Scientific research has revealed that cattle, pigs, sheep, and chickens have emotional lives and cognitive abilities that demand welfare consideration far beyond preventing physical harm.
Farm animal sentience research has fundamentally altered the moral case for their welfare. These are animals with memories, social bonds, emotional states, and cognitive abilities sufficient to experience complex forms of suffering beyond simple physical pain. A dairy cow separated from her calf experiences something functionally equivalent to grief. A pig in a barren pen experiences something functionally equivalent to frustration and boredom. Welfare standards that only address physical health are insufficient given this evidence.