Two 100-day soybean meal crayfish experiments were conducted to evaluate effects of practical diets with different protein content and substitution possibilities of fish meal protein with soybean meal (SBM) protein on survival and growth of juvenile crayfish (Pacifastacus leniusculus) from the onset of exogenous feeding. In the first experiment, four practical diets were prepared to contain 35, 40, 45 or 50% crude protein. Results indicated that no differences in survival rates for crayfish fed 45 or 50% dietary protein and weight gain peaked at 45% crude protein.
In the second experiment, four practical crayfish diets (50% crude protein content) were prepared to test replacement levels of FM protein with 0, 24, 35, and 45% SBM. Replacement levels of 0% and 25% SBM enabled the highest survival (average: 74%) and growth rate. The researchers concluded that a 45–50% dietary protein with 25% replacement of fish meal protein by SBM protein can be recommended for juvenile P. leniusculus during the first period of intensive rearing.