Welfare science on environmental complexity for farmed pigs, examining the evidence that enriched environments improve pig welfare, reduce harmful behaviors, and support positive affective states.
Environmental complexity for pigs is not a luxury but a welfare necessity recognized by decades of research demonstrating that barren environments cause measurable chronic suffering. Pigs are among the most intelligent domestic animals — their cognitive capacities are estimated to exceed those of dogs — and they have commensurate needs for environmental engagement, problem-solving opportunities, and varied sensory experience. The conventional intensive pig system, with barren concrete floors and minimal enrichment, provides essentially none of what pig cognition requires. The transformation of pig welfare requires comprehensive environmental enrichment: rooting materials that allow natural foraging behavior, wallowing access for thermoregulation and positive affect, social groups that permit stable social relationships, and space adequate for normal movement and play.