Pig Farrowing Nest Building: Satisfying a Core Behavioral Need

Nest building before farrowing is one of the most strongly motivated behaviors in sows. Providing materials to satisfy this drive significantly improves welfare in the critical pre-farrowing period.

Key Facts

Sows show intense nest building motivation in the 24 hours before farrowing, rooting and gathering materials
In the wild, sows travel up to 6km to find appropriate nesting materials before farrowing
Denying nesting materials causes measurable behavioral frustration, agitation, and stress indicators
Straw provision allows sows to perform nesting behavior and is associated with calmer farrowing
Sows denied nesting materials show redirected behaviors including bar-biting during the pre-farrowing period
Nest building behavior correlates with better mothering behavior and reduced piglet crushing rates
EU legislation requires that sows have access to adequate nesting materials before farrowing

Welfare Considerations

The frustration of nest building motivation is one of the most well-documented welfare failures in intensive pig production. Research demonstrates clearly that sows approaching farrowing have an overwhelming drive to build a nest and that denying materials causes acute behavioral distress. The sow alternates between frustrated attempts to root and manipulate her environment, activity consistent with what we observe in animals prevented from completing strongly motivated behaviors. Providing even small quantities of straw dramatically reduces this frustration and improves farrowing welfare for both sow and piglets.

What You Can Do

Provide nesting materials including straw, hay, or paper to all sows in the 24 hours before farrowing
Advocate for production standards requiring nesting material provision during the farrowing period
Support food producers certified under schemes requiring nesting materials for sows
Learn about the welfare science of pig nest building to advocate effectively for this basic welfare improvement
Monitor farms for compliance with nesting material requirements where applicable regulations exist
Support industry transition to systems that allow nest building as a standard practice
Recognize that providing materials is a minimal welfare improvement that addresses a profound behavioral frustration