Evaluation of soybean mealas a protein source and its effect on growth and nitrogen utilization of Black Sea turbot (psetta maeotica) juveniles

Abstract

Three experimental diets were formulated to be isonitrogenous (550 g kg-1 protein) and iso-caloric (20.5 kJ gross energy g-1 diet) by substituting fish meal (FM) for defatted soybean meal (SBM) at levels of 0, 10 and 20% replacement in order to evaluate the effects of replacing FM with defatted SBM in diets for Black Sea turbot. Diets were fed to triplicate groups of young Black Sea turbot (mean initial weight of 30.2 ± 0.2 g) for 60 days. Turbot fed all three diets had no significant difference (P > 0.05) in final weight, specific growth rate, nutrient utilization, Nitrogen loss or retention. Survival rate was 100% in all treatments. The results of this study indicate that fish meal can be replaced with soybean meal up to 20% level in diets for young Black Sea turbot without adverse effects on growth, nutrient utilization or nitrogen balance. This may increase profitability by allowing the production of less expensive feeds, hence supporting the sustainable growth of turbot culture industry with environment-friendly diets.