Growth, feed utilization, health and organoleptic characteristics of European seabass (Dicentrarchus labrax) fed extruded diets including low and high levels of three different legumes

Three legumes [field peas (P), chickpeas (CP) and faba beans (B)] were evaluated at two inclusion levels; 170 (L) and 350 g kg− 1 (H) in a 14-week experiment with triplicate groups of 97.9 ± 6.1 g European seabass. A control diet included wheat meal, fish meal (FM) and a mixture of plant ingredients as protein sources. Diets, processed in a twin-screw extruder, were isonitrogenous and isoenergetic. All experimental diets improved growth compared to the control. Weight gain, feed intake, FCR and SGR were improved for fish fed diet CPL, while fish fed diet CPH gave higher FCR. Protein and starch digestibility were highest for the control diet, while fish fed diets CPL and PL showed significantly lower protein ADCs and lower starch ADC (P ≤ 0.05) for diet PH. Among H diets, significantly better fillet yield was found for fish fed diet PH, but no other differences were found in seabass fillet organoleptic characteristics. Serum glucose and cholesterol were elevated in fish fed CP diets, while protein and triacylglycerols did not show significant differences among treatments. Fish fed the test diets showed no significant evidence of either immunosuppression or immunostimulation. Histology of liver, spleen, kidney and foregut revealed no pathological abnormalities. Field peas, chickpeas and faba beans can be included in European seabass diets up to 350 g kg− 1 substituting for wheat with no negative effects on growth performance, carcass composition or organoleptic characteristics.