Heat stress effect on the intestinal epithelial function of broilers fed methionine supplementation

ABSTRACT The objective of this study was to evaluate the effect of dl-methionine supplementation on the expression of genes related to immune function and intestinal integrity in the jejunum and ileum of 21- or 42-day-old broilers subjected to 38°C for 24 hours. Broilers of 1–21 and 22–42 days of age were divided into two treatments related to methionine supplementation: without dl-methionine supplementation (MD) or recommended level of dl-methionine (MS). In addition, the animals were either maintained at a comfort environment or exposed to heat stress (HS) (38°C for 24 hours, starting on day 20 or day 41 for Experiments 1 and 2, respectively). Heat stress increased body temperature and the respiratory rate of the birds in both the experimental periods evaluated (1-21 and 22-42 days of age) (body temperature: P = 0.0010 and P = 0.0005, respectively; respiratory rate: P