Reviewing the scientific evidence for sentience and emotional complexity in farm animals and its implications for welfare standards.
Farm animal sentience research has fundamentally changed the scientific understanding of what farm animals experience and therefore what welfare standards are morally required. The evidence for emotional complexity, social intelligence and pain experience in pigs, cattle, sheep, chickens and fish is now sufficiently robust to underpin strong moral obligations to prevent unnecessary suffering in farming systems. Yet welfare standards in many jurisdictions still reflect older assumptions of limited sentience, allowing practices that the current evidence base does not support. The welfare implications of sentience research are not merely academic - they provide the scientific foundation for legislative and industry reform that the evidence demands.