Growth performance, intestinal microbiota and immune response of grass carp fed isonitrogenous and isoenergetic diets containing faba bean extracts

Abstract Functionally active components of faba bean (Vicia faba, FB) are known to improve the muscle texture and growth performance of grass carp (Ctenopharyngodon idellus), but this has not yet been proven by feeding trials using isonitrogenous and isoenergetic diets. Here, we formulated isonitrogenous and isoenergetic diets containing four types of FB extracts and examined their effects on the weight gain, textural quality, intestinal microbiota, metabolic enzymes and immune response of grass carp by a 100-day feeding trial. An isonitrogenous and isoenergetic diet with no FB extracts (control) and whole FB were also used. Compared to the control, the FB water extract diet increased weight gain, muscle hardness and chewiness, intestinal microbiota diversity, the activity of metabolic enzymes including lipase (LP), glucose-6-phosphatase (G-6-P), acetyl-CoA and succinate dehydrogenase (SDH) (P