脂磷壁酸对肉鸡感染鼠伤寒沙门菌的影响

Effects of lipoteichoic acid on broilers infected with Salmonella Typhimurium

本研究旨在探讨脂磷壁酸(LTA)对感染鼠伤寒沙门菌(Salmonella Typhimurium)的肉鸡生长性能、免疫功能及肠道健康的影响。将96只1日龄体重相近的健康仔鸡随机分成空白组(Con,基础日粮),脂磷壁酸组(LTA,基础日粮+200μg/mL LTA),鼠伤寒沙门菌感染组(ST,基础日粮)和脂磷壁酸预防组(LTA+ST,基础日粮+200μg/mL LTA),每组3个重复,每个重复8只。LTA+ST组和ST组在14日龄感染鼠伤寒沙门菌,试验周期为21 d。结果显示:LTA+ST组缓解了鼠伤寒沙门菌感染导致的肉鸡体重下降(P<0.05),提高了肉鸡生存率;与ST组相比,饲喂LTA增加了肉鸡空肠和回肠的绒毛高度(P<0.05)和绒毛高度/隐窝深度(V/C)比值(P<0.05),降低了空肠和回肠的隐窝深度(P<0.05);LTA+ST组肉鸡空肠和回肠中白介素-1β(IL-1β)和肿瘤坏死因子(TNF-α)含量显著低于ST组(P<0.01);LTA+ST组肉鸡回肠中杯状细胞和潘氏细胞数量显著高于ST组,鸡黏蛋白2(Muc2)和鸡防御素α6(DEFA6)含量显著升高(P<0.05)。综上,饲喂LTA能够改善肉鸡肠道形态,降低炎症因子的表达,增加分泌细胞数量,促进抗菌肽的表达,提高机体免疫力,促进肠道屏障发育,有效缓解鼠伤寒沙门菌感染对肉鸡肠道的损伤,维护肉鸡的肠道健康。

This study aimed to investigate the effects of lipoteichoic acid(LTA)on the growth performance,immune function,and intesti⁃nal health of broiler chickens infected with Salmonella Typhimurium(S.Typhimurium).Ninety-six one-day-old healthy broilers with simi⁃lar body weight were selected and randomly divided into 4 groups,each with three replicates of eight chickens.The groups included a control group(Con,basal diet),an LTA treatment group(LTA,basal diet+200μg/mL LTA),an ST infection group(ST,basal diet),and an LTA prevention group(LTA+ST,basal diet+200μg/mL LTA).The LTA+ST and ST groups were inoculated with ST at 14 days of age,and the experiment lasted 21 d.The results showed as follows:The LTA+ST group mitigated the decline in body weight(P<0.05)and en⁃hanced the survival rate of broiler chickens induced by ST infection.Compared with the ST group,feeding with LTA increased villus height(P=0.067,P<0.05)and V/C ratio(P<0.05)in the duodenum and jejunum of the broiler chickens,reduced the crypt depth in these re⁃gions(P<0.05).The LTA+ST group exhibited significantly lower levels of interleukin-1β(IL-1β)and tumor necrosis factor-alpha(TNF-α)in the duodenum and jejunum,compared with the ST group(P<0.01).In the jejunum of the LTA+ST group,there was a signifi⁃cant increase in goblet cells and Paneth cells,compared with the ST group,along with elevated the expression levels of chicken mucin 2(Muc2)and chicken enteric alpha-defensin 6(DEFA6).In summary,feeding broiler chickens with LTA improved their intestinal morphol⁃ogy,downregulated the expression of inflammatory factors in them,increased the abundance of secretory cells in them,promoted their antimicrobial peptide secretion,enhanced their immune response,facilitated their intestinal barrier development,effectively alleviated ST in⁃fection-induced damage to their intestines,and maintained their intestinal health.