LAUSR

Abstract Commercial channel catfish (Ictalurus punctatus) is an economically valuable agricultural commodity in the United States, which suffers heavily from bacterial pathogens including Edwardsiella ictaluri. Our previous study revealed that dietary trans-cinnamaldehyde (TC) reduces catfish mortality after E. ictaluri infection, but there is limited knowledge of the effect of TC on the antioxidant defense system in catfish. In this study, we aimed to investigate the response of the catfish antioxidant defense system following TC feeding as well as E. ictaluri infection. In the first experiment, catfish fingerlings were fed with a basal diet or a basal diet supplemented with TC (20 mg/kg diet) for 10 days, and the level of five oxidative stress biomarkers were measured in the hepatic tissue. Compared with the control group, superoxide dismutase (SOD) activity was increased significantly and the malondialdehyde (MDA) concentration decreased significantly (P