Assessment of the ammonia emissions from conventional, mechanically ventilated broiler houses in Northern Ireland

Ammonia (NH3) is an important pollutant, with serious negative environmental effects. With targets to reduce the total emissions at a United Kingdom level by 2030, it is important to quantify the emissions from contributing sectors to understand the current state for future mitigation strategies. The objective of this work was to establish an updated NH3 emission factor for broiler production in Northern Ireland. NH3 was measured on two identical broiler houses following the principles of the VERA 2.0 protocol across one year's production which encompassed at least six continuous measurement periods of a minimum of 24 h. The NH3 emissions calculated during this work did not statistically differ between the site (P = 0.275) or house (P = 0.631). NH3 emissions increased with progressing bird age (P < 0.001). NH3 emissions were not influenced by outside environmental conditions. The current study updated the NH3 emission factor for mechanically ventilated, confined broiler systems in Northern Ireland to 0.024 kg/bird place/year, 10.1 %TAN or 42.6 g/LU/d which is 29% lower in comparison to the previous the figure of 0.034 kg/bird place/year reported by The UK Ammonia Inventory.