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Broiler litter ammonia emissions near sidewalls, feeders, and waterers

Miles, D. M., Brooks, J. P., McLaughlin, M. R., Rowe, D. E.
Poultry science 2013 v.92 no.7 pp. 1693
air flow, air quality, ammonia, animal drinkers, animal feeders, atmosphere, boric acid, broiler chickens, equations, flocks, gas emissions, pH, poultry housing, poultry manure, rice hulls, titration, water content
Ammonia (NH ₃) volatilized from broiler litter diminishes indoor air quality, which can potentially decrease bird productivity. Emissions of NH ₃ exhausted from broiler houses pose environmental concerns for ecosystem biodiversity, aquatic nutrient enrichment, and particulate formation in the atmosphere. Research was conducted sampling litter (rice hull base) in 3 tunnel-ventilated commercial broiler houses during wk 3 (mid-growout) of 6 flocks. The purpose was to assess NH ₃ generated near the sidewalls, waterers, and feeders. Litter samples (100 g) were placed in chambers receiving constant air flow. Boric acid (H ₃BO ₃) titration each 24 h for 4 d was used to determine NH ₃ volatilized from the samples. Litter located near waterers emitted the most cumulative NH ₃ (approximately 12.3 mg of N•kg of litter ⁻¹•h ⁻¹) with less NH ₃ associated with feeders and sidewalls (2.9 to 7.6 mg of N•kg of litter ⁻¹•h ⁻¹). Moisture content of litter samples was greatest at waterers (45%) followed by sidewalls (26%) and feeders (20%). In addition, litter pH at the sidewalls and feeders could be predicted by linear equations associated with the number of flocks on the litter. At the waterers, litter pH was differentiated based on the half of house where higher litter pH existed in the nonbrood half (8.55 vs. 8.13). The results indicate that controlling NH ₃ near watering lines to a level consistent with feeding lines and near the house wall could reduce NH ₃ generated by 38 to 77%. These findings support efforts for NH ₃ control at mid-growout, especially considering zone litter treatments near waterers and appropriate attention to waterer management.