Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/1/2004
Publication Date: 10/1/2004
Citation: Miles, D.M., Branton, S.L., Lott, B.D. 2004. Atmospheric ammonia is detrimental to the performance of modern commercial broilers. Poultry Science 83:1650-1654.
Interpretive Summary: Scientific literature reports atmospheric ammonia can reduce bird performance, increase susceptibility to disease and increase subsequent mortality, but quantification of effects are based on older genetic stock. With exposure to ammonia early in the growout at a concentration of 50 ppm, modern commercial broilers experienced a reduction in body weight of 200 g or 0.44 pounds at seven weeks of age. Birds exposed to 25 ppm were not deficient in body weight when compared to control birds. A simple equation was developed for predicting body weight decline of male broilers in ammoniated atmospheres. The results can be used to demonstrate the negative impact on profits to poultry farmers while promoting the need for controlling ammonia and improving overall bird health. Controlling ammonia to provide 10% of growers with an average increase of 45 g or 0.1 pound per bird equates to an increase in profit of $26.2 million (based on the 2002 farm value of $0.305/lb).
Technical Abstract: Atmospheric ammonia inhibits broiler performance. Quantified effects are based on older genetic stock with a seven-week body weight of 2000 g compared to 3200 g today. To assess the impact on present day broilers, two trials were conducted exposing broilers to graded levels of aerial ammonia: 0, 25, 50, and 75 ppm. Sixty, day-old chicks were placed in environmentally controlled chambers, group weighed weekly, and processed with yield determined at 7 weeks of age. Final body weight was significantly depressed by 6% and 9% for the 50 and 75 ppm concentrations as compared to the 0 ppm ammonia level. Also, mortality was significantly greater at the 75 ppm ammonia concentration, 13.9% compared to 5.8% for the 0 ppm treatment. Percentage yield of deboned meat per bird decreased numerically with increasing exposure to ammonia, but was not statistically significant. Though current genetic stock reaches growout weights approximately 60% greater than two decades ago, relative quantified effects of ammonia exposure were similar. Additionally, statistical analysis of the results provided a simple equation for predicting body weight decline of male broilers for ammonia exposure.