Play behaviour in pigs is a reliable indicator of positive welfare states. Understanding when and why pigs play — and what prevents play — provides insight into the quality of their lived experience.
Play behaviour is not frivolous — it is a welfare indicator of fundamental importance. Animals that are stressed, in pain, chronically hungry, or fearful do not play. When pigs play, they are communicating through behaviour that their immediate welfare needs are met and they have the psychological and physical resources to engage in behaviour that serves no immediate survival function. Increasing play frequency in commercial pig production requires the same inputs that improve welfare across all dimensions: adequate space, environmental complexity, enrichment that can be manipulated, appropriate group composition, and absence of chronic stressors. Measuring play frequency as part of welfare outcome assessment provides a positive indicator alongside the negative outcome measures typically recorded.