Farm Animals

Pig Farrowing Nest Building

The nest-building drive in sows approaching farrowing is one of the strongest behavioral motivations in farm animals, largely frustrated in confinement.

Key Facts

Nest building begins 24-6 hours before birth in free-ranging sows
The motivation to build a nest is so strong that sows deprived of material show prolonged frustration
Nest building improves piglet survival and sow-piglet bonding
Even token substrate reduces frustration behaviors in nest-building sows
The strength of nest-building motivation demonstrates the level of suffering when it is frustrated

Welfare Considerations

Frustration of nest-building motivation in farrowing sows represents one of the clearest welfare violations in modern pig farming. The motivation is intense and species-typical. Frustrating it causes measurable suffering. Providing even modest nesting material dramatically reduces frustration behavior. Alternative farrowing systems that allow nesting have been commercially demonstrated.

What You Can Do

Support campaigns for nesting material requirements in farrowing regulations
Advocate for loose farrowing systems that allow natural nesting behavior
Choose pork from farms that provide farrowing sows with nesting material
Support research on nesting material provision in commercial farrowing
Raise awareness of farrowing sow frustration as a significant welfare issue