Abstract
Fingerling yellowtail Seriola quinqueradiata were fed fish meal-based moist pellet diets containing 0-30% commercial full-fat soybean meal (FFSB) in 0.8 ton aquaria for 30 days. Higher inclusions of FFSB slightly decreased protein and carbohydrate digestibilities and hemoglobin concentration. However, fish fed diets containing less than 30% FFSB resulted in a comparable growth rate, feed utilization efficiency, and body composition to those of fish fed a FFSB-free control diet. Extruding the FFSB-containing diet markedly improved growth performance and hematological characteristics in despite of unaltered amino acid composition, trypsin inhibitor activity, and antigen content in the diet. No improvement was observed when only FFSB in the diet was extruded or heated. These results suggest that FFSB is a potential alternative protein source, and extrusion of diet improves its nutritive value.
