Mills A D, Marche M, Faure J M
Br Poult Sci. 1987 Mar;28(1):177-81. doi: 10.1080/00071668708416950.
The incidence of eggs showing abnormal shell calcification amongst those produced by hens kept in individual battery cages, hens kept in battery cages in groups of 3 and hens kept in battery cages in groups of 4 was studied. There was good agreement between observers in the assessment of abnormal eggs. Hens kept in individual cages laid fewer abnormal eggs than hens kept in groups of 3 or 4. There was no significant difference in the incidence of abnormal eggs between hens kept in groups of 3 or 4. The results of this study support the idea that the incidence of eggs showing abnormal calcification may provide a quick and reliable method of measuring stress in hens which lay brown shelled eggs.
研究了饲养在单个层架式鸡笼中的母鸡、饲养在每组3只的层架式鸡笼中的母鸡以及饲养在每组4只的层架式鸡笼中的母鸡所产鸡蛋出现蛋壳钙化异常的发生率。在异常鸡蛋的评估方面，观察者之间的意见高度一致。饲养在单个鸡笼中的母鸡所产异常鸡蛋比饲养在每组3只或4只鸡笼中的母鸡少。饲养在每组3只或4只鸡笼中的母鸡所产异常鸡蛋的发生率没有显著差异。本研究结果支持这样一种观点，即出现钙化异常的鸡蛋发生率可能为测量产褐壳蛋母鸡的应激提供一种快速可靠的方法。
