Developing valid, comparable welfare metrics across species and production systems is a key challenge for advancing welfare science and policy. Current approaches and their limitations inform better frameworks.
The Five Freedoms framework, developed in 1979, remains influential but has been superseded by more positive frameworks like the Five Domains and the Qualitative Behaviour Assessment. Outcome-based welfare metrics — measuring actual animal states rather than inputs like space allowances — are increasingly preferred. The Welfare Quality project developed multi-criteria assessment tools for several species. Population-level welfare metrics that aggregate individual assessments create policy-relevant data. Standardised international welfare metrics would enable comparison across countries and production systems, driving competitive improvement.