INFLAMMATION OF THE BRONCHI IN BROILER-CHICKENS, ASSOCIATED WITH BARNDUST AND THE INFLUENCE OF BARN TEMPERATURE

Broiler chickens were raised in separate rooms kept at temperatures of either 27 C or 16 C from 28 through 39 days of age. At the high tempe rature mouth breathing was recorded, but it was absent at the lower te mperature. The number of dust particles in the air was greater in the warm rooms. More than 50% of the chickens in warm rooms had microscopi c lesions in the bronchi of their lungs, whereas fewer than 5% of chic kens in cold rooms had such lesions. Large dust particles were visible in some of the lesions. It was postulated that the increased incidenc e of lung lesions in chickens from warm rooms was due to mouth breathi ng rather than the higher dust levels in the air of these rooms.