LAUSR

Corn production in the US results in a variety of products, including ethanol and the recycling of coproducts into animal feed. Corn fermented protein (CFP) is a high‐protein, low‐fiber improved coproduct of the ethanol industry that is rich in lysine and methionine and doesn’t contain antinutritional factors. Because of these attributes, CFP is a potential candidate to replace soybean meal (SBM) whilst improving animal growth and health. Accordingly, the present work assesses the effects of CFP on channel catfish growth, whole‐body composition, overall health, and resistance to major disease‐causing bacteria. Six experimental diets were formulated to include CFP at 0%, 5%, 10%, 15%, 20%, and 30%. After feed preparation, 20 channel catfish fingerlings (2.56 ± 0.06 g) were randomly assigned to six replicate aquaria per diet. During the 70‐day experiment, catfish were weighed biweekly, and the feed ration was calculated as a percentage of the aquarium biomass and increased by 10% the following week. At termination, fish were group‐weighed, enumerated, then sampled for whole‐body proximate, serum lysozyme activity and biochemistry analyses. Subsequently, another set of catfish (5.29 ± 0.19 g) were acclimated to the diets for 42 days. Afterward, fish were challenged by immersion with Flavobacterium covae (1.00 × 10 6  CFU mL −1 ), virulent Aeromonas hydrophila (3.55 × 10 7  CFU mL −1 ), and Edwardsiella ictaluri (1.60 × 10 5  CFU mL −1 ). Results of the present work suggest that CFP can be successfully used at 30% of channel catfish diets. Fish growth, survival, protein retention, whole‐body proximate composition, serum lysozyme activity, or biochemistry were similar regardless of the CFP inclusion level ( p > 0.05). Additionally, CFP inclusion does not seem to confer protection against F. covae or virulent A. hydrophila infections but seems to change catfish survival postinfection with E. ictaluri . CFP can be successfully used as an ingredient in channel catfish diets, but the potential to protect the fish against bacterial infections needs further investigation.