Pig welfare assessment has evolved from resource-based to outcome-based measures. Understanding how welfare is measured helps advocates and producers identify meaningful improvements.
The evolution from input-based to outcome-based welfare assessment represents a major conceptual advance in farm animal welfare science. Rather than checking whether farms have enrichment items or meet space thresholds, outcome measures ask whether pigs are actually experiencing good welfare: are they free from injuries, fear, and disease, and are they engaging in positive behaviors? This shift makes gaming of welfare standards harder and provides more reliable information about actual animal experience. Slaughterhouse-based welfare assessment is particularly valuable as it provides population-level data from large numbers of animals processed from specific farms, enabling targeted interventions. Investment in developing validated, practical positive welfare indicators for pigs remains a research priority that would significantly strengthen welfare assessment frameworks.