Effects of replacement of dietary cottonseed meal by distiller’s dried grains with solubles on growth performance, muscle texture, health and expression of muscle‐related genes in grass carp (Ctenopharyngodon idellus)

Both cottonseed meal (CSM) and dried distiller's grains with solubles (DDGS) are important plant protein sources for fish. This study investigated the effects of dietary DDGS inclusion to replace different portions of CSM on growth performance, muscle texture, health status as well as myogenic‐related genes expression of juvenile grass carp (initial weight: 5 g). A 60‐d feeding trial was performed by feeding fish with three isonitrogenous and isoenergetic diets containing different levels of DDGS (0, 10.3% and 20.6%). The highest growth and feed efficiency occurred at 20.6% DDGS dietary inclusion. Body condition factor, hepatosomatic index, serum ALT and AST as well as hepatic GSH and T‐SOD all showed a downward trend with increasing dietary inclusion of DDGS (p