Life Cycle Assessment of a Modern Northern Great Plains U.S. Swine Production Facility

Abstract

A life cycle assessment (LCA) model was developed to determine the environmental impacts associated with a modeled modern Northern Great Plains U.S. swine production facility. This region has experienced significant growth (2.5 million head increase since 1996) and currently accounts for 13% of U.S. swine herd. The LCA model followed a “gate-to-gate” perspective focusing solely on feed manufacturing and swine production facility operations and did not include feedstuff production or abattoir and other postproduction supply chain processes. Model input data were normalized using a head of swine functional unit and were segregated into two operation processes and associated subprocesses: feed manufacturing including electricity use and completed feed transport, and production facility operations including manure handling and storage, enteric emissions, electricity generation and propane production, and water extraction. Four distinct operation scenarios were modeled, including normal operations, use of feed-based antimicrobials, a 50% reduced completed feed transportation distance, and a 30% increased use of renewable energy for all operations. For the normal operations scenario, climate change impacts were predominantly attributed to swine enteric emissions (331.6 kg CO2 eq) and manure storage and handling (53.4 kg CO2 eq), whereas antimicrobial use reduced total climate change impacts by 3.7%. Manure storage and handling resulted in the greatest contribution toward marine eutrophication (0.048 kg N eq) and terrestrial acidification (1.29 kg SO2 eq) impacts, whereas production facility electricity and heating resulted in the greatest terrestrial ecotoxicity (0.00060 kg 1,4-DB eq) and freshwater eutrophication (0.00016 kg P eq) impacts observed. Results from this LCA model provide Northern Great Plains swine producers and environmental practitioners with techniques that can be used to improve swine production efficiencies and identify opportunities for a future carbon-constrained and sustainability-aware marketplace.