A comprehensive review of pig positive emotions research concludes that pigs are capable of genuine positive welfare states that welfare standards should actively promote rather than merely allowing by default.
Research into pig positive emotions has matured to the point where validated indicators exist and their welfare significance is well-established. The final conclusion is that welfare standards should not merely prohibit harm but actively require conditions that enable positive welfare states. Pigs experiencing good welfare have better health, better behaviour, and better productive performance - positive emotions are not a luxury but a component of genuinely good welfare.