Farrowing crates prevent piglet crushing but severely restrict sow movement, creating a welfare tradeoff that alternative systems are resolving.
Sows in farrowing crates show indicators of frustration and chronic stress including stereotypies and aggression at crate removal. The behavioral need to nest before farrowing is so strong that crated sows perform nest-building movements against bare concrete floors for hours. System alternatives exist and improve sow welfare with manageable piglet loss.