Pig Nesting Behaviour at Farrowing

Nest-building is one of the most strongly motivated pre-farrowing behaviours in sows, and its denial in farrowing crate systems causes significant acute welfare distress.

Key Facts

Wild sow nest-building involves travelling up to 6km to collect nesting materials
Domestic sows show the same nest-building motivation sequence regardless of housing
Sows denied nesting material pace and root restlessly for hours before farrowing
Free farrowing systems with straw show dramatically reduced pre-farrowing stress indicators
Sows with nest-building opportunities have lower farrowing duration and piglet mortality in some studies

Welfare Considerations

Pre-farrowing nesting motivation is one of the most powerful behavioural drives documented in farm animals: sows deprived of nesting material show sustained distress behaviour for up to 12 hours before farrowing, with elevated stress hormones and persistent vacuum nesting attempts. This is a profound welfare harm imposed on every sow in a farrowing crate at every farrowing event. Free farrowing systems that provide straw allow the natural behaviour sequence, reducing acute stress and enabling the sow to exhibit her evolved pre-maternal behaviours.

What You Can Do

Choose pork from free farrowing certified farms
Advocate for a UK ban on farrowing crates based on nesting welfare evidence
Support Compassion in World Farming farrowing reform campaigns
Engage supermarkets on free farrowing requirements in pork supply chains
Reduce pork consumption to accelerate market transition to crate-free farrowing