Effects Of Polysaccharides On Immunity Functions And Their Mechanisms In Early-weaned Piglets

Effects of polysaccharides on the mechanisms and function of growth andimmunity in early-weaned piglets were discussed in the experiment. According tosingle factorial design, the experiment lasted 14 days. 25 healthy Duroc×Landrace×Yorkshire piglets (5.30±0.25kg BW) at 21 day of age were randomly divided into 5groups with 5 replicates of 1 piglet including:(1) Control group fed by basal diet (CR);(2) Treatment 1 fed with basal diet supplemented with 0.3% pure polysaccharides ofAtractylodes macrocephala koidz(PPAM); (3) Treatment 2 fed by basal dietsupplemented with 0.6% crude compound polysaccharides(CCP); (4) Treatment 3 fedby basal diet supplemented with 0.6% crude polysaccharides of atractylodesmacrocephala koidz(CPAM); (5) Treatment 4 fed by basal diet supplemented withantibiotic(15% chlortetracycline 150mg/kg and 4% flavomycin 50mg/kg)(ANT). Theresults showed as follows:1. Effects of polysaccharides on growth performance, serum biochemical indicesand plasma concentrations of hormone in early-weaned piglets(1)In the all trial, all treatments had no effect on ADFI(P＞0.05). between 0d and7d,ADG was higher in PPAM-supplemented piglets and CCP-supplemented piglets(P＜0.05), F/G was lower in PPAM-supplemented piglets,CPAM-supplemented andCP-supplemented piglets(P＜0.05);The ADG of PPAM was increased significantly(P＜0.05), while the F/G was decreased significantly (P＜0.05) between 7 d and 14d.Dietary supplementation with PPAM, CPAM and CCP improved ADG, and reducedF/G. (P＜0.05). (2) In contrast to CR, PPAM decreased serum level of BUN, AST andALT(P＜0.05); In contrast to ANT, serum level of glucose was low inCPAM-supplemented and CCP-supplemented piglets(P＜0.05), the rest of serumbiochemical indices(LAC,ALB,GLO,ALP,Tp.) did not differ amongtreatments;(3)The supplementation of PPAM and CCP enhanced the content ofT3(P＜0.05), addition of CP decreased the concentration of Cor (P＜0.05)and improvedthe level of INS (P＜0.05). PPAM,CCP and CPAM could increase the content of Gasand GH,but not significantly(P＞0.05). Serum and liver concentrations of cAMP onPPAM and CP were higher than those of CR(P＜0.05), the supplement of cPAMincreased serum level of cAMP in liver(P＜0.05). 2. Effects of polysaccharides on intestinal microflora and mucosal morphology ofearly-weaned piglets(1)In caecum, PPAM,CPAM and CCP were shown to increase the populations ofbifidobacteria(P＜0.01), while addition of PPAM had greater effect than CPAM,CCP(P＜0.05).Lactobacilli numbers were increased After feeding PPAM(P＜0.05) andCCP (P＜0.05); In colon, PPAM,CPAM and CCP were shown to increase numbers oflactobacilli (P＜0.01), numbers of bifidobacteria were increased by feedingPPAM(P＜0.01) and CP(P＜0.05);(2) Feeding PPAM,CCP resulted in higher villouslength to crypt depth ratio in Duodenum and Jejunum(P＜0.05); Both CCP and ANTwere increased significantly villous height (P＜0.05) compared with CR.3. Effects of polysaccharides on immune function of early-weaned pigletsThe results showed: (1) Compared with CR, the concentrations of IgG and IgMin serum of PPAM were significantly increased (P＜0.05), while CCP and CPAM weretended to increase the concentration of IgG and IgM respectively. (2) Peripherallymphocyte transformation of PPAM,CCP were increased significantly comparedwith ANT(P＜0.05), while were lower tendency than CR.(3) adding PPAM,CPAM,CP were greater in the number of white blood cell and lymphocyte than CR,but riotsignificantly(P＞0.05). Red blood cell numbers were higher significantly after feedingPPAM and ANT(P＜0.05). (4) The index of spleen of PPAM and CPAM were higherthan that of CR(P＜0.01;P＜0.05 respectively), the index of spleen of PPAM wereenhanced significantly compared with CCP and ANT respectively(P＜0.05);Compared with CR the index of thymus of CCP and CPAM were greatly highersignificantly(P＜0.01), while the index of thymus of PPAM and ANT wereimproved(P＜0.05).(5)dietary supplementation of PPAM improved the numbers ofintestinal villous epithelium goblet cells(P＜0.05), enhanced the numbers ofintraepithelial lymphocytes (IELs) in villous epithelium of duodenum andileum(P＜0.05); dietary supplementation of CCP improved the numbers of jejunumand ileum villous epithelium goblet cells(P＜0.05), enhanced the numbers ofintraepithelial lymphocytes (IELs) in villous epithelium of ileum(P＜0.05). (6) dietarysupplementation of PPAM,CPAM and CCP increased the concentration of IFN-γ,IL-6 in serum, the serum TNF concentration of PPAM and CCP were higher thanthat of CR(P＜0.05); TNF-a,IFN-γand IL-6 mRNA expression of cytokines gene ofspleen tissue were increased by feeding PPAM,CCP,CPAM increased TNF-amRNA expression of cytokines gene of spleen tissue compared with CR(P＜0.05). It was concluded that dietary supplementation of PPAM,CPAM,CCP increasedgrowth performance and the hormone levels, accelerated lymphocyte transformationand the growth of apparatus, improved the serum concentration of cytokines andIgM,IgG, enhanced mRNA expression of cytokines gene of spleen tissue.increasedthe beneficial bacteria, promoted villous growth and the development of immunologiccells in intestinal, achieved the purpose of enhancing animal immunologic function,dietary supplementation of PPAM and CCP were best in our experiment.