The conventional farrowing crate confines sows for 3-5 weeks around parturition, severely restricting movement and the ability to express natural behaviours including nest-building, rooting, and postural changes. Sows in crates show elevated stress indicators, inability to respond to piglet distress, and sustained frustration. The crate is widely regarded as one of the most welfare-compromising housing systems in commercial pig production.
In natural settings, sows typically leave the group 1-2 days before farrowing to find an isolated site. They engage in intensive nest-building behaviour lasting several hours, collecting and arranging vegetation. Nest quality is associated with reduced birth duration, lower piglet mortality, and improved sow welfare. After farrowing, sows are attentive to piglets and respond to distress vocalisations.
Several alternatives have been developed and are in commercial use:
The primary reason given for farrowing crate use is piglet loss to overlying (crushing by the sow). Evidence indicates that well-designed crate-free systems can achieve comparable or only modestly higher piglet losses, particularly with good stockmanship and appropriate pen design. Genetics (dam lines selected for mothering ability) significantly affect outcomes in crate-free systems.
Even within crate systems, providing suitable nesting material (straw, wood shavings) shortly before farrowing reduces stereotypic rooting behaviour, lowers cortisol, and improves piglet outcomes. This demonstrates the strength of the behavioural drive and the welfare cost of frustrating it.
Major pig breeding companies (Topigs Norsvin, PIC, JSR) are developing sow lines better suited to crate-free systems, including improved maternal behaviour, reduced reactivity, and better body structure. These genetic improvements are expected to accelerate the transition to welfare-compliant systems across Europe and beyond.