Effect of European and North American poultry housing design and manure management on ammonia emission factors.

Ammonia (NH3) is a major environmental pollutant, responsible for approximately 50% of the PM2.5 pollution in Europe, contributing to eutrophication and acidification. Approximately 15% and 30% of NH3 is emitted from poultry production systems in Europe and North America, respectively. Therefore, it is important to understand the factors affecting NH3 emission factor (NH3 EF) from poultry production systems. In this study, we analysed the DATAMAN database to identify and quantify NH3 EF for different poultry housing systems. The data was classified into four production systems, including broiler production and layer production in North America and Europe· NH3 EF were calculated for these systems. Results showed that the NH3 EF from Europe-based layer production system was lower (52.7%) than North America-based layer production system; the difference was statistically significant (p = 0.0483). Similarly, the NH3 EF for broiler production systems in Europe was 43% lower than that for North American systems (p = 0.0084). The effect of litter management systems on NH3 EF was not significant (p = 0.387). However, the NH3 EF for European-based new litter system (where the litter is removed after every flock) was 40% lower than North American-based built-up litter system (where several flocks are reared on the same litter). In this study, the EF from studies published after 2010 was 54% lower than those from studies published before 2010 (p = 0.007), probably due to improved poultry production systems. Further emission research on newer, improved production systems is required to accurately calculate NH3 EF which is highly needed to improve the emission inventorying of modern poultry houses.