Adrenocortical function in fasted-refed birds

Abstract

Concentrations of plasma corticosterone were increased in 6–8 week old chickens after a 48 h fast. When allowed to feed ad libitum the concentration declined to the prefasting level within 30 min. A similar decline in the corticosterone level was also observed when fasted birds were refed 1, 5, 15 or 30 g of diet although the duration of suppression was directly related to the amount of food consumed. Adrenocortical suppression was also induced by glucose administration and by force feeding synthetic diets of differing energy content. The causal effect of nutritional stimuli on adrenocortical suppression was shown by the duration of suppression being related to dietary energy content. Although force-feeding an inert cellulose diet had no effect on corticosterone secretion, some adrenocortical suppression was observed when fasted birds were allowed to consume cellulose or sand ad libitum. The possibility that visual stimuli may contribute to adrenocortical suppression following refeeding was shown by a reduction in the corticosterone concentration in fasted birds given sight of, but not access to, food. Sight of a pelleted diet for as little as 5 min was effective in suppressing the levels of plasma corticosterone, although continued sight of food for 4 h was ineffective. These results demonstrate that both visual and metabolic stimuli are effective in causing adrenocortical suppression in fasted chickens presented with food. © 1984 Taylor and Francis Group, LLC.