Metabolic Response to Restricted Feeding of a High Protein Diet in Common Carp

Abstract

The effect of feeding rate on the hepatopancreatic enzyme activities and body composition in carp was studied by feeding a high protein diet at different feeding rates (100, 70, 30, and 0% of satiation). As the feeding rate decreased, so did the hepatopancreatic glycogen and crude fat contents, as well as serum triglyceride, phospholipid, cholesterol, glucose, free amino acid, and total protein levels. Serum free fatty acid level was higher in the 0% (starvation) group than in the other feeding groups. The activities of dehydro-genases in the pentosephosphate cycle and amino acid degrading enzymes showed decreasing tendencies as the feeding rate decreased, while almost no changes were detected in the activities of glucose-6-phosphatase, pyruvate kinase, and NADP-malate dehydrogenase. These results suggest that severe restricted feeding of a high protein diet depresses amino acid catabolism and lipogenesis and stimulates glycogen and fatty acid mobilization, but maintains glycolysis and gluconeogenesis. © 1993, The Japanese Society of Fisheries Science. All rights reserved.