Greenhouse Gas Emissions from a Beef Cattle Feedlot.

Abstract

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.