Environmental effects of cattle production and the overall sustainability of beef have become national and international concerns. Our objective was to quantify important environmental impacts of beef cattle production throughout the United States. This provides baseline information for evaluating potential benefits of alternative management practices and mitigation strategies for improving the sustainability of beef.
What did we do?
Surveys and visits of farms, ranches and feedlots were conducted throughout seven regions of the United States (Northeast, Southeast, Midwest, Northern Plains, Southern Plains, Northwest and Southwest) to determine common practices and characteristics of cattle production. These data along with other information sources were used to create about 150 representative production systems throughout the country, which were simulated with the Integrated Farm System Model using local soil and climate data. The simulations quantified the performance and environmental impacts of beef cattle production systems within each region. A farm-to-gate life cycle assessment was used to determine resource use and emissions for all production systems including traditional beef breeds and cull animals from the dairy industry. Regional and national totals were determined as the sum of the production system outputs multiplied by the number of cattle represented by each simulated system.
What we have learned?
Average annual greenhouse gas emission related to beef cattle production was determined as 268 ± 29 million tons of carbon dioxide equivalent, which is approximately 3.3% of the reported total U.S. emission. Fossil energy use was 539 ± 50 trillion BTU, which is less than 1% of total U.S. consumption. Non-precipitation water use was 6.2 ± 0.9 trillion gallons, which is on the order of 5% of estimated total fresh water use for the country. Finally, reactive N loss was 1.9 ± 0.15 million ton, which indicates about 15% of the gaseous emissions of reactive N for the nation are related to beef cattle production. Expressed per lb of carcass weight produced, these impacts were 21.3 ± 2.3 lb CO2,e, 21.6 ± 2.0 BTU, 0.155 ± 0.012 lb N and 244 ± 37 gal for carbon, energy, reactive N and water footprints, respectively. Many sources throughout the production system contributed to these footprints (Figure 1). The majority of most environmental impacts was associated with the cow-calf phase of production (Figure 2).
Take-home message: This study is the most detailed, yet comprehensive, study conducted to date that provides baseline measures for the sustainability of U.S. beef.
Future plans
These farm-to-gate values are being combined with sources in packing, processing, distribution, retail, consumption and waste handling to produce a full life cycle assessment of U.S. beef considering additional metrics of environmental and economic impact. Further work is ongoing to complete this full LCA and to more fully assess opportunities for mitigating environmental impacts and improving the sustainability of beef.
Authors
Alan Rotz, USDA-ARS; Senorpe Asem-Hiablie, USDA-ARS; Sara Place, National Cattlemen’s Beef Association; Greg Thoma, University of Arkansas.
Additional information
Information on the Integrated Farm System Model is available in the reference manual:
Rotz, C., Corson, M., Chianese, D., Montes, F., Hafner, S., Bonifacio, H., Coiner, C., 2018. The Integrated Farm System Model, Reference Manual Version 4.4. Agricultural Research Service, USDA. https://www.ars.usda.gov/ARSUserFiles/80700500/Reference%20Manual.pdf.
Further information on the national assessment of the environmental impacts of U.S. cattle production is available in:
Rotz, C. A., S. Asem-Hiablie, S. Place and G. Thoma. 2019. Environmental footprints of beef cattle production in the United States. Agric. Systems 169:1-13.
Acknowledgements
This work was funded in part by The Beef Checkoff and the USDA’s Agricultural Research Service. USDA is an equal opportunity provider and employer.
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