Interactions of Dietary Levels of Protein and Energy on Channel Catfish (Ictalurus punctatus)

Abstract
Diets with 25 or 35% protein and various corn and fat levels were fed to satiation (ad libitum) and at a controlled rate to 14- and 114-g channel catfish (Ictalurus punctatus). Growth and feed conversion criteria demonstrated that larger fish require lower levels of protein and higher levels of energy than smaller fish. For 114- to 500-g fish 25% protein was adequate but for 14- to 100-g fish, 35% protein produced the faster gains. Corn (up to 25%) and fat (up to 12%) were equally effective as energy sources with digestible energy values of 2,700 and 6,780 kcal/kg, respectively. High dietary levels of protein and energy resulted in decreased feed consumption. Feed intake (% body weight/day) decreased from 5% for 114-g fish to 2% for 500-g fish. Body composition was influenced by ratio of dietary digestible energy to protein (DE/P). Protein deposition remained independent of diet while body moisture levels were negatively correlated and body fat levels were positively correlated to DE/P ratios. Effects of DE/P ratios on body composition of channel catfish were similar to those reported for the chicken but the magnitude of the effects was not as great for catfish as reported for chickens.