Air Quality Measurements at a Laying Hen House: Ammonia Concentrations and Emissions

Ammonia emissions were measured for six months at a modern 250,000-hen high-rise egg laying house using the chemiluminescence method along with multi-point extractive gas sampling. The ammonia analyzer was sequenced through twelve sampling locations including nine exhaust fans every two hours and calibrated at least weekly with certified calibration gases. Fan operation was monitored along with building static pressure. The average daily means of NH3 concentrations were 2.4, 16.1, and 43.3 mg m for inlet, cage, and exhaust air, respectively, and were much higher during the colder months than then warmer months. The net NH3 emission rate was 387±25 kg d or 509±33 g per day per 500 kg live mass. Relatively lower emission rates were measured in the warmer months even though the ventilations were higher. The NH3 concentration was also found inversely proportional to inlet temperature, exhaust temperature, and ventilation rate. The ammonia concentration and emission data collected in this test is the most comprehensive study of a single laying house to date.