The carbon intensity (CI) of co-products fed to beef cattle in the Northern Plains.

The beef production chain accounts for about 40% of world livestock greenhouse gas (GHG) emissions, with feed production representing a substantial component of livestock's carbon footprint. Two important components of livestock rations in the United States are co-products from grain processing: soybean meal (SBM) from soybean crushing, and distillers grains and solubles (DGS) from corn ethanol production. In response to interest in low-carbon beef production, this study estimates the likely carbon intensity (CI) scores of these two co-product feeds, using two life-cycle emissions packages available for use by producers and others. For feedstuffs produced in the Northern Plains we find expected CI estimates of 0.196-0.385 kg CO₂e kg-1 of dry matter for DGS and 0.330-0.456 kg CO₂e kg-1 of dry matter for SBM. The analysis reveals that expected co-product CIs for a given product and model vary by 15%-19% across subregions in which the crop was grown, and that CI of co-products from irrigated crops in this region are about 10% lower than those from non-irrigated crops. These results suggest that beef producers may find opportunities to reduce their product CI by choosing among available supplies of distillers grains and soybean meal.