Replacement of fish meal with two fermented soybean meals in diets for rainbow trout (Oncorhynchus mykiss)

Abstract

The present study investigated the effect of fish meal (FM) replacement with fermented soybean meal (FSM) on growth and feed utilization of rainbow trout. Two FSM products, FSM1 (more fermentation with more small peptide and acid than FSM2) and FSM2 were used to replace 20%, 40% and 60% of FM in control diet (250 g/kg FM), respectively (FSM1-20, FSM1-40, FSM1-60, FSM2-20, FSM2-40 and FSM2-60). Then the seven diets were fed to rainbow trout (18.1 g) for 8 weeks. Weight gain (WG), feed conversion ratio (FCR) and digestibility of crude protein and dry matter showed no significant difference among the groups of FSM1-20, FSM1-40, FSM2-20, FSM2-40 and the control, but WG significantly decreased and FCR increased when 60% FM was replaced by both FSMs (p