WP2
WP2 Evaluation of Circularity in Cattle Farming Systems in Hesse using
Life Cycle Assessment
Research |
ContextAgriculture, and particularly livestock farming systems, are situated in a trade-off between a globally increasing demand for animal-based food such as meat, eggs, and milk on the one hand, and growing concerns about the negative environmental impacts of livestock production on the other hand (Calvin et al., 2023; Muscat et al., 2021; OECD & FAO, 2024). Intensive systems with higher yields generally perform better from a climate perspective (Zehetmeier et al., 2020). However, these systems are often highly dependent on feed derived from arable land or external feed resources, thereby competing with direct human food production. Circular cattle farming systems could reduce feed-food competition by utilizing by-products from the food industry, permanent grassland, and crop rotation side products such as clover grass (Muscat et al., 2021; Van Zanten et al., 2019). Furthermore, nutrients would largely be recycled, ecosystem services provided, and additional animal-based food for human consumption produced under high animal welfare standards (Van Zanten et al., 2018, 2019). MethodologyTo quantify and evaluate this approach, primary data were collected from approximately 40 cattle farms in Hesse. These data are used to calculate farm-specific life cycle assessments (LCA) using the software openLCA. Many LCA studies compare virtual farms due to the time-intensive nature of primary data collection. Our objective is to provide a representative overview of sustainability in cattle farming in Hesse based on real farm primary data. In a second step, the assessments will be adjusted to comprehensively represent and evaluate circularity aspects in cattle farming systems. This can be achieved either by selecting alternative allocation methods that account for ecosystem services (Robert Kiefer et al., 2015), or by implementing new impact categories that reflect circularity. The assessment is conducted from cradle to farm gate using fat- and protein-corrected milk (FPCM) [kg], meat [kg live weight], area [ha], and human edible protein (HEP) [kg] as functional units. To achieve this, raw data are processed and integrated into a database system (Access), corresponding to the compilation of the life cycle inventory of each farm. Direct emissions are calculated using the LfL climate check tool. Subsequently, the compiled data are transferred via an interface to openLCA, where they are linked with background data (from the AGRIBALYSE and ecoinvent databases) and the impact assessment is carried out. Relevant impact categories for cattle farming systems include global warming potential (kg CO2 eq.), land use (m²·year crop eq.), water consumption (m³), fossil resource use (kg oil eq.), freshwater eutrophication (kg P eq.), marine eutrophication (kg N eq.), terrestrial acidification (kg SO2 eq.), and toxicity (kg 1,4-DCB eq.). A subsequent sensitivity analysis will assess the plausibility of the life cycle assessment and the underlying data. It also identifies key parameters that significantly influence specific impact categories. These parameters can serve as leverage points for reducing emissions at the farm level. |
Example of a LCA process chart
