中文摘要：

本试验旨在研究以递增饲粮非纤维性碳水化合物与中性洗涤纤维比（ NFC/NDF）方式诱导奶山羊发生亚急性瘤胃酸中毒（ SARA）后,血浆细胞因子和激素含量的变化。选取9只体况良好,体重接近的泌乳期莎能奶山羊,随机分为3组（对照组、SARA组、恢复组, n=3）,对照组饲喂基础饲粮,SARA组和恢复组先后饲喂NFC/NDF为1.40、1.79、2.31、3.23的4种试验饲粮诱导SARA发生,每种饲喂15 d,恢复组奶山羊诱导SARA后自由采食青干草30 d。对照组3只羊分别在饲养30、60（与SARA组同时）和90 d（与恢复组同时）屠宰。结果表明：1） SARA长期提高了血浆LPS浓度,恢复组与SARA组差异不显著（ P＞0.05）。2）与对照组相比,SARA组奶山羊血浆中促炎性细胞因子肿瘤坏死因子-α（ TNF-α）、白细胞介素（ IL）-1β和IL-6含量呈升高趋势（P＞0.05）,IL-2含量显著升高（P＜0.05）,IL-8含量呈降低趋势（P＞0.05）,γ-干扰素（IFN-γ）含量显著降低（P＜0.05）,抗炎性细胞因子IL-4和IL-10含量均呈降低趋势（P＞0.05）；SARA组奶山羊血浆中生长激素、胰岛素样生长因子-Ⅰ、胰岛素含量变化不显著（P＞0.05）,催乳素（PRL）和皮质醇（COR）含量均显著升高（P＜0.05）。3）与SARA组相比,恢复组奶山羊血浆中TNF-α、IL-1β、IL-2、IL-6这些促炎性细胞因子的含量仍持续性升高,其中IL-1β和IL-2含量显著升高（P＜0.05）；恢复组奶山羊血浆中PRL含量仍维持与SARA组同一水平（P＞0.05）,而COR含量则回归到对照组水平（ P＞0.05）。本研究结果显示,SARA可引起奶山羊血浆中长时间含有一定量的LPS,引发机体免疫和炎症反应,并引起内分泌激素的变化,这一系列变化导致奶山羊长期处于应激状态。

英文摘要：

This experiment was conducted to investigate the effects of subacute ruminal acidosis （ SARA） in-duced by gradually increasing dietary non-fiber carbohydrate/neutral detergent fiber ratios （ NFC/NDF ） on plasma hormone and cytokine contents in dairy goats. Nine healthy lactating Saanen dairy goats with similar body weight were randomly allocated to three groups （ control group, SARA group and recovery group, n=3 ） . Dairy goats in control group were fed a basal diet;those in SARA group and recovery group were fed diets with different NFC/NDF （1.40, 1.79, 2.31 and 3.23, respectively, each for 15 days）, which gradually in-duced SARA; those in recovery group were ad libitum fed green hay for 30 days after SARA. The three goats in control group were slaughtered on days 30, 60 （ together with SARA goup） and 90 of feeding （ together with recovery group） . The results showed as follows：1） plasma lipopolysaccharide （ LPS） concentration was increased for a long time as a result of SARA challenge, and there was no significant difference between SARA group and recovery group （ P〉0.05） . 2） Compared with control group, the contents of plasma tumor necrosis factor-α （TNF-α）, interleukin （IL）-1β and IL-6 tended to be increased （P〉0.05）, and IL-2 content was significantly increased （P〈0.05）, but interferon-γ （IFN-γ） content was significantly decreased （P〈0.05）, and the contents of plasma IL-4, IL-8 and IL-10 tended to be decreased in SARA group （ P〉0.05）; the con-tents of plasma growth hormone, insulin-like growth factor-Ⅰ and insulin were not changed （P〉0.05）, and the contents of prolactin and cortisol were significantly increased （ P〈0.05） . 3） Compared with SARA group, the contents of plasma TNF-α, IL-1β, IL-2, IL-6 in recovery group were still persistently increased, in which IL-1β and IL-2 contents were significantly increased （ P〈0.05）; plasma prolactin content stayed at the same level as SARA group （ P〉0.05） ,