Effects of Dietary Wheat Gluten Meal on Growth, Intestinal Morphology, and Microbiome in Juvenile Large Yellow croaker Larimichthys crocea

Abstract

Wheat gluten meal (WGM) was evaluated as a replacement for fish meal (FM) for juvenile Larimichthys crocea．FM was replaced by 0%, 25%, 50%, 75%, and 100% of WGM (WGM0, WGM25, WGM50, WGM75, and WGM100, respectively). In addition, all diets except the control group were supplemented with amino acids. Fish were fed twice daily for 56 days. There were no significant differences in survival and feed conversion ratio (FCR) among all treatments (P>0.05). WGM25, WGM50, and WGM75 groups had significantly higher specific growth rate (SGR) and weight gain ratio (WGR) than those fed with WGM0 (P<0.05). There were no significant differences in mucosal thickness (MT), lamina propria width (LW), mucosal fold height (MH), and goblet cell quantity of single hair (GC) for all the diets (P>0.05). The indexes of Chao1, Shannon, Simpson, and Good coverage in fish fed with WGM0, WGM50, and WGM100 were not significantly affected (P>0.05). Firmicutes (81.03~94.03%) were the dominant bacterial community in juvenile large yellow croaker. Compared with the WGM0 group, the abundance of Firmicutes increased significantly, and Proteobacteria decreased significantly in the WGM100 group (P<0.05). These results suggested that WGM could replace 366.3 g kg-1 FM of the juvenile large yellow croaker diet.