Title: Effect of bedding material on air quality of bedded manure packs in livestock facilities Authors
Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: July 1, 2012
Publication Date: July 29, 2012
Citation: Spiehs, M.J., Brown-Brandl, T.M., Miller, D.N., Parker, D.B. 2012. Effect of bedding material on air quality of bedded manure packs in livestock facilities. Proceedings of the American Society of Agricultural and Biological Engineers (ASABE) Annual International Meeting, July 29 - August 1, 2012, Dallas, Texas. Paper No. 12-1337890. Interpretive Summary: Livestock producers are faced with increasing pressure to reduce or eliminate odors and gas emissions from their facilities. Ammonia and other volatile organic compounds are targeted for reduction due to their unpleasant odors and potential health effects on humans and animals. Other gases (carbon dioxide, methane, and nitrous oxide) are targeted for reduction because they are greenhouse gases. Many different types of bedding material are used by livestock producers. Differences in chemical and physical characteristics of the bedding materials will influence how well the bedding absorbs urine and feces, how quickly the bedding is decomposed, and ultimately, how the bedding material will affect the air quality of livestock facilities. The objective of this study was to determine changes in air quality when pine wood chips and corn stover were mixed in various ratios (0, 10, 20, 30, 40, 60, 80, and 100% pine wood chips) and used as bedding in lab-scaled bedded manure packs. Ammonia, volatile organic compounds, nitrous oxide, carbon dioxide, and methane were measured in air samples collected from the bedded packs. Concentrations of the odorous volatile organic compounds were used to calculate an odor activity value, which is a relative measurement of the odor potential of the bedding material. The concentration of volatile organic compounds was similar among all bedding treatments, as were the calculated odor activity values. Ammonia concentration increased with increasing inclusion of pine wood chips in the bedding mix. Carbon dioxide, methane, and nitrous oxide concentrations were similar among bedding materials. Results of this study indicate that mixtures of bedding material containing > 60% pine wood chips may increase ammonia emissions, but odorous volatile organic compounds, greenhouse gas production, and odor potential will not be affected by the inclusion of pine wood chips when used as bedding in livestock facilities.
Technical Abstract: Bedding materials may affect air quality in livestock facilities. The objective of this study was to compare headspace concentrations of odorous volatile organic compounds (VOCs), ammonia (NH3), carbon dioxide (CO2),methane (CH4), and nitrous oxide (N2O) when pine wood chips (PC) and corn stover (CS) were mixed in various ratios (0, 10, 20, 30, 40, 60, 80, and 100% PC) and used as bedding in lab-scaled bedded manure packs. Odor activity values (OAV) were calculated using VOC concentration. Air samples were collected from the headspace of the lab-scaled bedded packs weekly for 6 weeks. Concentration of VOC was similar among all bedding treatments (P >/= 0.30), as were the OAV. Ammonia concentration increased linearly with increasing inclusion of PC in the bedding mix (P = 0.002; R2 = 0.5819). Carbon dioxide, CH4, and N2O concentrations were similar among bedding materials (P >/= 0.61) and changed throughout the 6 week study (P < 0.01). Results of this study indicate that mixtures of bedding material containing > 60% PC may increase NH3, but VOC, greenhouse gas production, and odor potential as indicated by OAV will not be affected by the inclusion of PC when used in deep-bedded livestock facilities.