Life cycle assessment in cattle farming systems: a review of approaches, goals and scopes

Life Cycle Assessment (LCA) evaluates the environmental impacts over the life-cycle of a product. Although its applications on cattle systems have progressed remarkably, less is known about how LCA approaches, goals and scopes have evolved. For this purpose, we reviewed 239 LCA studies on European whole-farm cattle systems from 2010 to 2024. Attributional LCA dominated (94%) over consequential and territorial LCA. Thirty-five per cent of studies described a system, 28% compared different systems, and 37% evaluated mitigation options, therefore focusing more on present-day situations than on improvements. Use of on-farm collected data increased between 2010–2024, but mitigation-assessment studies relied more on modelled-farm data. Most studies used a few impact categories (IC) – global warming (GWP), acidification (AP), eutrophication (EP) potentials – and one (product-based) functional unit (FU), and very few explored relations between ICs and FUs. Therefore, we analysed such relations in 75 dairy farms from grassland-based, mixed and confined systems. The GWP, AP and EP were highly and positively correlated but poorly related to energy and land use. Impacts per unit of milk and unit of land were unrelated. They ranked differently between systems and farms, with confined farms showing similar impacts per unit of milk but higher per unit of area than grassland-based farms. Future LCA studies should focus on comparative aims, on-farm collected data, and multiple ICs and FUs to capture the variability of all the cattle systems’ impacts and the synergies/trade-offs between systems and farms. Non-attributional approaches are needed to consider impacts on whole food systems