Reducing the environmental impact of pig production using organic acid- preserved cereal grains: A life cycle assessment

Feed is a major cost and environmental hotspot in pig production, driven by the resource-intensive nature of grain cultivation, processing, preservation, and transport. This study compared the environmental impacts of conventional grain drying at harvest with organic acid (OA) preservation of wheat and barley, and evaluated the effects of feeding these grains to sows and their progeny under commercial conditions. A cradle-to-farm-gate life cycle assessment (LCA) was conducted using primary data, encompassing crop production, grain preservation (drying or OA preservation), feed manufacture, transport, and animal rearing, while excluding manure management. Four dietary treatments were evaluated based on the grain used in sow and progeny diets: (1) dried (sow)-dried (progeny), (2) dried-preserved, (3) preserved-dried, and (4) preserved-preserved. At the grain store gate, OA preservation reduced the global warming, acidification, and eutrophication impacts of wheat by 18%, 6%, and 5%, and of barley by 15%, 5%, and 5% respectively (P<0.001), primarily due to the elimination of fossil fuel use during drying. This resulted in reductions in fossil fuel depletion of 81% for wheat and 74% for barley (P<0.001). At the pig production level, replacing dried grain with preserved grain in sow diets during late gestation and lactation reduced progeny impacts by 3–4% across all impact categories, while direct inclusion of preserved grain in progeny diets achieved larger reductions of 7–8% (P<0.001). The preserved-preserved system delivered the greatest overall reductions relative to the dried-dried control, decreasing global warming by 11%, acidification by 12%, and eutrophication by 12%. Given the urgency for agriculture to adopt more sustainable practices, these findings demonstrate that integrating OA-preserved cereals into sow and progeny diets can substantially reduce the environmental footprint of pig production. Commercial-scale implementation and economic assessment are now warranted to support wider adoption of OA preservation within pig supply chains.