Weaned-pig immunology and stress

Alterations in the immune response after weaning are influenced by the neur oendocrine system through the release of catecholamines as well as the dire ct sympathetic innervation of immune organs. Suppression of the immune syst em can occur after glucocorticoid release as well as from infectious agents . Recent data also indicate that chronic immune activation results in reduc ed growth performance. Higher levels of insulinlike growth factor were foun d in animals with lowered immune activation, leading to improved growth per formance.