Factors affecting food intake in the domestic chicken: the effect of infusions of nutritive and non-nutritive substances into the crop and duodenum.

1. Infusions of 10 g of diet mashed in 20 ml of water, increasing glucose loads and hypertonic solutions of glucose, sorbitol and KCl, were introduced into the crop of the adolescent cockerel (1.5 to 2.0 kg body weight and 12 to 20 weeks of age). All caused a significant reduction of food intake over the following 3-h period. 2. Duodenal infusions of hyperosmotic solutions of sorbitol and KCl at 3 osm significantly decreased food intake within an hour of infusion. Glucose infusion decreased intake only in birds starved for 3 h before the experiment. 3. The results are discussed in relation to the site of infusion and nutritive visceral mechanisms of food intake control. It is likely that there is a major osmotic control in the duodenum which may affect a secondary control system in the upper gastro-intestinal tract.