Broiler chick responses to anorectic agents: 1. Dietary acetic and propionic acids and the digestive system.

The effects of various levels of acetic or propionic acid supplementation on feed intake and the gastrointestinal tract were studied in female broiler chicks. Voluntary feed intake and body weight gain decreased with the inclusion of the acids. Results indicate that acetic and propionic acids exert a similar anorectic effect on chicks fed diets differing in energy content. The inhibitory effect of these acids on voluntary feed intake could not be attributed to alterations in feed utilization, to differences in pancreatic alpha-amylase activity, or to differences in the acid-base balance. The increase in cecal capacity and volatile fatty acid (VFA) content is probably due to increased utilization of nonstarch polysaccharides at that site, the latter compensating for feed inhibition. This reflects a slight adaptive response of the cecum to anorectic agents.