Environmental impact and adaptation study of pig farming relocation in China

Under the guidance of agri-food and water resources policies, some pig farms in China have gradually shifted their production from the Constrained Zone with a dense population and sensitive environment to the Potential Zone with richer feed resources and large environmental capacity. To evaluate whether the relocation is consistent with sustainable consumption and production, the study took the Key Zone with large pig production and supply as comparison object, constructed a life cycle assessment (LCA) model of pig production in the Constrained, Key, and Potential zones. The environmental impacts caused by the production of 1 ton of pork in these zones were 24.67 PE, 20.11 PE, and 20.44 PE, respectively, indicating that raising pigs in the Key and Potential zones is more environment-friendly than that in the Constrained Zone. Therefore, the relocation of pig farms from the Constrained Zone to the Potential Zone was found to be suitable for protecting water resources and environmental quality. Additionally, the Key Zone can maintain and even increase the existing breeding scale without transferring farms to the Potential Zone. LCA results showed that pork production has significant impacts on cancer risk, freshwater ecotoxicity, terrestrial eutrophication, and terrestrial acidification. Additionally, a majority of the environmental impacts result from crop and pig production, which are key processes in improving the pork supply chain. The soybean import ratio and feed conversion ratio are important indicators for reducing environmental impacts. Statement of novelty: To evaluate whether pig farm relocation in China is consistent with sustainable consumption and production, a life cycle assessment (LCA) model of pig production in the Constrained, Key, and Potential zones was conducted. According to the results, relocating farms from the Constrained Zone to the Key and Potential zones was more environment-friendly. The Key Zone can maintain and even increase the existing breeding scale without transferring the farms to the Potential Zone. LCA results showed that the majority of the environmental impacts result from crop and pig production. Thus, further guidance and education can be provided to farmers in the Potential and Key zones. In addition, sensitivity analysis indicated that large-scale farms should reduce the feed conversion ratio to reduce environmental impacts.