Methane Production via Anaerobic Digestion of Feedlot Manure A.K. Watson, G.E. Erickson, S.C. Fernando, T.J. Klopfenstein, A.Schmidt Trial 1 Seven, 1 L anaerobic digesters Cattle Diets: Control WDGS 82.5% DRC 47.5% DRC 5% Molasses 40% WDGS 7.5% Alfalfa 7.5% Alfalfa 5% Supplement 5% Supplement 0.986% Urea Trial 2 Cattle Housing: Open Lot Confinement Manure OM 26% 88% Trial 3 Ten, 45 L anaerobic digesters Cattle Housing: “Pure” manure 80% OM Soil surface of pen 10% OM Stockpiled 20% OM Fresh 25% OM Cement pad 50% OM Trial 1: Effects of cattle diet Trial 2: Effects of cattle housing CONT WDGS SEM P- value CONF FDLT SEM P- value DMD, % 42.7 44.9 1.06 0.05 39.0 19.9 2.79 < 0.01 OMD, % 51.0 52.9 1.14 0.10 46.7 24.8 3.11 < 0.01 Methane, L/d 0.551 0.634 0.05 0.10 0.478 0.229 0.07 < 0.01 Methane, L/g OM fed 0.116 0.137 0.01 0.05 0.103 0.189 0.03 0.01 Trial 1: Effects of cattle diet on microbial communit Eubacteria Archaea CONT WDGS 177 137 87 47 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 -0.5 -0.4 -0.3 -0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 Principal Coordinate Analysis Bacteria-WDGS Bacteria-CONT Archaea-WDGS Archaea-CONT PC1 (23.6% - Bacteria, 53.9% - Archaea) PC2 (15.5% - Bacteria, 14.0% - Archaea) Conclusions Trial 1 • Manure from cattle fed WDGS had increased methane potential compared to corn based CONT • Dietary changes can lead to changes in microbial community that provide opportunities to alter methane production from cattle manure Trial 2 • Open lot manure can be used as anaerobic digester feedstock if ash buildup is avoided Trial 3—In progress • Strategically harvesting manure may enhance methane production from open lot manure and allow the feedlot Cement Pa d Soil surface Introduction Results Variation in Microbial Community Homova Archaea P < 0.001 Eubacte ria P = 0.019 Amova Archaea P < 0.001 Eubacte ria P < 0.001