Enhanced growth performance, immune responses, immune-related gene expression and disease resistance of red swamp crayfish (Procambarus clarkii) fed dietary glycyrrhizic acid

Abstract

Abstract Glycyrrhizic acid (GA) is an effective antiviral agent and is widely used in humans and animals. However, while the impact of disease on crustaceans is increasingly serious, research on the application of GA in crustaceans is very rare. The effects of GA on the growth performance, immune response, immune-related gene expression and disease resistance of crayfish were studied. A total of 900 healthy and equal weight crayfish were randomly divided into six groups for a feeding experiment, which lasted 60\xa0days: the GA25, GA50, GA75, GA100 and GA150 groups were fed a basal diet supplemented with 25, 50, 75, 100 and 150\xa0mg·kg−1 GA, respectively, and the control group was fed a basal diet. The results showed that the crayfish in the groups supplemented with 75 to 100\xa0mg·kg−1 GA had an increased final body weight (FBW), weight gain (WG) and specific growth rate (SGR) and decreased feed conversion ratio (FCR) compared with the controls (P