壳寡糖与屎肠球菌对肉仔鸡生长性能、免疫功能及肠道短链脂肪酸含量的影响

Effects of Chitooligosaccharides and Enterococcus faecium on the Growth Performance, Immune Function and Concentration of Intestinal Short Chain Fatty Acids of Broilers

本试验旨在探究饲粮中添加壳寡糖(COS)和鸡源屎肠球菌PNC01(PNC)对脂多糖(LPS)诱导的肉鸡炎症反应的调节作用。选取1日龄健康且体重相近的AA公雏560羽,采用2(LPS刺激/非LPS刺激)×2(添加COS/不添加COS)×2(添加PNC/不添加PNC)三因素试验设计,共8个处理,每处理7重复,每重复10只鸡,试验期21 d。采用玉米-豆粕型基础饲粮,试验饲粮分别在基础日粮基础上添加COS(200 mg/kg)和PNC(1×109 CFU/kg)。于试验第17、19、21天,刺激组腹腔注射LPS(1 mg/kg体重),对照组注射等量生理盐水。结果表明:LPS刺激降低肉鸡采食量(P<0.01),破坏肠道形态,降低盲肠食糜中丁酸含量和血清IgA水平(P<0.05),引起脾脏肿大,上调IL-1β和IL-8 mRNA表达(P<0.01);添加COS缓解LPS刺激肉鸡采食量的下降(P<0.05),提高盲肠丙酸和丁酸含量(P<0.05),COS降低脾脏指数和回肠IL-8 mRNA表达量(P<0.05),有下调脾脏IL-1βmRNA表达的趋势(P<0.1);PNC可提高21 d肉鸡血清IgA含量(P<0.05),降低肉仔鸡脾脏指数(P<0.01);非LPS刺激时,同时添加COS和PNC可提高盲肠中乙酸含量(P<0.05)。可见,添加COS和PNC均能缓解LPS刺激导致的脾脏肿大,缓解炎症反应,改善LPS刺激对肉仔鸡的不利影响。

The present study was conducted to investigate the effects of chitooligosaccharides(COS)and chicken-origin Enterococcus faeciums PNC01(PNC)supplementation on LPS-stimulated inflammatory response in broiler chickens.A total of 560 male Arbor Acres broilers(1-d-old)were randomly assigned to 8 groups(7 replicates per group with 10 birds in each replicate).A 2(with or without LPS challenge)×2(adding COS or not)×2(adding PNC or not)arranged experiment was designed.The basal diet was corn-soybean meal diets and the test groups were fed COS(200 mg/kg)and PNC(1×109 CFU/kg).From d 17 on,the infected groups were intraperitoneally injected with LPS(1 mg/kg body weight)every other day,and the non-infected group was injected with sodium,the injection repeated for three times,and this trial lasted 21 days.Results showed that the feed intake during 17-21 d decreased significantly after treatment with LPS(P<0.01).Chickens that were challenged by LPS had a lower ileal villus height(P<0.01).Compared with the control group,the levels of serum IgA and cecal chyme butyric acid decreased(P<0.05).LPS trestment increased spleen index(P<0.01).LPS resulted in increased relative mRNA expression of IL-1β(P<0.01).The addition of COS alleviated the feed intake reduction of broilers induced by LPS stimulation(P<0.05).The COS-fed birds had higher(P<0.05)propionic acid and butyric acid level in cecal chyme.Besides,COS significantly decreased spleen index(P<0.05),down-regulated IL-8 mRNA expression in ileum(P<0.05),and trended to down-regulate the IL-1βmRNA expression in spleen induced by LPS infection(P<0.1).The PNC-fed birds had higher(P<0.05)IgA level in serum,the addition of PNC suppressed the increase of spleen index after injections(P<0.05).Under non-LPS stimulation conditions,COS along with PNC significantly increased the acetic acid content in the cecal chyme(P<0.05).The results revealed that both COS and PNC alleviate the spleen enlargement due to LPS stimulation,and there by alleviate the inflammatory response of treated broilers.