The maternal behavior of sows is severely restricted by farrowing crates, causing distress and preventing natural behaviors that are important for sow and piglet welfare.
The farrowing crate was developed to prevent sow-caused piglet deaths from crushing, but it does so by completely restricting sow movement during one of the most behaviorally significant periods of her life. Sows show intense nesting behaviors before birth as a fundamental drive, and preventing this expression causes significant frustration and distress. Research documents that sows in crates show higher stress behaviors than those in loose housing systems. Alternative systems including free-farrowing pens and loose housing with protective structures can achieve comparable piglet survival with better sow welfare when well-designed and managed.