Ammonia emissions from kentucky broiler houses during winter, spring and summer

A multi-state, multi-disciplinary project is developing a comprehensive database of ammonia (NH ₃) emission rates (ER) from US poultry facilities. The influence of common management strategies and practical means of reducing NH ₃ emissions are under study. The measurement of ER during winter, spring and summer from 4 broiler houses with re-used ('built-up') litter is described in this paper. Ammonia concentrations were determined using electrochemical sensors configured with a purging system; ventilation rate was accurately estimated by measuring building static pressure and ventilation fans runtime using individual fan calibrations. Mean ER (2 sequential days, 4 houses) ranged from 0.14 to 1.92 g NH ₃/bird/d. Bird age during ER measurement ranged from 1 to 56 days old. Regressions of ER v. bird age and ventilation rate are presented. There was high variability for ER among the houses, even for houses on the same farm (6-75% CV). Consecutive day-to-day variability was substantially less than house-to-house variability for the same time period, and appeared related to ventilation rate changes.