Sows have strong instincts to build nests before farrowing and to bond with their piglets, but intensive confinement systems prevent these natural behaviors entirely.
The farrowing crate is one of the most debated welfare issues in pig farming. While designed to reduce piglet crushing deaths, it also completely prevents the sow from performing her nest-building drive — a highly motivated behavior that, when thwarted, causes significant frustration and distress. Sows in crates cannot turn around, groom their piglets normally, or respond to piglet distress calls with movement. Loose farrowing systems with good management can achieve comparable piglet survival while allowing far greater expression of natural maternal behavior.