Nesting Behavior in Sows Before Farrowing

The motivation to build a nest before farrowing is among the strongest behavioral drives in sows; providing nesting materials satisfies this need and reduces pre-farrowing stress substantially.

Key Facts

Sows in natural environments spend 6-12 hours building a nest before farrowing
Nest-building motivation persists even when physical materials are unavailable, causing frustrated behavior
Providing straw or other nesting material to sows in the hours before farrowing reduces stress hormones
Reduced pre-farrowing stress correlates with more attentive maternal behavior and lower piglet crushing rates
Some free-farrowing systems specifically design for nest-building opportunity as a welfare priority

Welfare Considerations

Nest-building before farrowing is one of the most compelling examples of a behavioral imperative in farm animals. The motivation is so strong that sows denied nesting materials perform nest-building movements in thin air - sham nest building that satisfies the behavioral drive incompletely without any substrate. Providing even modest amounts of nesting material including straw, paper, or hessian in the hours before expected farrowing dramatically reduces pre-farrowing stress indicators and improves maternal behavior outcomes. The welfare benefit is achieved at minimal cost and represents one of the highest-return welfare investments in pig production.

What You Can Do

Support welfare standards that require nesting material provision to sows before farrowing
Choose pork from farms certified to standards including farrowing welfare provisions
Advocate for universal nesting material requirements in farrowing welfare regulations
Support research on optimal nesting material types for different farrowing system designs
Encourage farmer adoption of nesting provision through demonstration of both welfare and performance benefits