title: Extraneous egg shell calcification as a measure of stress in poultry.
abstract: 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.
mesh_terms: D000818:Animals; D002113:Calcification, Physiologic; D002645:Chickens / Q000502:physiology*; D004528:Egg Shell; D005260:Female; D011201:Poultry Diseases / Q000503:physiopathology*; D013312:Stress, Physiological / Q000503:physiopathology / Q000662:veterinary*