Comprehensive national assessment on the sustainability of beef production

Abstract Text:

To develop better scientific understanding of the sustainability of beef in the United States, a national assessment is being conducted by the National Cattlemen’s Beef Association, a contractor to the beef checkoff. This includes a life cycle assessment (LCA) of greenhouse gas emissions along with other environmental, social and economic impacts. Assessments are being made for representative cattle operations in each of seven geographic regions to form the national total. Producer surveys and visits are used to characterize region-specific production systems, and the information gathered provides a basis for system simulation and a farm-gate LCA. Assessments have been completed for the Central Plains and Midwestern regions, and are in progress for the western and eastern regions of the country. Results thus far show farm-gate carbon footprints of representative production systems vary from 16 to 28 kg CO₂e/kg of carcass weight (CW) with a mean around 20 kg CO₂e/kg CW. The cow calf operation is the source of 67 to 77% of this footprint and stocker operations contribute up to 18% of the footprint. Thus, depending upon whether cattle are backgrounded on pasture or in a feedlot, the grassland-based portion of the system can contribute 67 to 85% of the farm-gate carbon footprint of finished beef cattle. Enteric methane emission is the source of about 60% of the total greenhouse gas emissions from cow calf and stocker operations and 35% of that from feedlot finishing operations. Nitrous oxide emissions contribute about 20% of the carbon footprint of grazing cattle. Considering post farm gate sources (harvest, retail, restaurant and consumer) the full carbon footprint is about 45 kg CO₂e/kg of consumed beef. Of this total, 58 to 73% can be attributed to emissions from grazing cattle and the inputs required to maintain them. A similar result is found for environmental impacts such as total reactive nitrogen loss where 50 to 70% of the farm-gate footprint is attributed to grazing cattle. Thus to make substantial reductions in the environmental impacts of beef production, our analysis to this point indicates that mitigation strategies are needed to reduce greenhouse gas and nitrogen emissions from grassland systems. This provides a major challenge for beef cattle research because practical technologies or strategies for reducing these emissions are essentially unknown.

Keywords: Beef, Cattle, Carbon footprint