Effects Of Puerarin On Growth Performance And Intestinal Barrier Function Of Broilers Fed With Oxidized Soybean Oil

Lipids are important high-density energy source to improve the metabolizable energy of poultry dietary.High in content of unsaturated fatty acids(USFAs)in vegetable oil which will be prone to oxidative rancidity with the generation of lipid peroxides..Oxidized fats in diets can cause oxidative stress of livestock and poultry through a variety of ways,leading to decreased antioxidant function and immunity,intestinal inflammation and damage of structure and function,resulting in decreased production performance.Puerarin belongs to flavonoids,which has the abilities of anti-inflammatory,anti-apoptotic,scavenging free radicals and anti-oxidation.This study was conducted to investigate the effects of puerarin on growth performance,antioxidant capacity,immune function,intestinal morphology and structure,intestinal microflora,and innate immune-related gene expression in broilers fed oxidized soybean oil,and to preliminary clarify the mechanism of puerarin on growth performance and intestinal barrier function of broilers fed oxidized soybean oil.A 2×2 factor design was used in which included oil quality(fresh soybean oil and oxidized soybean oil)and puerarin supplemental level(0 and 750mg/kg).A total of 360one-day-old healthy female yellow-feathered broilers were randomly divided into 4treatment groups with 6 replicates per group and 15 broilers per replicate,which were fresh soybean oil diet group,fresh soybean oil + puerarin(750mg/kg)diet group,oxidized soybean oil diet group and oxidized soybean oil + puerarin(750mg/kg)diet group.Samples were collected at 28 and 56 days of age and their growth performance was calculated.Serum biochemical indices were determined.The intestinal morphological structure and microbial species and diversity of ileum contents were analyzed.The intestinal mucosal antioxidant indexes,the m RNA expression levels of innate immune related genes and the protein expression levels of MAPKs/NF-κB were determined.The results are as follows:1.Feeding oxidized soybean oil significantly increased feed to gain ratio and serum CORT content of 28-56 day-old yellow-feathered broilers(P<0.05),and significantly decreased the activities of GSH and SOD in serum(P<0.05).Dietary supplementation of puerarin significantly increased the average daily feed intake of yellow-feathered broilers at 28 to 56 days of age and 1 to 56 days of age(P<0.05),significantly decreased the serum CORT content and significantly increased the serum IL-10 content of yellow-feathered broilers fed oxidized soybean oil(P<0.05).2.The intestinal mucosal morphological structure was damaged by feeding oxidized soybean oil,and the m RNA expression of tight junction protein Claudin-1 was decreased(P<0.05),Significantly decreased the contents of GSH,SOD and T-AOC content in ileum at 28 days of age and GSH and SOD content in ileum at 56 days of age(P<0.05).Adding puerarin increased the m RNA expression of tight junction protein Zo-1 in small intestine mucosa of broilers(P<0.05),and significantly increased the activities of GSH in ileum of broilers at 28 days of age,CAT and SOD in duodenum,GSH and SOD in ileum at 56 days of age of broilers(P<0.05).3.Feeding oxidized soybean oil changed the number of microbial-specific OTUs and the number of flora species in ileal contents,and significantly increased Shannon and Simpson indexes of ileal contents at 28 days of age,and phylum level Bacteroidetes,Synergistetes and genus level Ruminococcaceae＿UCG-014 at 56 days of age(P<0.05).Feeding oxidized soybean oil changed the structure and species abundance of intestinal microflora and caused microbial dysfunction.Dietary supplementation of puerarin decreased the number of microbial-specific OTU in ileal contents at 56 days of age.4.Feeding oxidized soybean oil significantly increased the m RNA expression levels of HSP70,HSP90,TNF-α in jejunum and IRAK4 in ileum at 28 days of age,HMGB1,My D88,SIg IRR,SOCS-1 and IL-6 in duodenum and the m RNA expression levels of My D88,TNF-α in jejunum and HSP70,TLR2,TLR4,TLR15,IL-6,IL-12 B and TGF-β1 in ileum at 56 days of age(P<0.05);Significantly decreased the m RNA expression levels of SIGIRR,CATH-1 and CATH-B1 in ileum at 28 days of age(P<0.05),and significantly increased the protein expressions of TLR4,p-p38 /P38,p-ERK/ERK,p-p65 /P65 in jejunum,p-JNK/JNK and p-p65 /P65 in ileum at 56 days of age(P<0.05).Dietary supplementation of puerarin significantly increased the m RNA expression levels of TLR4,My D88,A20,SOCS-1,Tollip,IL-10 and TGF-β1 in jejunum of broilers at 28 days of age(P<0.05);Significantly decreased the m RNA expression levels of duodenal SIGIRR and ileum TNF-α at 28 days of age and HSP90 and IL-12 A in ileum at 56 days of age(P<0.05);Significantly increased m RNA expression level of CATH-1 in jejunum mucosa at 56 days of age(P<0.05).In conclusion,Feeding oxidized soybean oil decreased feed conversion ratio,increased serum corticosterone content and decreased serum antioxidant capacity,which caused oxidative stress,destroyed intestinal mucosal morphology,decreased the expression of tight junction protein gene,changed intestinal flora structure and species abundance,activated MAPKs and NF-κB signaling pathway,and caused mucosal injury.Dietary supplementation of puerarin inhibited its change and partially alleviated the adverse effects of oxidized soybean oil on mucosal barrier function of broilers.