Shanawany M M
Br Poult Sci. 1984 Oct;25(4):449-55. doi: 10.1080/00071668408454886.
A clear positive correlation was evident between egg weight at setting and embryo weight at 18 d of incubation for eggs laid at or after 32 weeks of age. The weight of embryos from the same size eggs were found to depend upon a curvilinear function of the age of parent flock, with the largest increase in embryo weight occurring between 28 and 32 weeks of age. Hatching weight was highly correlated with egg size at setting. Flock age had no effect on hatching weight from a particular sized egg. Within any of the five ages studied, chicks from smaller eggs tended to hatch slightly (but not significantly) earlier than those from larger eggs.
对于32周龄及以后产的蛋，入孵时蛋重与孵化18天时胚胎重量之间存在明显的正相关。发现来自相同大小蛋的胚胎重量取决于亲代鸡群年龄的曲线函数，胚胎重量增加最大的阶段出现在28至32周龄之间。出雏重与入孵时的蛋大小高度相关。鸡群年龄对特定大小蛋的出雏重没有影响。在所研究的五个年龄阶段中的任何一个阶段内，较小蛋孵出的雏鸡往往比来自较大蛋的雏鸡稍微早一点（但不显著）出壳。
