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Từ điển khoa học động vật vần I | Immune System Nutrition Effects Rodney W. Johnson University of Illinois Urbana Illinois U.S.A. Jeffery Escobar Baylor College of Medicine Houston Texas U.S.A. INTRODUCTION The National Research Council NRC nutrient requirements for animals can be defined as nutrient levels adequate to permit the maintenance of normal health and productivity. Failure to provide a diet that fulfills the minimal requirements established by the NRC for any nutrient will ultimately immunocompromise the animal and render it more susceptible to infectious disease. Because nutrient requirements to support optimal productivity are well defined marked deficiencies in protein amino acids or trace nutrients are not likely to occur in animals reared in commercial situations. However the nutrient requirements for optimal productivity may not equal those for optimal immunity because the NRC requirements have been determined from experiments conducted in laboratory situations where infectious disease is minimal. Thus an important issue that has been the focus of nutritional immunology research is whether specific nutrients fed at or above NRC-recom-mended levels could be used to modulate the animal s immune system in a beneficial manner. THE IMMUNE SYSTEM The cells of the immune system and their responses to infection are obviously complex but can be partitioned into two separate but interacting components those that provide innate immunity and those that provide acquired or adaptive immunity Fig. 1 . Both components are influenced by nutrition Table 1 . The component of the immune system that protects the host animal but does not distinguish one pathogen from another provides innate immunity. For example macrophages recognize pathogens using relatively indiscriminant receptors. They ingest and degrade microorganisms and provide important signals e.g. cytokines that orchestrate other aspects of the immune response. The innate immune system is inherent and the capacity of it to respond does not .
