Immune system activation effect on lysine requirements of pigs

摘要

ACTIVATION of the immune system is a natural biological response that occurs after an animal has been exposed to a pathogenic (such as bacterial or viral) or non-pathogenic (such as an endotoxin) antigen.First, the presence of an antigen results in the release of cytokines — such as interleukin-1, interleukin-6 and tumor necrosis factor — that activate the immune system (Klasing and Korver, 1997). These cytokines also alter the animal's metabolic stateby depressing feed intake as well as partitioning nutri-ents away from tissue deposition and towards immune activity.