Developing reliable, practical measures of animal welfare is essential for assessing welfare status, driving improvement, and making evidence-based policy decisions.
Welfare measurement science determines what gets measured and therefore what gets managed. Early welfare frameworks focused on negative indicators - freedom from pain, disease, fear. Modern frameworks explicitly measure positive welfare states including opportunities for play, exploration, social bonding, and positive affect. This shift matters: a farm animal that is fed, healthy, and not in pain but has no opportunity for motivated natural behaviors has poor welfare by modern standards but acceptable welfare by older frameworks. Developing practical, low-cost welfare measures that capture positive states as well as negative ones is essential for driving genuine welfare improvement beyond basic suffering prevention.