VARIATIONS OF INTESTINAL MALTASE AND SUCRASE ACTIVITIES IN CHICKS ACCORDING TO AGE AND DIET

The maltase and sucrase activities of 4 and 8-week old chickens were measured in the duodenum, jejunum and ileum. Semi-synthetic diets were given from hatching. They were isoenergetic, but had different carbohydrate contents: 61% starch, 61% sucrose, carbohydrate-free (35% cellulose, 26% fat). A commercial type diet was given to a control group. The chickens were fasted 14 hrs before decapitation. Disaccharidase activities were maximal in the jejunum. The highest activities were observed with the two carbohydrate diets. Sucrose had a greater effect on the proximal parts of the intestine: the duodenum and jejunum. In the ileum, disaccharidase activities were greater with the starch diet. Activity in the carbohydrate-free diet was less than 50%. The commercial diets gave intermediate results between the carbohydrate and carbohydrate-free diets. The diets affected disaccharidase activities, nd their influence was evident whether the enzyme activities were expressed as units per tissue protein or as units per wet weight. The response, however, was not specific. The activities of maltase and sucrase increased concomitantly. Carbohydrate stimulation tended to decrease from 4 to 8 weeks of age.