1. Body weight and the weight of the digestive organs and activities of some digestive enzymes were determined from hatching to 23 d of age. 2. Relative daily growth rate peaked at 11 d of age (22% gain/d) and then decreased gradually. 3. The vitelline residue was decreased rapidly from 4.6 g at hatching to negligible values from 4 d of age. 4. Maximal allometric growth of the pancreas and small intestine was 4-fold and that of liver 2-fold greater than that of the body. 5. Activities (units/kg body weight) of the digestive enzymes measured in the pancreas and intestinal contents increased with age. In the pancreas maximal values were attained on day 8 for amylase and lipase and 11 for trypsin and chymotrypsin. In the small intestine maxima were attained on day 4 for lipase, 11 for trypsin and chymotrypsin and 17 for amylase. 6. The development of secretion of digestive enzymes in the post-hatched chick could be a limiting factor in digestion and subsequently in food intake and growth.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.