A Cradle to Farm Gate Life Cycle Analysis of Land Use in U.S. Pork Production

The goal of this study was to conduct a detailed Life Cycle Assessment (LCA) of the U.S. live swine production supply chain to quantify land use requirements and to assess the impact associated with various ration compositions. The functional unit was defined as one kilogram (2.2 pounds) of live swine at the farm gate, ready for transport to the abattoir. This assessment focused on the three highest producing USDA regions, which encompassed the Midwest (Regions 5 and 7) and the Southeast (Region 4), representing 86% of U.S. market hog production. First, a literature review was conducted to summarize the most current information and knowledge regarding the status of land use accounting in agriculture and livestock production. The literature review identified work reported by other researchers and organizations, nationally and internationally, and was used to guide the methods and help create the life cycle inventory (LCI) for the detailed LCA. The study showed that the average land occupation required to produce 1 kg of live swine weight (LW) in the U.S. was 4.22 m2a. This result is based on a feed ration that was intended to represent a typical U.S. swine ration, referred to as the baseline. Regional results were calculated assuming corn, DDGs, and soybean meal were sourced within each production region, excluding Region 4, which assumed 70% of the feed was a commodity average. Swine in Region 4 had the highest land occupation at 4.59 m2a/kg LW, followed by 4.13 m2a/kg LW in Region 5 and 4.11 m2a/kg LW in Region 7. In addition to the baseline diet, six diet scenarios were modeled to assess the impact of ration composition. A linear programming model was used to construct four ration manipulation strategies intended to lower cost, carbon footprint, water use, and land use. Two more rations were included to assess the increased use of synthetic amino acids. All scenario diets showed impact reductions from the baseline in one or more categories ranging from 2% to 73%. However, each diet also resulted in greater impacts for at least one of the other categories