Nutritional evaluation of various plant protein sources in diets for Asian sea bass Lates calcarifer

Abstract

A biological assay was conducted to evaluate the suitability of various leguminous seed meals and leaf meals as dietary protein sources for Asian sea bass, Lates calcarifer. In the growth experiment, fish (initial mean weight ± standard error (SE) of 3.8 ± 0.5 g) were fed isonitrogenous and isocaloric diets containing test ingredients to replace 13–18% of the diet. The same diet formulations were used in a digestibility experiment, except that 1% Cr₂O₃ was added as an external indicator. The growth of the control fish was comparable to fish fed leguminous seed meal-based diets, and better than those given leaf meal-based diets. The control diet had the highest apparent protein digestibility (APD) value. No significant differences were observed between the APD of white cowpea (Vigna unguiculata), green mungbean (V. radiata) and papaya (Carica papaya) leaf meal-based diets. However, the cassava (Manihot esculenta) leaf meal-based diet had the lowest APD value. The present findings suggest that white cowpea and green mungbean meals can be used as protein sources in practical diets to replace 18% of the sea bass diet without affecting their growth.