Immune System Stimulation in the Pig: Effect on Performance and Implications for Amino Acid Nutrition

摘要

Even in well managed pig production facilities pigs are routinely exposed to disease-causing pathogens that negatively impact animal productivity. It has been estimated that the cost of disease represents a loss of $USD640 million per year for the United States swine industry alone. Immune system stimulation (ISS; disease) alters nutrient metabolism and utilization and, thus, imposes qualitative and quantitative consequences for the development of optimum feeding strategies. ISS alters the animals’physiology and metabolism via a complex system involving innate and adaptive immune response, a number of cytokines and acute phase proteins, as well as the central nervous system. Daily requirement for dietary energy is decreased during ISS, mainly dueto reduced energy requirement for growth and activity. During ISS and amongst the amino acids (AA), glutamine, arginine, aromatic amino acids (especially tryptophan), threonine and the sulfur containing AA (SAA; methionine and cysteine) deserve special consideration. For some of the metabolic demands for these amino acids may be increased during ISS, without impacting dietary requirements. However, there is evidence to suggest that the immune system’s needs for tryptophan and SAA are increased and impact the optimum dietary amino acid balance during ISS.