Effects of Lactobacillus plantarum 15-1 and fructooligosaccharide on the response of broilers to pathogenic Escherichia coli O78 challenge

Abstract

One-day-old broilers were randomly allocated to 5 treatments: basal diet challenged by saline (negative control, n-control); basal diet and challenged by E.coil O78 (positive control, p-control); supplementation with L. plantarum 15-1 at 1x108 CFU/kg challenged with E.coil O78 (LP); supplementation with FOS at 5 g/kg challenged with E.coil O78 (FOS); supplementation with L. plantarum 15-1 and FOS challenged with E.coil O78 (LP+FOS). L. plantarum 15-1 or FOS had a lowered effect (P<0.05) on crypt depth on d 14 compared with two controls, and L. plantarum 15-1, FOS and L. plantarum 15-1+FOS also reduced relative to p-control on d 21. L. plantarum 15-1 reduced the level of diamine oxidase (DAO) at d 14 and 21 compared with p-control (P<0.05), the broilers with L. plantarum 15-1 and FOS increased the concentration of IgA and IgG relative to two control, and decreased diamine oxidase (DAO) compared with p-control (P 0.05). L. plantarum 15-1 increased the concentration of acetic acid and total short-chain fatty acid (SCFA) in comparison with p-control at d 14 (P<0.05), FOS improved the level of valeric acid and total SCFA relative to p-control at d 21 (P<0.001), the broilers fed L. plantarum 15-1 and FOS were increased the level of butyric acid at d 14 (P<0.05). FOS enhanced bursal index of broilers at d 21 (P<0.05). L. plantarum 15-1 and FOS did no effect on the growth performance. In conclusion, FOS can promote average daily gain, L. plantarum 15-1 and FOS can improve intestinal morphology, and increase the concentration of SCFA in cecal contents in broilers challenged with E.coil O78. These results suggest that L. plantarum 15-1 and FOS have effective mitigation to E. coil O78 via lowing reducing the intestinal injury and enhancing the immune responses.