Ammonia Emission from a Large Mechanically‐Ventilated Swine Building during Warm Weather

Abstract

Abstract Ammonia (NH 3 ) emission from a grow‐finish swine ( Sus scrofa ) building with an underfloor manure storage pit was evaluated during warm weather from 26 June to 25 September. Average daily mean (ADM, covering all measurement days) outdoor temperature was 21.8°C. Ammonia concentrations, ventilation rates, and temperatures were continuously measured or recorded and 88 d of reliable data were obtained. Air samples were taken at wall and pit exhaust fans and in the pit headspace. The NH 3 concentrations were monitored on‐site with a chemiluminescence NH 3 analyzer. Ventilation rates were calculated based on operation of five wall fans, four pit fans, and the fan static pressure. The NH 3 emission rates were calculated by multiplying simultaneously measured NH 3 concentrations and ventilation rates of wall and pit exhaust fans. The ADM of building NH 3 concentration (mean concentration of all sampling locations) was 3.9 mg m −1 . The ADM building NH, emission (sum of the emissions from all ventilation fans) was 11.2 kg d −1 , equivalent to 145 g d −1 per AU (animal unit = 500 kg animal weight). The ADM emission per AU was higher than other reported values, probably due to warmer temperatures and higher ventilation rates. The building NH 3 concentrations were inversely proportional to the indoor temperatures ( r = −0.66) and ventilation rates ( r = −0.59) and correlated well to total pig weight ( r = 0.49). The building NH 3 emission rates were correlated to total pig weights ( r = 0.52) and ventilation rates ( r = 0.41) and were not well correlated to indoor temperatures ( r = 0.12).