Attributing Farm-to-Slaughter Emissions to Hides: Evidence from Beef Supply Chains

To ensure transparent Life Cycle Assessment (LCA), climate impacts from cattle production must be consistently allocated among meat, milk and raw hides. This review examines allocation boundaries, compares physical and economic methods, and evaluates the upstream burden attributable to hides using extensive data from the Italian beef sector. Three hypotheses were tested: that hides, as marketable co-products, bear a non-zero share of upstream emissions (H1); that the burden assigned by economic allocation is lower than that assigned by physical (mass-based) allocation (H2); that allocation shares vary over time according to hide/meat price ratios (H3). The results from large-scale Italian datasets confirmed all three hypotheses. Physical allocation attributed an average of 5.9% of live weight to hides, whereas economic allocation assigned an average of 2.7% in 2023, decreasing over the historical price series. Consistent with available inventories, the upstream carbon footprint of raw hides was found to range from 1.63 kg CO2e/kg (economic allocation) to 3.55 kg CO2e/kg (physical allocation) when GWP100 was used. These findings demonstrate that neglecting co-product allocation leads to the systematic overestimation of the environmental impact of meat and the underestimation of the environmental impact of leather. Overall, economic allocation is the most appropriate and policy-aligned approach to hide accounting, reflecting market value and reducing methodological bias in beef-chain life cycle assessments (LCAs).