Evaluation of Low‐protein Alternative Diets for Pond‐raised Hybrid Catfish, Ictalurus Punctatus × Ictalurus Furcatus

A study was conducted to evaluate low-protein traditional or alternative diets for pond-raised hybrid catfish, Ictalurus punctatusxIctalurus furcatus. Three 24% protein diets containing decreasing levels of soybean meal (30, 20, and 15%) and increasing levels of cottonseed meal and corn germ meal were compared with a 28% protein control diet. Hybrid catfish fingerlings (mean initial weight=71g/fish) were stocked into 20 earthen ponds (0.04ha) at a density of 14,826 fish/ha with five ponds per dietary treatment. Fish were fed once daily to apparent satiation for a 191-d growing season. There were no significant differences in total diet fed, net yield, weight gain, feed conversion ratio (FCR), survival, or fillet proximate nutrient composition among dietary treatments (P0.10). However, regression analysis showed for fish fed 24% protein diets there was a linear increase in FCR as soybean meal levels decreased (P=0.06). Compared with fish fed the 28% protein control diet, fish fed 24% protein diets had lower carcass and fillet yield. Results demonstrate a 24% protein alternative diet containing 20% soybean meal may be substituted for 28% protein diets for hybrid catfish during food fish production.