Title: Results of the air emission research study Authors
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 12, 2013
Publication Date: November 21, 2013
Citation: Cortus, E.L., Spiehs, M.J. 2013. Results of the air emission research study. Proceedings of the Beef Facility Conference, November 21, 2013, Sioux Falls, SD. Iowa State University AEP 1022. p. 5-9. Online available. https://store.extension.iastate.edu/Product/Beef-Facilities-Conference-Proceedings. Interpretive Summary: Confined cattle facilities are an increasingly common housing system in the Northern Great Plains region. Many of these facilities add organic bedding material to the pens once or twice per week, potentially causing fine dust particles to be emitted from the facility. However, these dust concentrations and other gas emissions from these facilities have not been evaluated. The aim of this study was to determine air quality in deep-bedded monoslope facilities housing beef cattle and to determine if there are management factors that may influence the air quality. Two regulated gases (ammonia and hydrogen sulfide) and dust were measured at four facilities. Two facilities removed manure and bedding weekly (called a Scrape barn) and two facilities allowed a pack of manure and bedding to accumulate in the pen (called a Pack barn), while cleaning the area around the pack weekly. The concentration of hydrogen sulfide increased as the air temperature increased in both Scrape and Pack barns but the increase was greater and more variable in Pack barns. Dust concentrations in Scrape and Pack barns during hours of routine operation are substantially lower than open feedlots. The dust concentration in Pack barns are slightly higher than open feedlots when producers were adding fresh bedding, but these events are short-lived and dust concentrations quickly return to baseline levels. To improve air quality inside monoslope facilities, beef producers may consider ways to remove manure more frequently or increase air flow through the barn.
Technical Abstract: Air quality was monitored in beef mono-slope barns. The objectives of the study were 1) to gather baseline data for the levels of gas emissions and particulate matter from beef mono-slope facilities, 2) evaluate the effect of two different manure handling systems on air quality, and 3) provide information about building and management practices that may reduce gas and particulate matter emissions. Gases from four mono-slope beef finishing facilities were measured in each barn during month-long monitoring periods during fall, winter, spring and summer over a two-year time span. Two barns used a Scrape system in which all bedding and manure were removed weekly and replaced with fresh bedding. Two barns used a Pack system in which only the bunk aprons and edges surrounding the pack were scraped weekly. Ammonia (NH3), hydrogen sulfide (H2S), and environmental data (air temperature, speed, and relative humidity) were measured in each barn over a two year time span. Particulate matter (PM) concentrations in one Pack barn was measured over two 5-day periods to compare routine operation and bedding events. In the Scrape barns, PM concentrations were measured at least twice during each monitoring period between August 2010 and December 2011. The Scrape barn PM data was used to determine the relationship of PM concentration with environmental and management factors. Average NH3 concentrations ranged from 2100 to 3800 and average H2S concentrations ranged from 23 to 103 ppb. Gas concentration changed throughout the day in response to animal activity and temperature. There was a significant increase in H2S concentration with increasing temperature in both Scrape and Pack barns, but the increase was greater and more variable in Pack barns. Particulate matter concentrations in Scrape and Pack barns during hours of routine operation are substantially lower than open feedlots. Average total PM concentrations were 59 and 702 µg/m3, for routine operation and bedding events, respectively. The PM concentrations in Pack barns are slightly higher than open feedlots during bedding events, but these events are short-lived and PM concentrations quickly return to baseline levels. To improve air quality inside monoslope facilities, beef producers may consider ways to remove manure more frequently or increase air flow through the barn.