Effects of Fishmeal Replacement by Enzymatically Hydrolyzed Corn Protein on Growth Performance and T-Cell Immune Regulation in Juvenile Yellow Catfish (pelteobagrus Fulvidraco).

Despite rapid expansion, the aquaculture industry faces the dual challenges of finite fishmeal resources and heightened disease susceptibility under intensive farming. To advance sustainability, plant proteins are being actively developed as fishmeal alternatives due to their lower cost. This study investigated the effects of replacing fishmeal with enzymatically hydrolyzed corn protein (EHCP) on intestinal digestion, absorption, and inflammatory response in juvenile yellow catfish (Pelteobagrus fulvidraco). The substitution of 6% EHCP enhanced the growth performance and intestinal function of juvenile yellow catfish. Following the Vibrio mimicus challenge, EHCP alleviated intestinal inflammation by promoting immune cell differentiation and suppressing pro-inflammatory cytokine expression. Mechanistically, EHCP promoted CD4+ T-cell differentiation into key effector subsets (Th1, Th2, Th17, and Treg) via JAK-STAT and NF-κB signaling pathways, thereby maintaining intestinal homeostasis. The optimal EHCP substitution levels (6.38 and 6.40%) provide an efficient and economically viable innovative solution for sustainable aquafeed development.