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

A multi-state, multi-disciplinary project is developing a comprehensive database of ammonia (NH3) emission rates (ER) from US poultry facilities. The influence of common management strategies and practical means of reducing NH3 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 NH3/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.