The mixture was filtered and washed with 200 ml of boiling water and NaOH (0.5 N). The residue was re-extracted, after washed with boiling distilled water and acetone and finally dried at 105°C to constant weight. The material was heated at 550°C for 3 h and the weight recorded. The moisture content was determined by drying the feed samples in an oven at 105°C until a constant weight was obtained. The ash content was obtained by calcinations in a muffle furnace at 550°C for 4 h. Proximate chemical composition of different feed ingredients used in Bangladesh for fish feed 867 Khan et al., Replacement of fish meal by plant protein sources in.