Effects of glutamate supplementation on feed consumption, intestinal histology, growth performance, muscle mass, intestinal barrier, and antioxidant-immune genes in the juvenile giant freshwater prawn, Macrobrachium rosenbergii

Abstract

The aim of the study is to explore the effects of glutamate (Glu) supplementation on feed consumption, digestibility, intestinal histology, growth, gut barrier, and the antioxidant–immune-related genes during the juvenile stage of freshwater prawn ( Macrobrachium rosenbergii ). The supplementation of Glu at doses of 55 and 550 mg/kg feed significantly enhanced feed consumption, digestion, digestive enzyme activities, and gut histology ( P < 0.05). Feeds supplemented with these two doses of Glu improved growth, demonstrated by increased body size, weight gain (WG), growth rate (GR), specific growth rate (SGR), and average daily gain (ADG) during weeks 8–12 ( P < 0.05). Additionally, juvenile prawns fed diets supplemented with both doses of Glu exhibited significant upregulation of appetite-related gene, as well as muscle growth-related and immune-related genes ( P < 0.05). Survival rate (SR) was significantly higher for juvenile prawns receiving diets with Glu supplementation at weeks 8 and 12. Collectively, these results indicate that Glu function as an appetite stimulant, growth enhancer, and immune modulator; therefore, this neurotransmitter may be a potential food additive for improving the production of juvenile prawns raised in an aquaculture system.