本试验旨在考察饲粮添加精氨酸( arginine,Arg)对免疫应激仔猪生长性能和肠道组织细胞膜外Toll样受体(TLR2、TLR4、TLR5、TLR6)基因表达的影响.选用(24±1)日龄的断奶、平均体重(7.19±0.63) kg的杜洛克×长白×大白公猪20头,随机分为4个处理,分别为饲喂基础饲粮+注射生理盐水(对照组)、饲喂基础饲粮+注射沙门氏杆菌活疫苗(S.C500)(S.C500组)、饲喂基础饲粮添加0.5％ Arg+注射S.C7500(0.5％ Arg组)和饲喂基础饲粮添加1.0％ Arg+注射S.C500(1.0％ Arg组),每个处理5个重复,每个重复1头仔猪.应激处理于第8天实施,肌肉注射S.C500 4mL.试验期17d.第8(免疫应激前)、9、11、18天采集血样测定血清沙门氏菌抗体水平和IL-6浓度,第18天仔猪屠宰采集空肠和回肠组织样品,测定Toll样受体mRNA表达量.结果表明:与对照组相比,仔猪肌肉注射S.C500不同程度地降低了平均日增重(ADG) (P ＜0.10)和平均日采食量(ADFI)(P＜0.05),显著增加了在第9、11和18天血清IL-6浓度(P＜0.05),同时显著上调了空肠和回肠组织中TLR4和TLR5 mRNA表达量(P＜0.05)；添加Arg(0.5％和1.0％)能够缓减疫苗注射导致的以上抑制的效应,显著抑制了仔猪血清IL-6浓度、空肠和回肠TLR4和TLR5 mRNA表达量的上调(P＜0.05).结果提示,饲粮添加Arg能显著减缓因S.C500注射引起的断奶仔猪肠道TLR4和TLR5基因的过度表达、血清IL-6浓度的升高,从而缓解免疫应激对仔猪的损伤.%This trial was conducted to study the effect of arginine (Arg) supplementation on growth perform ance and genes expression of cell-surface toll-like receptors (TLR2 , TLR4, TLR5 and TLR6) in intestinal tis sues of weaned piglets under immune stress. Twenty male weaned piglets [ (Duroc x Landrace x Yorkshire), (24 ± 1) days of age, average body weight of ( 7. 19 ± 0. 63) kg] were randomly assigned to 4 treatments with 5 replicates in each treatment and 1 piglet per replicate. Piglets were fed basal diet + injected sterile saline (control group) , fed basal diet + injected live vaccine of Salmonella choleraesuis 500 (S. C500) (S. C500 group), fed basal diet supplemented with 0. 5% Arg + injected 5. C500 (0. 5% Arg group), and fed basal diet supplemented with 1.0% Arg + injected S. C500 (1.0% Arg group), respectively. The injection of 4 mL S. C500 or sterile saline was carried out on day 8. The trial lasted for 17 d. Blood samples were collected to determine serum Salmonella antibody level and interleukin-6 (IL-6) concentration on day 8 (before injection) , day 9, day 11 and day 18. Piglets were slaughtered and jejunum and ileum tissue samples were collected for evaluation of mRNA expression levels of toll-like receptors on day 18. The results showed as follows; compared with the control group, injection of S. C500 decreased the ADG (P <0.10) and ADFI (P < 0.05) of piglets to a different extent, significantly increased serum IL-6 concentration on day 9, day 11 and day 18 (P <0.05), as well as mRNA expression levels of TLR4 and TLR5 in jejunum and ileum tissue (P < 0.05); Arg supplementation (0. 5% and 1.0% ) alleviated inhibitive effects induced by S. C500 challenge, decreased serum IL-6 concentration, and inhibited mRNA expression levels of TLR4 and TLR5 in jejunum and ileum tissue (P<0. 05). These results indicate that Arg supplementation can alleviate the over-expression of TLR4 and TLR5 mRNA in intestinal tissues and the excessive production of serum IL-6 induced by S. C500 challenge, which are beneficial to alleviating damage induced by immune stress.
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