Ammonia and Methane Emission Factors from Cattle Operations Expressed as Losses of Dietary Nutrients or Energy (original) (raw)

Effect of changes in management practices and animal performance on ammonia emissions from Canadian beef production in 1981 as compared with 2011

Canadian Journal of Animal Science, 2018

The present study compared ammonia (NH3) emissions from Canadian beef production in 1981–2011. Temporal and regional differences in cattle categories, feed types and management systems, average daily gains, carcass weights, and manure handling practices were considered. A scenario-based sensitivity analysis in 2011 estimated the impact of substituting corn dried distillers’ grains with solubles (DDGS) for grain in feedlot diets. On average, 22% of the total nitrogen (N) intake was lost as ammoniacal nitrogen (NH3-N) in both years. Manure emission sources were consistent across years, averaging 12%, 40%, 28%, and 21% for grazing, confinement, storage, and land spreading, respectively. Emissions per animal in 1981 and 2011 were 16.0 and 18.4 kg NH3 animal−1 yr−1, respectively. On an intensity basis, kilogram of NH3 emitted per kilogram of beef decreased 20%, from 0.17 in 1981 to 0.14 in 2011. This reduction was attributed to increases in reproductive efficiency, average daily gain and...