96-1 Greenhouse Gas Emissions from a Beef Cattle Feedlot.
Beef cattle emit large amounts of the greenhouse gas (GHG) CH4 and N2O, as well as NH3 that contributes to N2O emission when deposited to land. A short-term campaign was conducted at a beef cattle feedlot in Victoria, Australia, to quantify CH4, N2O and NH3 emissions from the pens, manure stockpile and surface run-off pond. Open-path concentration sensors were used with an inverse-dispersion technique to estimate emissions. Daily average emissions of CH4, N2O and NH3 were 132, 0 and 117 g animal-1 d-1 from the cattle pens, and 22, 2 and 9 g animal-1 d-1 from the manure stockpile. Emissions of CH4 and NH3 from the runoff pond were small. The CH4 yield from the cattle pens was 13 g kg-1 (dry matter intake basis; DMI), and the feedlot NH3-N emission was 48% of fed N. Extrapolating these results to the feedlot population of cattle across Australia would mean that feedlots contribute approximately 2% of the national feedlots emissions, with 75% of total GHG emissions from cattle pen.