Evaluation of practical diets containing different protein levels, with or without fish meal, for juvenile Australian red claw crayfish (Cherax quadricarinatus)

Six practical diets containing increasing percentages of crude protein (CP) (30%, 35%, and 40%) with or without anchovy fish meal (FM) were fed to juvenile red claw crayfish (mean individual weight=1.12 g) during an 8-week feeding trial. Growth, survival, feed conversion ratio, and amino acid composition of tail-muscle meat of juvenile red claw were determined. At the conclusion of the experiment, specific growth rate (SGR) and percent survival among treatments, which averaged 3.91%/day and 80.7%, overall, were not significantly different among treatments. The percent weight gain of red claw fed a diet containing 20% fish meal and 40% crude protein was significantly higher (1352%) than that of red claw fed a diet containing 0% fish meat and 30% crude protein (828%), but not different from red claw fed all other diets. Red claw fed Diet 3 had significantly higher FCR (5.73) compared to red claw fed Diet 6 (3.03) but not different from red claw fed the other four diets. Results from this study indicate that juvenile red claw can be fed a practical diet containing 35% CP with 0% FM if a combination of less expensive plant protein ingredients (SBM, wheat, BGY, and milo) is added. CP levels can be reduced to 30% if 15% anchovy fish meal is included. Reducing CP levels and the reliance of fish meal in Australian red claw diets may help reduce operating costs and thereby increase producers profits. (C) 2004 Elsevier B.V. All rights reserved.