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United States Department of Agriculture

Agricultural Research Service

Research Project: SAFE MANAGEMENT AND USE OF MANURE, BIOSOLIDS AND INDUSTRIAL BYPRODUCTS Title: Litter Ammonia Generation: Moisture Content and Organic vs. Inorganic Bedding Materials

Authors
item Miles, Dana
item Rowe, Dennis -
item Cathcart, T -

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 7, 2011
Publication Date: June 1, 2011
Citation: Miles, D.M., Rowe, D.E., Cathcart, T.C. 2011. Litter ammonia generation: moisture content and organic versus inorganic bedding materials. Poultry Science. 90:1162-1169.

Interpretive Summary: Negative impacts on the environment, bird well-being, and farm worker health indicate the need for abatement strategies for poultry litter NH3 generation. Type of bedding affects many parameters related to poultry production including NH3 losses. Broiler excrement was mixed with pine wood shavings, rice hulls, sand, and vermiculite to create litter samples for assessing NH3 volatilization. Statistical models were generated to predict NH3 loss over time. Cumulative NH3 emitted for each excreta-bedding mixture as well as commercial broiler litter (original bedding: pine wood shavings) were assessed at the original moisture content and two additional gradient moisture increments. At the original moisture content, sand and vermiculite litters generated the most NH3 whereas wood shavings, commercial, and rice hull litters emitted the least NH3. For reducing NH3 emissions, the results support recommendations for using wood shavings and rice hulls, already popular bedding choices in the U. S. and worldwide. In this research, the organic bedding materials generated the least NH3 at the original moisture content when compared to the inorganic materials. For each bedding type, incremental increases in litter moisture content increased NH3 volatilization. Vermiculite was a novel bedding choice that has a high water absorption capacity, but because of high NH3 generation, it is not recommended for further study as broiler bedding material. This research demonstrates expectations for wood shavings, rice hulls, sand, and vermiculite encountering the same inputs. Controlling unnecessary moisture inputs to broiler litter is a key to controlling NH3 emissions.

Technical Abstract: Negative impacts on the environment, bird well-being, and farm worker health indicate the need for abatement strategies for poultry litter NH3 generation. Type of bedding affects many parameters related to poultry production including NH3 losses. Broiler excrement was mixed with pine wood shavings, rice hulls, sand, and vermiculite to create litter samples for assessing NH3 volatilization. Litter samples of uniform volume and surface area were placed in chambers receiving humidified air where the exhaust passed through H3BO3 solution, which trapped NH3 emitted from the litter. Statistical models were generated to predict NH3 loss over time. Cumulative NH3 emitted for each excreta-bedding mixture as well as commercial broiler litter were assessed at the original moisture content and two additional gradient moisture increments. The original bedding material for the commercial litter was pine wood shavings that had been used for two previous flocks. At the original moisture content, sand and vermiculite litters generated the most NH3 whereas wood shavings, commercial, and rice hull litters emitted the least NH3. For reducing NH3 emissions, the results support recommendations for using wood shavings and rice hulls, already popular bedding choices in the U. S. and worldwide. In this research, the organic bedding materials generated the least NH3 at the original moisture content when compared to the inorganic materials. For each bedding type, incremental increases in litter moisture content increased NH3 volatilization. The effects of bedding material on NH3 volatilization at the elevated moisture levels were not clear. Vermiculite was a novel bedding choice that has a high water absorption capacity, but because of high NH3 generation, it is not recommended for further study as broiler bedding material. This research demonstrates expectations for wood shavings, rice hulls, sand, and vermiculite encountering the same inputs. Controlling unnecessary moisture inputs to broiler litter is a key to controlling NH3 emissions.

Last Modified: 12/20/2014
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