The present experiment was conducted to investigate effects of conjugated linoleic acid (CLA) on growth performance, oocyst shedding, duodenumal mucosal immune response and lip-id peroxidation of broiler chicks infected with E. aceruvlina. After 21 days of dietary supplementation with either basal diets or 1. 5% CLA diets, half of replicates in each treatment were inoculated with 10 000 E. aceruvlina sporulated oocysts. Compared with basal diets, 1. 5% CLA diets ameliorated growth inhibition (P＜0. 01＝ , and decreased oocyst shedding between 6-9 d post-inoculation resulted from E. aceruvlina infection (P＜0. 01＝. Whether infection or not, duodenumal intraepithelial lymphocyte (IEL) CD8+T lymphocyte subpopulations were significantly higher in chicks fed CLA diet than the controls (P＜0. 05＝, but interferon γ (IFNγ) gene expression was not (P＞0. 05). Dietary CLA notably suppressed the increase of MDA in duodenumal mucosa (F＜0. 05＝, and inhibited the decrease of glutathione (GSH) concentration (P＜0. 01＝ resulted from E. aceruvlina infection, but didn; t influence the activity of total superoxide dismutase (TSOD) and catalase (CAT)(P＞0. 05). Dietary CLA decreased oocyst shedding and ameliorated growth ihibition of broiler chicks resulted from E. aceruvlina infection at least in part through increasing duodenumal IEL CD8+ T lymphocyte subpopulations and inhibiting the decrease of duo-denumal mucosal GSH in broiler chicks.%研究日粮添加共轭亚油酸(Conjugated linoleic acid,CLA)对人工感染堆型艾美耳球虫(E.aceruvlina)肉仔鸡的生长、卵囊排出量、肠道黏膜免疫反应和氧化应激状态的影响.肉仔鸡在采食21d的基础日粮或1.5％CLA日粮后,每个处理一半重复人工感染球虫,每只肉仔鸡口服10 000个E.aceruvlina孢子化卵囊.结果如下:与基础日粮相比,CLA日粮缓解因E.acervulina感染而造成的肉仔鸡生长抑制(P＜0.01),并降低感染后6～9 d期间的卵囊排出量(P＜0.01).无论有无球虫感染,日粮添加CLA均提高肉仔鸡十二指肠上皮内淋巴细胞(Intestinal intraepithelial lymphocyte,IEL)的CD8+T淋巴细胞比例(P＜0.05),而对肉仔鸡十二指肠干扰素γ(Interferonγ,IFNγ)基因表达没有影响(P＞0.05).日粮CLA显著抑制因E.acervulina感染而诱导的十二指肠黏膜丙二醛( Malondialdehyde,MDA)含量的提高(P＜0.05),显著阻止因E.acervulina感染而诱导的肉仔鸡十二指肠黏膜谷胱甘肽(Glutathione,GSH)水平的降低(P＜0.01),但不影响总超氧化物歧化酶(Total superoxide dismutase,TSOD)和过氧化氢酶(Catalase,CAT)的活性(P＞0.05).日粮添加CLA减少E.aceruvlina感染后肉仔鸡卵囊排出量,缓解E.aceruvlina感染引起的生长抑制,其抗球虫特性在一定程度上与提高肉仔鸡十二指肠IEL的CD8+T淋巴细胞比例和阻止GSH水平的降低有关.
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