Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/10/2013
Publication Date: 3/26/2013
Citation: Miller, D.N., Spiehs, M.J., Woodbury, B.L. 2013. Effect of feeding distiller’s grains on reduced sulfur emissions. In: Waste to Worth: Spreading Science and Solutions, April 1-5, 2013, Denver, Colorado. Available: http://www.extension.org/pages/67657/effect-of-feeding-distillers-grains-on-reduced-sulfur-emissions.
Interpretive Summary: Three studies were conducted to examine the effect that feeding ethanol byproduct, wet distiller’s grains plus solubles (WDGS), had on emissions of odorous reduced sulfur compounds. These studies found that the relative emission of reduced sulfur compounds from WDGS manures was substantially higher (4 to 22-fold) compared to standard corn-based rations. The studies also indicate that emissions from the feedlot pen surface, a mixture of aged manure and soil, were also greater (0.3 to 4 fold) when WDGS was fed to cattle at high rates (40% of the diet).
Technical Abstract: Odorous reduced sulfur compounds are produced during manure decomposition and emitted from confined animal feeding operations. Feeding high-sulfur distiller’s byproducts may increase the emission of these compounds. The objectives of a series of feedlot pen studies was to (i) determine if emissions of reduced sulfur compounds from fresh manure and from the feedlot surface where affected if cattle were fed varying levels of distillers byproducts, and (ii) determine the areas within a pen that emit greater amounts of reduced sulfur compounds. Three studies were conducted to evaluate the relative impact of feeding high-sulfur wet distiller’s grain plus solubles (WDGS) to beef cattle. In the first study, beef cattle in sixteen small-scale pens were fed varying amounts (0%, 20%, 40%, and 60%) of WDGS, and the relative emissions of reduced sulfur from fresh feces were measured using a laboratory wind tunnel chamber. The relative emission of reduced sulfur from fresh feces was significantly greater (4 to 22-fold) when 40% (or greater) WDGS. A follow up study in eight production-scale feedlot pens also examined the effect of feeding 0% or 40% WDGS on fresh manure emissions and found that reduced sulfur emissions from WDGS manures were higher than control diets, but the relative emission due to WDGS was lower (only 2 to 4 fold higher for WDGS) compared to the first study. A third study in ten production-scale pens examined emissions from the pen surface when cattle were fed 0% and 40% WDGS diets over two production cycles. In the final study, emissions principally came from the wetter edges of the pen when animal were fed higher levels of WDGS in their diet. Over the six study periods, the relative emissions from WDGS pens ranged from 0.3 to 4-fold higher than a standard ration. Consistent results from these three studies indicate that reduced sulfur emissions increase when animals are fed higher levels of WDGS.