Research into pig positive emotional states has transformed welfare science, enabling assessment of not just the absence of suffering but the presence of positive experiences.
The shift from negative welfare assessment (absence of suffering) to positive welfare assessment (presence of good experiences) has been transformative for pig welfare science. Pigs display a rich repertoire of positive emotional indicators — play, anticipatory behavior, optimistic cognitive bias — that can be measured systematically to assess whether management systems provide genuinely good lives rather than merely tolerable ones. Play is a particularly sensitive indicator: pigs play only when sufficiently comfortable with their environment to engage in non-essential behavior. High-play environments consistently produce pigs with better health, growth, and behavioral outcomes. The science makes clear that achieving merely acceptable welfare is insufficient — providing positive experiences should be the explicit welfare goal, and producers can now be evaluated against that standard using validated behavioral indicators.