称重。在每个采样年龄，选取50只雏鸡用于分析卵黄囊重量、卵黄囊干物质和卵黄囊脂质（干物质）。从33至45周，母鸡平均体重下降了0.9千克。在所有年龄阶段，腹部脂肪的相对重量下降幅度大于胸大肌。随着年龄增长，蛋黄相对重量增加，蛋白相对重量下降。雏鸡出壳时的卵黄囊重量和脂质含量（干物质）随母鸡年龄显著增加。在所有年龄阶段，鸡蛋被分为不同重量等级。初始蛋重对25天时的比例水分损失或出壳时的雏鸡相对重量没有影响。与41、45、50或55周龄的母鸡所产鸡蛋相比，36周龄母鸡所产鸡蛋在25天时的水分损失最大。雏鸡平均体重从36周时的62.6克增加到55周时的64.9克。考虑到初始蛋大小的校正后，从36至55周，雏鸡相对重量增加了3%。
