Counteracting heat stress 
in poultry production

Modern broiler breeds have a ?continuously increasing growth rate and feed efficiency, which coincides with a reduced heat tolerance. Housing broilers at high ambient ?temperatures adversely affects ?performance, intestinal integrity, immune response, and meat quality. Feed additives that alleviate the ?consequences of heat stress, among which phytogenic feed additives, ?generally exert clear antioxidant effects. Birds are homeothermic. Their thermoneutral zone lies between 18 and 36°C, but the