Macleaya cordata extract improves the growth performance and intestinal health of American eels (Anguilla rostrata) farmed in intensive system

The present study was conducted to evaluate the effects of dietary Macleaya cordata extract (MCE) supplementation on growth performance and intestinal health of American eels (Anguilla rostrata) farmed in intensive system. A total of six cement tanks of fish were randomly divided into a control group fed a commercial diet and an MCE group fed the commercial diet with 100 mg/kg MCE, respectively. There were three replicates in each group. The results suggested that 100 mg/kg MCE could improve the growth performance and intestinal health of the American eels by strengthening the barrier function and antioxidative ability in the intestine and beneficially modulating intestinal microbiota with the higher relative abundance and more species of the potential probiotics and the lower relative abundance of potentially pathogenic bacteria.