The effects of restricted feeding on adrenal cortical activity in the immature domestic fowl.

1. The effect of reducing food intake to 75% of the ad libitum intake was determined from hatching to 8 weeks in young Light Sussex chickens. 2. Restricted birds were lighter throughout the experiment. 3. Relative adrenal weight tended to be greater in restricted birds but the difference decreased with time. 4. There was no depletion of adrenal cholesterol: from week 5 there was a significantly greater amount in the adrenals of restricted birds. 5. After 1 week of restriction plasma corticosterone concentration was 73% greater than in controls. It decreased progressively, falling within the normal range at 5 weeks. 6. Restricted birds were hypoglycaemic from weeks 2 to 7 and hyperlipacidaemic throughout. A negative correlation between plasma glucose and free fatty acids was found.