Adrenal Weight, Adrenal Ascorbic Acid, Adrenal Cholesterol and Differential Leucocyte Counts as Physiological Indicators of “Stressor” Agents in Laying Hens

Abstract

IT IS thought that the adrenal cortex assumes an important role in an animal’s ability to overcome environmental influences. Therefore, assays capable of indicating adrenal cortical function following changes in management, feed, lighting schedules and weather, among other factors, would possibly be a step toward the elimination of production decreases. Research with rats and guinea pigs (reviewed by Sayers, 1950) has shown that depletion of adrenal ascorbic acid, cholesterol and lipid contents occurs following an injection of pituitary adrenotropic hormone and following stressful conditions such as excessive muscular work or a non-fatal hemorrhage. Reports involving “stressor” agents and their influence on the avian adrenal have been more inconsistent than the reported influence on the mammalian adrenal. Howard and Constable (1958) and Siegel and Beane (1961) produced adrenal cholesterol depletion in chickens following ACTH injection; however, Elton et al. (1959) reported that adrenal cholesterol remained unchanged following ACTH and cold (0–5 …