Overcrowding stress decreases macrophage activity and increases Salmonella Enteritidis invasion in broiler chickens

摘要: Overcrowding stress is a reality in the poultry industry. Chickens exposed to long-term stressful situations present reduction of welfare and immunosuppression. We designed this experiment analyse effects from overcrowding 16 birds/m(2) on performance parameters, serum corticosterone levels, relative weight bursa Fabricius, plasma IgA IgG intestinal integrity, macrophage activity experimental Salmonella Enteritidis invasion. The results study indicate that decreased induced enteritis broiler chickens. When chickens were similarly stressed infected with Enteritidis, there was an increase feed conversion decrease levels Salmonella-infected birds. observed moderate throughout duodenum Salmonella. phagocytosis intensity increased counts livers birds challenged pathogenic bacterium. via hypothalamic-pituitary-adrenal axis associated might influence quality immune barrier integrity small intestine. This effect allowed bacteria migrate through mucosa, resulting inflammatory infiltration nutrient absorption. data strengthen hypothesis control avoidance production are relevant factors for maintenance susceptibility infection.