Applegate T J, Harper D, Lilburn M S
Department of Animal Sciences, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster 44691, USA.
Poult Sci. 1998 Nov;77(11):1608-12. doi: 10.1093/ps/77.11.1608.
At 26, 31, 36, and 42 wk of age, eggs were collected from the same duck breeder flock to study the effects of hen production age on egg composition and embryo development. At each hen age, yolk and albumen measurements were made on a random subsample of unincubated eggs. Embryo and yolk sac measurements were made at 20, 22, 24, 26, 27, and 28 d of incubation. Egg weight was significantly affected by hen production age, but most of the observed age effects occurred between 26 and 31 wk with minimal age differences thereafter due to a quantitative feed restriction for egg weight. Yolk weight increased significantly with hen production age, with the largest increase, 6.6 g, also occurring between 26 and 31 wk of age. Yolk-free duckling weight increased with hen production age at 27 d of incubation. The yolk sacs of embryos from the 31-, 36-, and 42-wk-old hens were heavier at 20 and 22 d, before the differentiation in embryo weight. Differences in yolk sac weight were not consistently affected by hen production age between 26 and 28 d of incubation. The eggs from the 42-wk-old hens weighed 3.3 g less than those from the 31-wk-old hens, but yolk-free duckling weight at 27 d was 2.9 g heavier from the 42-wk-old hens.
在26、31、36和42周龄时，从同一批种鸭群中收集种蛋，以研究母鸡产蛋年龄对蛋的组成和胚胎发育的影响。在每个母鸡产蛋年龄阶段，对未孵化种蛋的随机子样本进行蛋黄和蛋白测量。在孵化的第20、22、24、26、27和28天对胚胎和卵黄囊进行测量。蛋重受母鸡产蛋年龄的显著影响，但大多数观察到的年龄效应发生在26至31周之间，此后由于对蛋重进行定量限饲，年龄差异最小。蛋黄重量随母鸡产蛋年龄显著增加，最大增加量为6.6克，也发生在26至31周龄之间。孵化27天时，去黄雏鸭体重随母鸡产蛋年龄增加。在胚胎体重分化之前，31周龄、36周龄和42周龄母鸡所产胚胎的卵黄囊在20天和22天时较重。在孵化26至28天期间，卵黄囊重量的差异并不总是受母鸡产蛋年龄的影响。42周龄母鸡所产的蛋比31周龄母鸡所产的蛋轻3.3克，但42周龄母鸡所产蛋孵化27天时去黄雏鸭体重重2.9克。
