Environmental footprint assessment of representative swine diets in the USA

Abstract

Abstract. Swine production have a large impact on environment in terms of land use, water consumption and climate change. The objective of this study is to determine and compare the environmental footprints of representative US swine diets through life cycle assessment (LCA). Swine producers are looking for alternative diets to reduce feed cost as well as environmental impact. However, data on environmental footprints of various feed ingredients are limited, not well organized and mostly depend on European studies. Diets from the survey results included representative diets Corn-Soybean meal (SBM), Corn-SBM-low DDGS (Distillers Dried Grain with Solubles), Corn-SBM-high DDGS, Corn-SBM-DDGS-bakery-midds and Milo-SBM. The goal of this study is to provide solid information that can assist US swine producers in their selection of alternative diets with consideration of environmental impacts. We have conducted a systematic literature review on existing LCA studies and presented the most up-to-date data from literature as well as USDA-NASS (U.S. Department of Agriculture), and LCA software SimaPro-version 8.5.2.0. Two different scenarios were considered, with scenario 1 using data for 2017/2018 and scenario 2 using projected data for 2023. Sensitivity analysis was performed to ensure the reliability of the LCA outcome. Comparison between different feed ingredients was discussed with a view for sustainable diet formulation. Results showed that the environmental impacts of 1 kg of diet ranges between 1.36-2.47 kg CO2 eq. GWP, 1.58-3.43 gal water, 0.023-0.069 m2a crop eq land use and 0.002-0.003 kg oil eq fossil resources per kg live weight swine production. Among all the diets co-products constituted diet Corn-SBM-DDGS-Bakery-Middlings exhibited the lowest impacts for US swine production.