Combined effects of emodin and Clostridium butyricum on growth and non-specific immunity of giant freshwater prawns, Macrobrachium rosenbergii

Abstract This study was conducted to evaluate the individual and combined effects of emodin and Clostridium butyricum on growth and non-specific immunity of giant freshwater prawn (Macrobrachium rosenbergii) for eight weeks with the initial body weight of 0.19 ± 0.5 g. Nine trial diets were prepared to contain three emodin levels (0, 25 and 50 mg/kg) and three C. butyricum levels (0, 250 and 500 mg/kg, 2 × 107 CFU/g) following a 3 × 3 factorial design. The diets were named as 0/0, 250/0, 500/0, 0/25, 250/25, 500/25, 0/50, 250/50 and 500/50 (C. butyricum/emodin), respectively. The results showed an interactive effect on the weight gain (WG) and feed conversion ratio were observed in prawns fed a diet containing 250 mg/kg C. butyricum and 50 mg/kg emodin, respectively. Besides, WG and specific growth rate (SGR) of prawns fed 250 mg/kg C. butyricum were both significantly (P