Evaluation of Soybean Meal as a Partial Substitute for Fish Meal in Formulated Diets for Korean Rockfish, Sebastes schlegeli

This study was designed to determine the level of soybean meal (SM) that could be substituted for fish meal in the diet for Korean rockfish (Sebastes schlegeli). A control diet with white fish meal as only protein source was included, SM was substituted at levels of for portions of the fish meal in the diet. Amino acids (met+lys) supplementation and two different SM particle sizes (0.5 mm and 0.25 mm) in the SM diet were compared. In addition, combination of SM, corn gluten meal (CGM) and meat and bone meal (MBM) was substituted for the fish meal in the diet. Duplicate groups of the 30 fish averaging 22.9 g were fed one of 8 isoproteic and isolipidic experimental diets to satiation twice a day for 9 weeks. No significant differences were found among fish fed the control, substituting up to SM containing amino acids, and MBM diets in weight gain, feed efficiency, daily feed intake, and protein retention (P>0.05). Feed efficiency, daily feed intake and protein retention in fish fed the diet containing SM with 0.5 mm particle size were not significantly different to those in fish fed the diets containing less than $20\%\;SM\;(P>0.05)$, however, weight gain was significantly lower than that of the control and $5\%\;SM\;diets\;(P in the diet, and that the inclusion of SM with an adequate combination of several protein sources can replace larger amounts of fish meal in the diet.