Farm-animal welfare is determined by interacting biological, environmental, management, and social conditions, yet these determinants are commonly evaluated in separate evidence streams. This umbrella review synthesizes review-level evidence concerning nutrition, housing, handling and human interaction, environmental enrichment, social conditions, and painful management procedures, with emphasis on how domain interactions alter welfare interpretation. Eligible evidence comprised peer-reviewed review-level publications relevant to farm-animal welfare and methodological sources required for transparent umbrella-review conduct. Review selection, extraction, methodological appraisal, primary-study overlap assessment, and narrative synthesis were designed to preserve species, production-system, developmental-stage, outcome, and measurement boundaries. Numerical retrieval and selection totals are not reported because reproducible export-level counts were unavailable; no counts were reconstructed retrospectively. The review-level evidence indicates that welfare cannot be inferred reliably from a single resource or management characteristic. Nutritional adequacy may coexist with hunger-related behaviour or difficult transitions; housing effects depend on design and management; social contact can alter behavioural development and stress responses; enrichment requires biological relevance and sustained engagement; human-animal relationships can modify fear and interaction; and painful procedures remain procedure-, time-, and analgesia-dependent. The synthesis therefore treats welfare as a conditional configuration of interacting determinants rather than an additive checklist. A proposed cross-domain interpretation architecture emphasizes animal-based outcomes, temporal change, biological constraints, determinant interactions, and uncertainty. Major limitations include uneven species coverage, methodological heterogeneity, overlapping primary evidence, inconsistent outcome definitions, and incomplete reproducibility of selection counts. The findings support multidomain welfare assessment while cautioning against universal prescriptions or causal interpretations unsupported by the underlying reviews.
