Modern animal welfare science has moved beyond simply measuring the absence of suffering to identifying positive welfare states including play, curiosity, and joy that animals can experience.
The shift toward positive welfare in animal science represents a significant conceptual advance. Rather than defining good welfare as the absence of pain and distress, the positive welfare framework asks what conditions allow animals to experience positive emotional states including curiosity, play, social bonding, and competence. Play is a particularly valuable positive welfare indicator as animals only play when their fundamental needs are met and they feel safe. Seeking behaviors indicating curiosity and exploration are positive welfare markers. Specific facial expressions associated with positive states have been identified in horses, sheep, and pigs. Environments that allow animals to exercise agency and control over their environment produce more positive welfare states than those where they are passive recipients of care. This framework is transforming how we design housing and management for both farm and companion animals.