Atmospheric Ammonia and Broiler Cockerel Performance

Effects of atmospheric ammonia at 0, 25, and 50 ppm in relation to time on broiler cockerels were studied. Average body weights, feed efficiencies, air sac scores, and paired-lung and bursa of Fabricius weights were determined from 10 birds per replicate at 28, 40, and 49 days of age. Carcass condemnations and USDA carcass grades were measured at 49 days of age. Feed efficiency at 49 days of age was significantly affected (P≤.01) by ammonia levels. Broilers subjected to 50 ppm ammonia from 1 through 49 days were least efficient. Broilers subjected to 50 and 25 ppm ammonia from 1 to 28 days and adjusted to 25 ppm ammonia from 29 to 49 days were next least efficient, followed by 50 and 25 ppm ammonia groups from 1 to 28 days and reduced to 0 ppm ammonia from 29 to 49 days. Control birds (0 ppm ammonia) from 1 to 49 days were most efficient. Average body weights, air sac scores, lung weights, and bursa of Fabricius weights as a percentage of live body weight, carcass grades, and condemnations were not significantly affected by treatment. The results indicated ammonia levels of 25 and 50 ppm from day of age in conjunction with Newcastle infectious bronchitis (Mass.) vaccination at 21 days of age can adversely affect feed efficiency of broiler cockerels and thereby increase cost of production.