Effects Of Different Irons On Iron Metabolism,intestinalmucosal Immunity And Ileum Fiora Structure In Sucking Piglets

Iron is an important immune nutrient in animals and plays an important role in maintaining the intestinal health of animals.The common iron sources in pig feed include ferrous sulfate,ferrous lactate,ferrous glycine,and iron yeast,etc.The biological effects of different iron sources are different.In this study,2 days of age iron deficiency suckling piglets are used to investigate the effect of different source of iron（iron source:Fe SO₄,organic and inorganic iron source:Fe Gly and Febis Gly）on growth performance,blood biochemical,intestinal morphology,intestinal iron absorbing and mucosal immune function and influence of gut microbes.This study explored the mechanisms of different iron sources affecting the intestinal health of young animals from the perspectives of morphology,microbiology and molecular biology.The main results are as follows:1. The effects of different iron sources on growth performance and iron absorption and metabolism of suckling pigletsIron supplementation significantly increased HGB,MCV and MCH in suckling piglets（P<0.05）,significantly decreased MCHC（P<0.05）,increased the content of iron in the kidney and liver of piglets（P<0.05）,and significantly increased the gene expression of DMT1,HIF-2a,Ferritin-h and Ferritin-l in duodenum（P<0.05）.Injection of iron and feed administration of organic iron（Fe Gly and Febis Gly）significantly increased the average daily weight gain of piglets at 15-21d（P<0.05）,and the relative expression levels of Ferritin-h and Ferritin-l were significantly up-regulated by supplementation of organic iron（Fe Gly and Febis Gly）（P<0.05）.2. The effects of different iron sources on intestinal mucosal immunity of Suckling pigletsIron supplementation significantly increased the weight of small intestine（P<0.05）,significantly increased the villus height and crypt depth of jejunum in suckling piglets（P<0.05）,significantly up-regulated the relative expression of ZO-1 in jejunum（P<0.05）,and Occludin in ileum（P<0.05）.Supplementation of Febis Gly significantly up-regulated the expression of Claudin and ZO-1 genes in jejunum（P<0.05）,as well as the relative expression of MUC1,MUC2 and MUC4 in jejunum（P<0.05）and the expression of MUC2 in ileum（P<0.05）,and improved intestinal mucous secretion and intestinal mucosal immune function.Feed iron supplementation significantly increased the expression levels of PBD1and PBD3 m RNA in jejunum（P<0.05）.Febis Gly supplementation significantly up-regulated the expression of IL-10 and TNF-αm RNA in jejunum（P<0.05）,and significantly increased the expression of PBD2 m RNA in jejunum and ileum（P<0.05）.3. The effects of different iron sources on ileum flora structureIron supplementation has no significant effect on Chao1,Shannon and Simpson index（P>0.05）,and Fe SO₄ significantly improves the Ace index compared with the Fe De X group（P<0.05）.As can be seen from the PCA,the composition of each group is different.At the phylum level,feed administration of inorganic iron（Fe SO₄）and organic compound iron（Fe Gly and Febis Gly）significantly reduced Acidobacteria and Gemmatimonadetes in ileum（P<0.05）.Compared with the Fe Gly group,Febis Gly significantly decreased the relative abundance of Proteobacteria（P<0.05）.At the family level,compared with the NON group,Fe Gly significantly increased the relative abundance of Enterobacteriaceae in the ileum（P<0.01）.Intramuscular injection Fe De X significantly increased the relative abundance of Gemmatimonadaceae and Sphingomonadaceae（P<0.05）.At the genus level,iron supplementation significantly reduced Blautia in ileum（P<0.05）.Feed administration of Fe SO₄ can significantly improve Anaerotipes and Faecalibacterium（P<0.05）.Compared with intramuscular iron injection and inorganic iron administration,Febis Gly administration significantly improved Roseburia in ileum（P<0.05）.Lactobacillus was reduced by 34%,34%and44%by addition of Fe De X,Fe Gly and Febis Gly compared with NON.Correlation analysis showed that Ferritin-l,Ferritin-h and HIF-2αgenes in iron metabolism were positively correlated with Anaerostipes,Faecalibacterium,[Ruminococcus]＿gnavus＿group in ileum（P<0.05）.Claudin and PBD1 were positively correlated with Anaerostipes,Faecalibacterium,Megamonas and[Ruminococcus]＿gnavus＿group in jejunum（P<0.05）.MUC2 was positively correlatedwithErysipelotrichaceae-UCG-003,Megamonasand[Eubacterium]＿hallii＿group（P<0.05）.IFN-γgene was positively correlated with Sphingomonas relative abundance in the ileum（P<0.05）.There was a weak negative correlation between IL-6 and Megamonas relative abundance in ileum（P<0.05）.In conclusion,piglets significantly improved iron status and intestinal morphology after iron supplementation.Febis Gly supplementation promoted the expression of goblet cell mucin（MUC1,MUC2 and MUC4）,intestinal antimicrobial peptides（PBD2and PBD3）and tightly linked proteins（ZO-1 and Claudin）,and improved the intestinal mucosal immune function of piglets.Administration of glycine complex iron can significantly improve the microbial diversity of ileum,increase the quantity of Faecalibacterium,Enterobacteriaceae and Roseburia,and reduce the quantity of Lactobacillus.