9 subclinical ketosis cows that delivered in 14 days (1.0 mmol · L-1≤serum β-hydroxybutyrate ＜2.6 mmol·L-1) were selected as the test group from 43 Holstein cows (Somatic cell count ＜200 000·mL-1 ).The control group (serum β-hydroxybutyrate ＜1.0 mmol · L-1) which contained 9 healthy cows was paired according to days in milk, age, parity and milk yield.Blood samples were collected for analysis of several kinds of white blood cell counts, phagocytosis function and chemotaxis function of neutrophils,lymphocyte transformation rate and the levels of immunoglobulin G, interleukin-2, interleukin-8 and γ-interferon in the serum.The results showed that white blood cell count, the number of neutrophils and lymphocyte, the rate of phagocytosis and the chemotactic index of neutrophils in the blood of the subclinical ketosis cows were significantly lower than that of control group (P＜0.05).ILymphocyte transformation rate was significantly lower than that of control group (P＜0.01).Serum level of γ-IFN was significantly lower than that of control group (P＜0.05).Subclinical ketosis decreased immunological function in dairy COWS.%从43头荷斯坦奶牛(体细胞数＜200 000个·mL-1)中筛选出处于分娩第14天的自然发生亚临床酮病的9头奶牛作为试验组(1.0 mmol·L-1≤血清β-羟丁酸＜2.6 mmol·L-1),根据泌乳天数、年龄、胎次、产奶量配对的9头健康奶牛作为对照组(血液β-羟丁酸＜1.0 mmol·L1),检测不同种类白细胞数量、中性粒细胞吞噬功能、趋化功能、淋巴细胞转化率以及血液免疫球蛋白G(IgG)、白细胞介素-2(IL-2)、白细胞介素-8(IL-8)和γ-干扰素水平(IFN-γ).结果显示试验组奶牛外周血白细胞总数、中性粒细胞数、淋巴细胞数、中性粒细胞吞噬率和趋化指数显著低于对照组(P＜0.05),淋巴细胞转化率极显著低于对照组(P＜0.01),血清γ-IFN水平显著低于对照组(P＜0.05).亚临床酮病可以使奶牛免疫功能降低.
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