Evaluation of extruded chickpea, common bean and red lentil meals as protein source in diets for juvenile rainbow trout (Oncorhynchus mykiss).

An experiment was conducted to evaluate, the use of extruded chickpea, common bean and red lentil meals as dietary protein source for juvenile rainbow trout. Three experimental diets were formulated based on a reference diet, which composed of 70% reference diet and 30% test ingredient. The diets were given as triplicate groups of juvenile rainbow trout (initial weight of 50 g) to apparent satiation twice daily. There were no significant differences among the groups fed chickpea, common bean and reference diet, for weight gain, specific growth rate and feed conversion ratio, but there were significant differences among these groups and red lentil group in these respects. There were no significant differences in digestibility of protein between the fish fed chickpea and reference diets and chickpea and common bean diets, but the red lentil diet gave lower protein digestibility. Apparent protein digestibility coefficients of the ingredients were determined high for extruded chickpea (80.65%), mid-range for extruded common bean (72.91%) and low for extruded red lentil meals (50.07%). The results indicated that extruded chickpea and common bean meals have higher potential than red lentil meal for use as dietary protein source in diets for juvenile rainbow trout.