Nutritional value of whole cereal meals for European sea bass (Dicentrarchus labrax) juveniles

Abstract

The nutritional value of whole wheat, corn, rye and barley was evaluated for European sea bass. Four isoproteic and isolipidic diets containg 30% of each whole cereal meal were formulated. A growth trial and a digestibility trial were conducted and fish performance was evaluated in terms of growth, feed intake, feed utilization, macronutrients digestibility, liver composition, glycaemia and cholesterolemia levels and gut histomorphology.Growth and feed utilization ranged from 1.43 to 1.46 and from 0.55 to 0.58, respectively, and were similar among experimental groups. Whole body and liver composition, hepatosomatic and visceral indexes were also not affected by dietary composition. Corn diet revealed the lower dry matter (62.9) and starch (55.5) apparent digestibility coefficients. Protein digestibility in fish fed the rye diet was the lowest of all groups (91.3) and differed from that of wheat diet group (93.2), which might be due to antinutritional factors present in this feedstuff. Plasmatic glucose levels suggested a slower absorption rate in fish fed barley and corn diets. No signs of enteropathy related to the whole cereal meals were observed. Among cereals tested, rye seemed to be the less tolerated by sea bass, although all diets were well accepted and sea bass performed equally well with all diets.