Sow Welfare: Science and Housing Systems

Key Welfare Considerations

• Pregnant sows in conventional individual stalls cannot turn around — causing severe welfare restriction of natural behaviour.
• Sow stalls were banned in the UK in 1999 and the EU in 2013 — remaining legal in the US and elsewhere.
• Group housing systems allow social interaction, exercise, and behavioural expression welfare improvements.
• Group housing welfare challenges include aggression around feeding, mixing injuries, and body condition variation.
• Electronic sow feeding (ESF) systems manage individual feed allocation in groups reducing welfare competition.
• Floor feeding in group systems without ESF causes welfare aggression and body condition inequality.
• Stable sow groups formed at weaning and not remixed experience lower welfare aggression than dynamic groups.
• Farrowing crates prevent sow movement at farrowing — welfare benefits for piglet survival conflict with sow welfare.
• Free-farrowing systems allow sow movement and nest-building welfare behaviour expression.
• Research shows free-farrowing systems can achieve comparable piglet mortality to crates with management investment.
• Loose farrowing pens with crate option available to sow respect welfare preference and reduce intervention.
• Sow body condition monitoring at weaning identifies welfare nutritional deficiencies from previous lactation.
• Lameness in sows is a significant welfare problem — concrete flooring contributes to joint and foot welfare issues.
• Rubber matting in sow housing areas reduces lameness welfare impact and increases lying time.
• Tail biting and ear biting in group sows indicate welfare environmental deficiency requiring investigation.