Protein Nutrition in Fish—VI Effects of Dietary Energy Sources on the Utilization of Proteins by Rainbow Trout and Carp

Abstract

The relationships between dietary energy sources and the utilization of dietary proteins have been investigated with rainbow trout and carp. In rainbow trout, lipid was utilized more effectively than carbohydrate (a-starch and dextrin) as an energy source for utilization of dietary protein. The values for PER and NPU of casein at low protein levels were markedly different according to the kind of energy sources used. Accordingly, the protein level producing the maximum growth rate also differed according to the main energy sources used. On the other hand, carp utilized carbohydrate effectively as an energy source. © 1976, The Japanese Society of Fisheries Science. All rights reserved.