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 PM_2.5 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.