63. Heat stress impairs performance parameters, immunity and increases Salmonella enteritidis migration to spleen of broilers chickens
Stressful stimuli are known to change the immune function. A relevant environmental stress to the poultry production is the heat stress. Salmonella spp. is one of the most important zoonotic pathogens worldwide. The aim of our work was search for effects of heat stress on broilers chickens infected with Salmonella enteritidis (SE), searching for a neuroimmune relationship. Two hundred and sixty chickens were divided in four groups:control (C); heat stress (HS); salmonella + control (PC); and salmonella + heat stress (PHS). The chickens were infected or not with Salmonella enteritidis (10 6 UFC/animal). Both HS and PHS groups were exposed to 31 ± 1 °C (10 h/day) from day 35 to 42. At the end of stress (42 nd day), we observed that heat stress decreased performance parameters such as body weight ( p p ; P p β , IL-10, TGF- β , AvBD4, AvBD6 and TLR-2 expression in chickens infected with SE. Heat stress also induced moderate enteritis in chickens of PHS group; additionally, heat stress increased bacterial migration to the spleen ( p Salmonella migration to the spleen.