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Complex variation in gas emissions from animal facilities has been shown in recent research reports. Uncertainties in these emission estimates are driving research activities concerning different animal species across the globe. Greenhouse gas (N2O and CO2) and NH3 concentrations were measured in a modern, tunnel-ventilated, commercial broiler house in Mississippi during five flocks (spanning approximately 1 yr). These were flocks 9 through 13 on reused pine shavings litter, representing litter reuse beyond 2 yr. Gas concentrations obtained from a photoacoustic multigas analyzer were coupled with ventilation measurements of air flow through the house to develop NH3 and N2O emission rates. Ammonia emission during a flock (43 d) averaged approximately 14.8 ± 9.8 kg d-1 in the commercial house (equivalent to 23.5 g bird marketed-1 or 0.54 g bird-1 d-1). Nitrous oxide emission averaged 2.3 ± 1.7 kg d-1 in the house (equivalent to 3.64 g bird marketed-1 or 0.085 g bird-1 d-1). Emission rates increased with time from Day 1 to Day 43 and reached average values on Day 23 and 24 for NH3 and N2O. Even with extended litter reuse, estimates of NH3 emissions from the broiler house agree well with recently published research that reused litter in eight or fewer flocks. This is important information for farmers who may not be able to afford to replace the litter with fresh bedding material annually. [ABSTRACT FROM AUTHOR]