Positive welfare assessment in pigs has moved beyond the Five Freedoms to identify specific indicators of good welfare, enabling more nuanced assessment of pig mental states.
The shift toward positive welfare assessment in pigs represents a conceptual advance beyond simply measuring the absence of suffering. Welfare science has developed and validated a toolkit of positive indicators that reveal whether pigs are experiencing something like enjoyment, curiosity, and contentment - not just the absence of pain and fear. Play behaviour is a particularly robust indicator: pigs in good welfare states engage in spontaneous running, jumping, and social play, while these behaviours are suppressed by stress, fear, or physical discomfort. Tail posture is assessable even in large commercial groups - raised tails indicate positive affect, while tucked tails signal negative states. Cognitive bias testing, in which pigs trained on an ambiguous cue respond in 'optimistic' or 'pessimistic' ways depending on their welfare history, provides a window into emotional states. These positive indicators are now incorporated into commercial welfare assessment programmes and allow farm inspectors to distinguish farms where pigs are merely surviving from those where they are genuinely thriving. The goal of achieving positive welfare states, not just preventing suffering, represents an ambitious but achievable aspiration for commercial pig production.