Cobia Cage Study

An eight-week feeding experiment conducted in (1.5x1.0x2.0m) floating cages was conducted to determine the potential use of defatted soybean meal as a partial replacement of fishmeal for juvenile cobia initially weighing about 8.3g. An isonitrogenous diet containing about 45 percent protein was formulated with 0-60 percent of the fishmeal replaced with a solvent-extracted soybean meal. The results of the study indicated that up to forty-percent of the fishmeal could be replaced with soybean meal with out causing a significant reduction in fish growth. The lowest feed conversion ratio and highest protein efficiency ration occurred when twenty-percent of the fish meal was replaced with soybean meal. They reported no significant differences in the moisture, lipid, crude protein and ash content of the whole body and muscle, while the lipid content of the live increased as the dietary protein content of the diet increased. These researchers concluded that the optimum level of fishmeal, based on quadratic regression analysis of the weight gain was 18.9 percent replacement.

Zhou, Q.C. and co-workers. 2005. Partial replacement of fishmeal by soybean meal in diets for juvenile cobia (Rachycentron canadum). Aquaculture Nutr. 11(3): 175-182.