Apparent digestibility coefficients for common feed ingredients in formulated diets for tropical catfish, Mystus nemurus (Cuvier & Valenciennes).

Apparent digestibility coefficients were determined for six feedstuffs, subsequent to their processing into pelleted feed for tropical freshwater catfish, Mystus nemurus (Cuvier & Valenciennes), using a reference diet and test diets composed of 70% reference diet and 30% test ingredient. It was found that most ingredients were fairly well digested except maize and chicken viscera. Digestibility coefficient for protein (P), dry matter (DM) and energy (E) were: (1) fish meal: 97.8% P, 97% DM. 77.88% E: (2) soybean meal: 86% P, 95.55% DM, 67.89% E: (3) rice bran: 81% P, 85.81% DM, 67.93% E: (4) copra meal: 79.90% P, 86% DM, 71.89% E: (5) maize: 51.93% P, 49.0% DM. 63.40% E and (6) chicken viscera: 37% P, 29% DM. 52% E. Digestibility coefficients for feedstuffs indicated that animal protein product, such as fish meal and grain by-product, such as rice bran were more digestible than starchy and fibrous feed, e.g. maize. Chicken viscera was poorly digested largely due to inefficient processing. As most feedstuffs were well digested, ingredient selection should, therefore, be based primarily on their protein content, amino acid composition and palatability. [ABSTRACT FROM AUTHOR]