The objective of this research study was to optimize soybean meal (SBM) levels in diets for pond-raised hybrid catfish (Channel Catfish Ictalurus punctatus×Blue Catfish I. furcatus).   Five 28% protein diets containing 15, 20, 25, 30 and 40% SBM were formulated with digestible nutrients and energy levels to meet or exceed all known nutrient requirements of Channel Catfish.  Fingerling hybrid catfish with an average weight of about 25g were stocked into 25 earthen ponds.  The fish were fed once daily for the 184 day growing season.

Results indicated that increasing the levels of SBM in the basal diet from 15 to 40% did not significantly affect total amount of diet fed, gross yield, weight gain, and survival of hybrid catfish. The feed conversion ratio was significantly higher in fish fed diets containing ≤30% soybean meal than those fed the 40% soybean meal diet and feed conversion ratio decreased linearly as soybean meal levels increased.   Regression analyses show that both carcass and fillet yields increased linearly with increasing soybean meal levels in the diet.   No significant differences were observed for fillet protein, fat, and moisture levels among fish fed the diets containing various levels of soybean meal.   The research group concluded that a 28% protein diet containing 25% soybean meal appears to support maximum growth of hybrid catfish without marked impact on feed conversion ratio or processed yield.