Methane Emissions by Lactating Ewes Grazing Italian Ryegrass

Agriculture contributes 13.5% of global emissions of greenhouse gases (GHG) (IPCC 2007), and about 50% of CH4 and 60% N2O from anthropogenic sources, while livestock contributes an additional 18% of global GHG emissions (FAO, 2006). Among the various sources with a potential negative impact on the environment, methane emissions for which livestock are mainly responsible have been highlighted for the agricultural sector. Studies on means to mitigate these emissions, and understand how integrated crop and livestock production systems may contribute to the reduction of greenhouse gases, are essential for the creation of public policies for environmental preservation. The objective in this study was to evaluate how strategies for grazing management can influence animal production and emission of methane in areas of crop-livestock integration