Utilization of soybean meal as an alternative protein source in the Mediterranean yellowtail, Seriola dumerili

Abstract

The availability of defatted soybean meal as a substitute for
\nfish meal was evaluated in juvenile (450 g on average) yellowtail fed diets containing several levels of soybean meal
\n(from 20 to 50%). After 153 days, liveweight averages were
\n980, 925, 795 and 670 g for fish fed diets in which fish meal
\nwas partially substituted with 20, 30, 40 and 50% soybean
\nmeal, and feed conversion ratios were 2.79, 3.09, 4.57 and
\n6.52, respectively. Regression analysis showed a negative
\neffect of inclusion of soybean, although fish fed diets containing 20% and 30% of soybean did not present statistical
\ndifferences and grew significantly more, and had a better feed
\nconversion ratio, than fish fed 40 or 50% diets. Likewise,
\nmuscle protein level was lower and lipid content was higher
\nin fish fed 20 or 30% soybean. No differences were obtained
\nfor protein digestibility coefficients of experimental diets.