摘要
This experiment aimed to discuss and reveal the effect and mechanism of mannanase on intestinal inflammation in broilers triggered by a soybean meal diet.In this experiment,384 Arbor Acres broilers at1 d old were randomly divided into 3 treatment groups.The broilers were fed a corn-soybean meal basal diet,a low-energy diet(metabolizable energy reduced by 50 kcal/kg),and a low-energy diet supplemented with 100 mg/kg mannanase for 42 d.The low-energy diet increased feed conversion ratio from0 to 42 d,reduced ileal villus height and villus height-to-crypt depth ratio and upregulated the expression of nuclear factor kappa B(NF-κB)in the ileum(P<0.05).It also reduced cecal short-chain fatty acids(SCFA),such as acetic acid(P<0.05).Compared with low-energy diets,the addition of mannanase increased body weight at 42 d,promoted the digestibility of nutrients,and maintained the morphology and integrity of the intestinal epithelium of broilers(P<0.05).In addition,mannanase upregulated the expression of claudin-1(CLDN1)and zonula occludens-1(ZO-1)in the jejunum at 21 d,downregulated the expression of ileal NF-κB,and increased the content of isobutyric acid in the cecum of broilers(P<0.05).The results for the ileal microbiota showed that a low-energy diet led to a decrease in the relative abundance of Lactobacillus reuteri in the ileum of broilers.The addition of mannanase increased the relative abundance of Lactobacillus-KC45b and Lactobacillus johnsonii in broilers.Furthermore,a low-energy diet reduced the relative abundance of Butyricicoccus in the intestine of broilers and inhibited oxidative phosphorylation and phosphoinositol metabolism.Mannanase increased the relative abundance of Odoribacter,promoted energy metabolism and N-glycan biosynthesis,and increased the activities of GH3 and GH18.It is concluded that mannanase could improve the growth performance of broilers by reducing the expression of NF-κB in the ileum,increasing the production of SCFA in the cecum,suppressing intestinal inflammation,balancing the intes
基金
financially supported by the China Agriculture Research System Program(CARS-41-G11)
