Effects of Replacing Fish Meal in Diets on Growth and Body Composition of Palmetto Bass (Morone saxatilis × M. chrysops) Raised in Cages

ABSTRACT

Juvenile palmetto bass (Morone saxatilis X M. chrysops) with an average weight of 20 g were stocked into 12 floating cages (1.2 × 1.2 × 2.4 m) and fed one of four practical diets formulated to contain various percentages (0,15, 30, or 45%) offish meal (FM). Diets were formulated to be isonitrogenous (43% protein) and isocaloric (3.9 kcal available energy/g). Fish were fed twice daily, all they would consume in 40 minutes (0900 and 1730), for 125 days. Final individual weight and specific growth rate (SGR) of fish fed diets containing 15, 30, or 45% fish meal were not significantly different (P > 0.05) and averaged 342 g and 2.3%/day, while growth of palmetto bass fed a diet containing soybean meal (SBM), and meat-and-bone meal, without FM, was significantly (P <0.05) lower (282 g and 2.1%/day). There were no significant differences (P >0.05) in percentage moisture, protein, and lipid in fillet from palmetto bass in the four treatments, of which these values averaged 75.1%, 80.7%, and 14.5%, respectively. Amino acid composition of fillets was similar among treatments. These data suggest that a diet containing 15% FM is sufficient for diet palatabiiity and good growth in juvenile palmetto bass. Additional research on diet formulations without FM should be conducted.