摘要The impacts of substituting dietary soybean meal(SBM)with yellow mealworm meal(YMM)were investigated during a 56-day feeding trial on growth,antioxidant capacity,immunity,intestinal morphology,and intestinal microbiota of grass carp.A total of 750 grass carp were divided into 5 groups(3 replications per group and 50 fish per replication)with different levels of YMM:SBM(control group),H25,H50,H75,and H100,for 8 weeks.The results showed that dietary YMM significantly increased final body weight(FW),weight gain(WG),and protein efficiency ratio(PER)in H25 group(P＜0.05);however,complete substitution showed the opposite trend(P＜0.05 for FW and WG).The liver antioxidant capacity was improved,manifested by enhanced superoxide dismutase(SOD),catalase(CAT),glutathione peroxi-dase(GPx)activities,glutathione(GSH)content and up-regulated antioxidant-related genes mediated by the Keap1-Nrf2 signaling pathway in the H25 group(P＜0.05).However,in the H100 group oxidative stress occurred in parallel with impairment of hepatic function.Intestinal inflammation was aggravated in the H100 group as evidenced by the up-regulated pro-inflammatory gene expression mediated by the NF-κB pathway(P＜0.05).Additionally,the activity of intestinal digestive enzymes for the grass carp was significantly reduced and accompanied with intestinal mucosal barrier dysfunction in the H100 group(P＜0.05).In summary,replacement of SBM with 25％YMM showed positive influences on growth,anti-oxidant capacity,immunity,and intestinal health.Conversely,complete replacement of SBM with YMM triggered oxidative stress,caused liver function disorder,and impaired intestinal health in grass carp.