159-3 Greenhouse Gas Emissions From Beef Cattle Overwintering Systems On the Canadian Prairies.



Monday, October 17, 2011: 8:35 AM
Henry Gonzalez Convention Center, Room 210A, Concourse Level

Gwendolyn Donohoe1, Kim Ominski2, Mario Tenuta1 and Donald Flaten1, (1)Department of Soil Science, University of Manitoba, Winnipeg, MB, Canada
(2)Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada
Beef cattle producers on the Canadian prairies have traditionally overwintered cows using intensive management practices, including confinement of cows in dry-lots. In attempts to reduce overwintering costs, producers have begun to utilize extensive overwintering systems including swath, bale or stockpiled-forage grazing. However, little information is available on the environmental implications of these extensive overwintering systems, particularly in terms of greenhouse gas (GHG) emissions. The University of Manitoba is conducting a multidisciplinary research program to examine such beef cattle overwintering systems, including measurements of enteric and soil GHG’s. Deposition of feces and urine by one cow on April 20th and monitored through to September, 2009, resulted in combined nitrous oxide (N2O) and CH4 emissions of 257 and 27 g CO2 equivalent m-2, when fed a forage-based diet with and without DDGS (dried distiller’s grains with soluble) supplementation, respectively. Interestingly, DDGS supplementation of the forage-based diet had no significant effect on N2O or CH4 emission from patches of simulated bedding pack, which was composed of a mixture of feces, urine, and straw, with feces and urine added at the ratio of feces to urine produced. Research is ongoing to examine soil GHG emissions from feces and urine patches, as well as enteric methane emissions in a bale grazing system compared to a feedlot system overwinter. This systems-based research project will provide information to producers such that they can mitigate GHG emissions from livestock production, as well as policy makers as they seek to provide accurate information for national accounting purposes.
See more from this Division: S11 Soils & Environmental Quality
See more from this Session: Emissions From Confined Animal Feeding Operations