Spears J W
Department of Animal Science and Interdepartmental Nutrition Program, CB# 7621, North Carolina State University, Raleigh, NC 27695-7621, USA.
Proc Nutr Soc. 2000 Nov;59(4):587-94. doi: 10.1017/s0029665100000835.
Complex inter-relationships exist between certain micronutrients, immune function and disease resistance in cattle. Several micronutrients have been shown to influence immune responses. The relationship between deficiencies of some micronutrients and disease resistance is less clear. A number of studies have indicated that Cr supplementation may improve cell-mediated and humoral immune response as well as resistance to respiratory infections in stressed cattle. With respiratory-disease challenge models Cr generally does not affect disease resistance. Deficiencies of Cu, Se, vitamin E and Co in cattle reduce the ability of isolated neutrophils to kill yeast and/or bacteria. Cu deficiency reduces antibody production, but cell-mediated immunity is generally not altered. However, Cu deficiency appears to reduce production of interferon and tumour necrosis factor by mononuclear cells. Numerous studies have linked low vitamin E and/or Se status to increased susceptibility of dairy cows to intramammary infections. In contrast to findings in laboratory animals, marginal Zn deficiency does not appear to impair antibody production or lymphocyte responsiveness to mitogen stimulation in ruminants. Co deficiency has been associated with reduced resistance to parasitic infections. It is well documented that vitamin A-deficient animals are more susceptible to various types of infections. beta-Carotene, possibly via its antioxidant properties, may affect immune function and disease resistance independent of its role as a precursor of vitamin A.
牛体内某些微量营养素、免疫功能和抗病能力之间存在复杂的相互关系。已有研究表明，多种微量营养素会影响免疫反应。一些微量营养素缺乏与抗病能力之间的关系尚不清楚。多项研究表明，补充铬可能会改善应激状态下牛的细胞介导免疫和体液免疫反应，以及对呼吸道感染的抵抗力。在呼吸道疾病挑战模型中，铬通常不会影响抗病能力。牛体内铜、硒、维生素E和钴缺乏会降低分离出的中性粒细胞杀死酵母和/或细菌的能力。铜缺乏会减少抗体产生，但细胞介导免疫通常不会改变。然而，铜缺乏似乎会降低单核细胞产生干扰素和肿瘤坏死因子的能力。大量研究表明，维生素E和/或硒水平低会增加奶牛患乳房内感染的易感性。与实验动物的研究结果相反，边缘性锌缺乏似乎不会损害反刍动物的抗体产生或淋巴细胞对有丝分裂原刺激的反应能力。钴缺乏与对寄生虫感染的抵抗力降低有关。有充分的文献记载，维生素A缺乏的动物更容易受到各种类型感染的影响。β-胡萝卜素可能通过其抗氧化特性，独立于其作为维生素A前体的作用，影响免疫功能和抗病能力。
