Farmed Pig Welfare Metrics in Practice

Practical pig welfare assessment using animal-based indicators provides a more reliable picture of actual welfare than compliance with housing standards alone.

Key Facts

The Welfare Quality Pig Protocol assesses 12 welfare criteria through animal-based indicators observed on farm
Animal-based indicators include: tail lesion scores, skin lesion scores, lameness scores, body condition, behavioral indicators, and housing observations
Interobserver reliability for welfare scoring is moderate to good for most indicators when assessors are trained to a common standard
Tail lesion scoring at slaughterline provides a population-level welfare indicator that cannot be fabricated by farm preparation for audit visits
Skin lesion scoring reveals fighting injuries that indicate inadequate space or social management that housing measurements alone would miss
Behavioral indicators including positive social behavior and play provide positive welfare information alongside negative indicators
The Pig Welfare Outcome (PWO) tool developed in the UK provides a simpler field-usable welfare assessment for routine monitoring
Regular on-farm monitoring using standardized tools produces welfare improvement through feedback and benchmarking effects

Welfare Considerations

Practical pig welfare assessment using animal-based indicators represents the most reliable available method for determining whether pigs are actually experiencing good welfare rather than simply living in compliant housing. A farm can meet all housing specifications while managing social mixing poorly, providing inadequate enrichment, and generating high rates of lameness and tail biting. Animal-based indicators detect these management failures that input measurements miss. The behavioral and lesion-based welfare indicators validated through decades of welfare science research provide assessors with tools to evaluate actual animal experience rather than proxies. Slaughterline welfare assessment — examining animals after slaughter for welfare-relevant lesions — provides population-level welfare data that auditors cannot influence by farm preparation, making it particularly valuable for accountability purposes.

What You Can Do

Support certification programs that use validated animal-based welfare indicators in their farm audit protocols
Advocate for regulatory requirements to use welfare outcome measures alongside housing specifications in welfare inspections
Support research into practical, low-cost welfare monitoring tools that farmers can use for routine self-assessment
Engage with supermarket and food service procurement standards to ensure they require animal-based welfare measurement