Neuroimunomodulation in poutry: effects of E. coli lipopolysaccharide on immune, neuroendocrine and behavioral parameters of broiler chickens

Abstract

Stress is a reality worldwide in poultry production. It is known that in stressful environments there is loss to welfare, productivity and immunity of broilers, resulting in an increased susceptibility of birds to diseases. Neuroimmunomodulation is the scientific area that studies the mutual relationships between the Central Nervous System and the Immune System. In our laboratories, we observed that stress in broilers reduced weight gain and feed intake, decreased the relative weight of the Fabricius bursa, decreased the peritoneal macrophages activity, and increased the serum levels of corticosterone. Also, we observed the presence of discrete enteritis characterized by increased lymphoplasmocytic inflammatory infiltrate in the lamina propria of the jejunum after heat stress in poultry. Experimentally challenging the stressed birds with microorganisms led to a greater migration of these pathogens to the spleen. Accordingly, we also observed that stress induced by high population density was able to decrease the activity of macrophages and increase the migration of microorganisms to the birds' liver showing, once more, a decreased host resistance of birds to infections. The present work aims to continue this line of research, now studying from a neuroimmunomodulation perspective the systemic effects of lipopolysaccharide administration on behavioral, immune and neuroendocrine parameters of poultry. (AU)