Effect Of Astragalus Polysaccharide On Performance,Antioxidant,Lipid Metabolism And Intestinal Microorganism Of Fattening Pigs

Astragalus polysaccharide is an active ingredient of the Chinese medicine astragalus,which has various effects and improves body performance.Our group found that the addition of 0.05 %,0.10 % and 0.15 % of astragalus polysaccharide in the diet of fattening pigs can improve the production performance,immune performance and meat quality of fattening pigs,among which the addition of 0.15 % has the best effect,so we select the amount of Astragalus polysaccharide that has better effect on growth performance,meat quality and immunity of fattening pigs,the best amount of astragalus polysaccharide was added to investigate the effect of astragalus polysaccharide on antioxidant,lipid metabolism and intestinal flora of fattening pigs.24 three-breed cross fattening pigs with similar average body weight,namely Duroc♂ x(Landrace ♂ x Large Yorkshire ♀),were selected as the experiment animals,and were randomly divided into2 groups(G1 and G2)with 3 replicates per group and 4 pigs per replicate.G1 was fed a basal diet,and G2 was fed a basal diet +0.15 % astragalus polysaccharide.The results showed that:(1)The diet was supplemented with astragalus polysaccharides had no significant effects on growth performance and partial slaughter performance of fattening pigs.Compared with G1,flesh color brightness,drip loss,steaming loss and shear force were significantly decreased by 6.62 %、14.57%、18.58%、3.59 % and 22.11 %(P<0.05),respectively(P<0.05),cooking percentage,threonine,isoleucine and leucine which are essential amino acid and arginine which is flavor amino acid were all significantly increased by 3.92 %,6.25 %,6.66 %,5.00 % and 6.40 %,respectively(P<0.05).The contents of total amino acids,essential fatty acids,nonanal,hexanal,cycloheptanol and 2-pentylfuran,S-methyl N,N-diethyl dithiocarbamate were significantly higher than those of G1(P<0.05).TFA and MUFA contents were significantly increased by 16.02 %and 15.02 %,respectively(P<0.05).The contents of C16:0(palmitic acid),C22:0(eicosapentaenoic acid),C24:0(tetracanodic acid)and C20:5n3(eicosapentaenoic acid)were significantly higher than those of G1(P<0.05).(2)Compared with G1,SOD,GSH-Px,T-AOC and CAT of liver in G2 were significantly increased by 34.49 %,34.51 %,35.47 % and 40.15 %,respectively(P<0.05).The expression levels of main antioxidant enzymes SOD2 and HO-1 in muscle and GSH-Px m RNA in liver of G2 were significantly increased(P<0.05).The m RNA expression level of Recombinant Keap1 in liver was significantly downregulated(P<0.05).(3)The levels of TG and LDL in the liver of the G2 were significantly reduced by 23.53 % and 57.14 %(P<0.05),and the levels of LPL were significantly increased by61.92 %(P<0.05)respectively.The m RNA expression level of ACC,PPARα,SREBP-1C and PPARγ were significantly decreased(P<0.05).(4)The Chao1 index and Observed＿species index was significantly higher in the G2 compared to the G1(P<0.05).At the phylum level,the relative abundance of Cyanobacteria and Tenericutes was significantly higher in the G2 than in the G1(P<0.05).Among the top 10 genera at the genus level,the abundance of Bacteroides was significantly higher in G2 than in G1(P<0.05).The abundance of Lactobacillus was significantly higher in the G2(P<0.05).And after correlation analysis between the flora with LDAscore>3.5 and meat quality,liver antioxidant and lipid metabolism indexes,we found that muscle shear force,water loss rate,fatty acid content in muscle,activity of TG,SOD and LPL in liver were correlated with intestinal microorganisms.In conclusion,the diet was supplemented with astragalus polysaccharides can not only improve meat quality,nutritional value and flavor,improve liver antioxidant enzyme activity,activate Nrf2 antioxidant signaling pathway to improve the body’s antioxidant capacity and inhibit fat synthesis and deposition,significantly improved the abundance of cecum microflora and the relative abundance of beneficial bacteria,maintaining intestinal health and also provide some reference value for the subsequent application of astragalus polysaccharide in pig production.