Comparative evaluation of soybean meal and carob seed germ meal as dietary ingredients for rainbow trout fingerlings

Abstract

Carob seed gcrm meal (CSGM), and soybean meal (SBM), were tested as ingrcdients of diets for rainbow trout (Oncorhynchus mykiss) fingerlings at three lcvcls of inclusion, contributing 20 to 50% of the total protein of the diet. Fish growth decreased as the level of the plant by-product in the diet increased. Diets containing CSGM resulted in lowcr growth than comparable SBM diets, especially at inclusion levels contributing 37 and 53% of the total protein. High dietary CSGM levels decreased body protein and increased liver protcin indicating possible amino acid dcfiçiencies and/or imbalances at high inclusion levels. Mortality was also high at the high dietary CSGM Icvel. The results are discussed with referencc to the antinutritional factors contained in the raw materials tested and their possible effects on protein availability.