口服表面活性素对母猪乳源性免疫力的影响

Effect of orally surfactin on lactogenic immunity in sows

[目的]本文旨在通过给母猪口服表面活性素(枯草芽胞杆菌OKB105发酵产物)以评估其产生的乳源性免疫力,从而提高仔猪肠道免疫力,降低仔猪流行性腹泻(Porcine epidemic diarrhea,PED)发病率。[方法]妊娠母猪日粮添加0.05%的表面活性素(1 g·d^(-1)),产后第1天收集初乳。对乳成分进行分析,然后通过流式细胞术测定初乳中的免疫细胞数量和淋巴细胞的增殖能力,随后进行ELISA试验测定初乳中的细胞因子和抗病毒蛋白含量,最后用空斑试验验证初乳上清抗猪流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)的能力。[结果]母猪口服表面活性素能显著提高初乳中乳蛋白的含量(P<0.05),极显著提高初乳中CD14^(+)单核细胞和CD3^(+)T淋巴细胞的数量(P<0.01),极显著增强初乳中淋巴细胞的增殖能力(P<0.01),极显著提高初乳中IFN-γ和CCL28的含量(P<0.01),显著提高初乳中sIgA、IgG、TGF-β、IL-6和乳铁蛋白的含量(P<0.05)。母猪口服表面活性素能将初乳上清拮抗PEDV的滴度从1∶4提升至1∶16。[结论]口服表面活性素可以提高母猪初乳中细胞免疫和体液免疫水平,为预防新生仔猪PED造成的腹泻提供充足的乳源性免疫力保护。

[Objectives]The paper aimed to evaluate the lactogenic immunity of sows by orally surfactin(fermentation product of Bacillus subtilis OKB105),so as to improve the intestinal immunity of piglets and reduce the incidence rate of Porcine epidemic diarrhea in piglets.[Methods]0.05%surfactin(1 g·d^(-1))was added to the diet of pregnant sows,and colostrum on the first day after delivery was collected.First,the composition of milk was analyzed,and then the number and proliferation capacity of immune cells in colostrum were determined by flow cytometry.Subsequently,ELISA experiments were conducted to determine the content of cytokines and antiviral proteins in milk.Finally,the plaque assay was used to verify the ability of milk supernatant to inhibit Porcine epidemic diarrhea virus.[Results]Oral administration of surfactin significantly increased the content of milk protein in colostrum in sows(P<0.05),significantly increased the number of CD14^(+)monocytes and CD3^(+)T lymphocytes in colostrum(P<0.01),significantly enhanced the proliferation ability of lymphocytes in colostrum(P<0.01),significantly increased the content of IFN-γand CCL28(P<0.01),and significantly increased the contents of sIgA,IgG,TGF-β,IL-6 and lactoferrin(P<0.05).The titer of sow oral surfactin colostrum supernatant against PEDV was 1∶16,while the blank sow was 1∶4.[Conclusions]Oral administration of surfactin could improve the cellular and humoral immune levels in sow colostrum,providing sufficient lactogenic immunity protection against diarrhea caused by neonatal piglet PED.