COMPARATIVE DEVELOPMENT OF DIGESTIVE ORGANS, INTESTINAL DISACCHARIDASES AND SOME BLOOD METABOLITES IN BROILER AND LAYER-TYPE CHICKS AFTER HATCHING

1. Body weight, digestive organ weights, and activities of disaccharid ases (maltase and saccharase) activities were determined from day of h atch to 21 d of age in meat- and egg-type chickens. Blood plasma was a nalysed for enzyme activities and metabolite concentration. 2. In meat -type chickens food intake and growth rate were about 3-fold those in egg-type chickens. Food efficiency was superior in meat-type chickens throughout the experimental period. 3. Meat-type chickens hatched with disaccharidase activities exceeding those found in their egg-type cou nterparts 2- to 5-fold. From 7 d of age on, this trend reversed, i.e. activity was much higher in egg-type than in meat-type chickens. 4. Bl ood plasma amylase activity increased gradually in meat-type chickens and was higher than in egg-type chickens to 14 d of age. No breed diff erences were observed for alkaline phosphatase or lactate dehydrogenas e activities during the experimental period. 5. Blood plasma concentra tions of total protein, albumin, glucose, and calcium, were lower in m eat than in egg-type chickens.