Effects of Dietary Pediococcus acidilactici and Isomaltooligosaccharide on Growth Performance, Immunity, and Antioxidant Defense in Juvenile Common Carp

The aim of this study was to investigate the synbiotic effects of Pediococcus acidilactici (PA) and isomaltooligosaccharide (IMO) on the performance of juvenile common carp (Cyprinus carpio). A total of 360 fish ( $17.22\pm 0.19$ g) were randomly divided into six groups with three replicates of 20 fish each. The trial continued for 8 weeks. The control group was fed only basal diet; PA was fed basal diet supplemented with 1 g/kg (1010 CFU/kg) PA, IMO5 (5 g/kg IMO), IMO10 (10 g/kg IMO), PA-IMO5 (1 g/kg PA and 5 g/kg IMO), and PA-IMO10 (1 g/kg PA and 10 g/kg IMO). The results indicated that the diet containing 1 g/kg PA and 5 g/kg IMO significantly increased the fish growth performance and decreased the feed conversion ratio ( $p<0.05$ ). Overall, blood biochemical parameters, serum (lysozyme, complements C3 and C4) and mucosal (protein, total immunoglobulin, and lysozyme) immune responses, and antioxidant defense of fish also improved in the PA-IMO5 group ( $p<0.05$ ). Therefore, a combination of 1 g/kg (1010 CFU/kg) PA and 5 g/kg IMO can be recommended as a beneficial synbiotic additive and immunostimulant in juvenile common carp.