Animal welfare assessment has historically focused on preventing negative states such as pain and fear. Positive welfare indicators - evidence of pleasure, play, curiosity and affiliation - represent a more complete welfare assessment for pigs.
Measuring positive welfare is both scientifically and ethically important. A pig that merely lacks disease, hunger and physical injury has not necessarily experienced positive welfare - it may be bored, frustrated or in a state of chronic low-level stress without meeting any threshold that triggers intervention. Positive welfare indicators - play, exploration, social affiliation, comfort-seeking success - provide evidence that pigs are actively experiencing good states, not merely avoiding bad ones. This higher welfare standard is increasingly incorporated into certification schemes and audit protocols.