Decades of welfare science research on pigs has established the evidence base for current welfare standards and revealed the complex behavioral, cognitive, and emotional needs that commercial production systems must address.
Pig welfare science has transformed understanding of what pigs need for good welfare, demonstrating cognitive abilities and emotional depth that necessitate complex environments, social stability, and appropriate enrichment. Key research findings including the demonstration of pessimistic cognitive bias in pigs given poor environments, play behavior indicating positive welfare states, and pain recognition through grimace scales have directly influenced welfare standards and assessment methods. The science is clear that barren, overcrowded environments cause genuine psychological as well as physical welfare suffering in pigs.