Farm animals including cattle, sheep, and pigs express emotional states through facial expressions that can be reliably decoded using validated scales developed by welfare scientists.
Facial expression coding in farm animals represents a democratisation of welfare assessment: tools that were once confined to neuroscience laboratories are now simple enough for farm use with brief training. The insight that animals communicate emotional states through facial expressions was anticipated by Darwin but required decades of careful ethological and neuroscientific research to validate rigorously. Farmers who learn to read the emotional expressions of their animals — recognising the orbital tightening of a sheep in pain, the asymmetric ear positions of a stressed cow — gain direct access to welfare information that their animals are continually broadcasting. The challenge is making this knowledge routine in commercial practice.