Optimum Ratio of Dietary Protein to Energy for Red Crayfish (Procambarus clarkii)

Abstract

Abstract Six experimental diets were formulated with protein-to-energy (P:E) ratios ranging from 57 to 160 mg protein/kcal. The diets, which were fed to juvenile red crayfish, contained either 20, 30, or 40% crude protein and 2.5 or 3.5 kcal of total energy per gram of diet. As dietary energy increased, growth of crayfish fed the 30% protein diets decreased, but growth of crayfish fed the 40% protein high-energy diets increased. In general, the percentage of body protein (wet weight) decreased as dietary energy increased. Crayfish fed low-energy (low-fat) diets had lower percentages of body fat. Also, body fat tended to decrease as dietary protein increased. Best growth and protein deposition were observed in crayfish fed a diet with a P:E ratio of 120 mg protein/kcal; this diet contained 30% crude protein and 2.5 kcal/g dietary energy.