Rooting is the most fundamental behavioural need of pigs — a drive so powerful that its frustration causes chronic stress and contributes to the tail biting and aggression that plague intensive pig systems.
The frustration of rooting behaviour in barren pig systems creates chronic psychological stress that manifests as redirected behaviour — biting tails, flanks, and ears of pen-mates. This is not misbehaviour but a normal drive expressed inappropriately because the appropriate outlet has been removed. Providing straw — an inexpensive and widely available material — dramatically reduces these welfare harms. The barrier to adoption is largely perceived incompatibility with slatted floor systems used for manure management. However, evidence from farms using straw in bedded pens and partial bedding systems shows that good welfare and efficient management are compatible. The will to change, supported by policy requirements and welfare premiums, is what is most lacking.