Latshaw J D
Department of Poultry Science, Columbus, OH 43210.
Vet Immunol Immunopathol. 1991 Nov;30(1):111-20. doi: 10.1016/0165-2427(91)90012-2.
Nutritionists must formulate diets that supply adequate amounts of nutrients from five major groups. These are carbohydrate, protein (amino acids), fat, minerals and vitamins. Carbohydrate is usually a cheaper source of energy than fat, but fat is often used to increase the caloric concentration of the diet. Variations in energy intake which may effect immunocompetence usually result from management practices rather than diet formulation. Feed restriction for broiler breeders and withholding feed in forced molting practices may affect immunocompetence. Feed restriction causes higher plasma corticosterone levels, which are known to decrease the immune response, possibly through effects on cytokines. Excessive feed, through forced feeding, may also have short-term effects on indicators of humoral immunity. Protein and amino acid nutrition have been studied in relation to immunocompetence. The level of dietary amino acid needed to maximize growth and feed efficiency will also generally maximize measures of immunocompetence. The level of amino acids needed for maximum growth is lower in chicks which have been immunologically stressed than in chicks which have not. An immune response changes metabolism so that less growth occurs, thereby decreasing the need for amino acids. Dietary levels of minerals can affect immunocompetence. While deficient levels of sodium and chloride decrease humoral immunity, levels of these nutrients which supported maximum growth also supported maximal humoral immunity. Low dietary zinc levels did not affect indicators of immunocompetence in the chick. The effect of fat soluble vitamin levels on the immune system has been studied. Vitamin A is needed to maintain epithelial tissue and prevent infection. Cellular immune response is decreased when the chick is deficient in this nutrient. Several indicators of immune responsiveness are depressed when chicks are vitamin E and/or selenium deficient. Since these nutrients serve as antioxidants, cellular integrity may be affected by a deficiency. Cellular integrity is very important for receiving, and responding to the messages needed to coordinate an immune response. High levels of vitamin E (greater than 10 times the required level) have been found to be immunostimulatory.
营养学家必须制定能从五大类中提供足够营养素的饮食方案。这五大类分别是碳水化合物、蛋白质（氨基酸）、脂肪、矿物质和维生素。碳水化合物通常是比脂肪更便宜的能量来源，但脂肪常被用于提高饮食的热量浓度。可能影响免疫能力的能量摄入变化通常源于管理措施而非饮食配方。对肉种鸡进行限饲以及在强制换羽操作中停喂饲料可能会影响免疫能力。限饲会导致血浆皮质酮水平升高，已知这会降低免疫反应，可能是通过对细胞因子的影响。通过强制喂食摄入过多饲料也可能对体液免疫指标产生短期影响。人们已经研究了蛋白质和氨基酸营养与免疫能力的关系。使生长和饲料效率最大化所需的日粮氨基酸水平通常也会使免疫能力指标最大化。与未受免疫应激的雏鸡相比，受到免疫应激的雏鸡实现最大生长所需的氨基酸水平更低。免疫反应会改变新陈代谢，从而使生长减少，进而降低对氨基酸的需求。日粮中的矿物质水平会影响免疫能力。虽然钠和氯水平不足会降低体液免疫，但支持最大生长的这些营养素水平也支持最大体液免疫。日粮锌水平低对雏鸡的免疫能力指标没有影响。人们已经研究了脂溶性维生素水平对免疫系统的影响。维持上皮组织和预防感染需要维生素A。雏鸡缺乏这种营养素时，细胞免疫反应会降低。雏鸡缺乏维生素E和/或硒时，几种免疫反应指标会受到抑制。由于这些营养素具有抗氧化作用，缺乏可能会影响细胞完整性。细胞完整性对于接收和响应协调免疫反应所需的信息非常重要。已发现高水平的维生素E（高于所需水平的10倍）具有免疫刺激作用。
