Scientific evidence for the sentience of farmed species has accumulated dramatically in recent decades, transforming our understanding of what farmed animals experience and why welfare matters.
The science of farmed animal sentience has moved from contested to well-established. Studies across species demonstrate not just nociception but subjective suffering — the 'what it is like' dimension of pain. Chickens show empathy for distressed chicks; pigs demonstrate pessimistic cognitive bias in poor welfare conditions; fish seek analgesics when injured. This evidence base does not merely inform welfare standards but fundamentally challenges the ethical framework that permits current intensive production. The gap between what science shows animals experience and what food systems permit them to experience is one of the defining ethical challenges of our time.