Replacement of fish meal by pea protein concentrate in practical diets for juvenile crayfish (Pacifastacus leniusculus Dana, Astacidae) from the onset of exogenous feeding

Abstract

The aim of this study was to evaluate different replacement levels of fish meal (FM) with pea protein concentrate (PPC) on survival and growth of juvenile crayfish (Pacifastacus leniusculus). A 100-day experiment was conducted with stage 2 juveniles from the onset of exogenous feeding. Four practical diets (50% crude protein) differing in the level of replacement of FM protein by PPC protein were prepared: 0% (control diet), 25% (20.2% dietary PPC), 35% (28.2% dietary PPC) or 45% (35.5% dietary PPC). Each diet was tested on grouped or individually isolated crayfish. The 25% or 35% replacement of FM protein by PPC protein resulted in survival (average of grouped and isolated: 83.6%) and growth (grouped and isolated: 14.44mm carapace length, 674.9mg weight) similar to those obtained with the control diet. Final growth of isolated crayfish was significantly higher than that of grouped crayfish with all diets. The relation among the amino acid profile of the diets, the performance of juveniles and the amino acid requirements determined for other crustacean species is discussed. The present study provides the first data on the substitution possibilities of FM by PPC in diets for freshwater crayfish. A 28.2% PPC (35% replacement of FM protein) can be included in formulated diets (50% crude protein) for juvenile P. leniusculus during the first 100days of intensive rearing without impairing growth or feed conversion.