Effects Of Dandelion On Growth Performance,Nutrients Digestion And Intestinal Barrier Function Of Broilers

The intestinal barrier function plays an important role in improving digestion and absorption and maintaining health of broilers.Dandelion is rich in active substances such as polysaccharides,polyphenols,flavonoids and terpenes.With functions of antibacterial,immune regulation and gastrointestinal protection,it has great potential to become a green additive instead of antibiotics.Therefore,the purpose of this experiment was to study the effects of dandelion on growth performance,nutrient digestion and intestinal barrier function of broilers.One-hundred and sixty 1-day-old Arbor Acres(AA)male broilers were randomly divided into four groups,with five replicates of eight birds each.The birds were fed a basal diet supplemented without(control group,[CON])or with 500(low dose[LD])or 1000(high dose [HD])mg/kg dandelion or with 50 mg/kg chlortetracycline(CTC)for 42 days,including the starter phase(d 1 to 21)and the grower phase(d 22 to 42).The following main results were obtained:1.Compared to CON group,the LD group decreased the average daily food intake(ADFI)and feed consumption to weight ratio(F/G)in 1～21 d(P<0.05),decreased F/G in1～42 d(P<0.05),increased the trypsin(Try)activity in the ileum at 21 days old(P<0.05),and increased the activity of α-Amylase(α-Amy)in duodenum and lipase(Lip)in ileum at 42 days old(P<0.05).Compared to CON group,the HD group decreased F/G in 1～42 d(P<0.05),increased the activity of α-Amy and Lip in duodenum,Lip in jejunum and α-Amy,Lip and Try in ileum at 21 days old(P<0.05),increased apparent metabolic rates of dry matter(DM)and organic matter(OM),the activity of α-Amy in duodenum,Lip and chymotrypsin(Chy)in jejunum and α-Amy and Lip in ileum at 42 days old(P<0.05).2.Compared to CON group,at 21 days old,the LD group increased the gene expression of Claudin,Occludin-1,and mucin-1(MUC1)in ileum(P<0.05),the HD group increased the gene expression of Claudin,Occludin-1,zonula occluden-1(ZO-1),and MUC1 in ileum(P<0.05),the LD and HD group increased the relative abundance of Firmicutes and Lactobacillus at the level of phyla and genera and decreased the relative abundance of Bacteroidata and Bacteroides at the level of phyla and genera in ileum(P <0.05).At 42 days old,the LD group decreased the content of D(-)-lactic acid(D-LA)in serum,and increased the gene expression of Claudin,Occludin-1,and MUC1 in ileum(P<0.05),the HD group decreased the content of D-LA and lipopolysaccharide(LPS)in serum,and increased the gene expression of ZO-1 in ileum(P<0.05).In conclusion,dandelion improved the apparent digestibility of nutrients and the activity of digestive enzymes,enhanced the intestinal barrier function,reduced the intestinal permeability,and finally promoted the growth performance of broilers.