Decades of research on pig enrichment has produced clear evidence about what types of enrichment provide genuine welfare benefits and what merely provides the appearance of enrichment without addressing behavioral needs.
The pig enrichment evidence base is now sufficiently robust to make clear distinctions between effective and ineffective enrichment. Hanging chains and plastic toys — the most commonly provided "enrichment" in commercial pig production — have weak evidence of welfare benefit because they do not engage the rooting and foraging motivations that drive most pig behavioral need. Straw and fibrous manipulable substrates, by contrast, engage these motivations directly: pigs root through straw, eat small quantities, build nests in it, and investigate its changing properties as it becomes compressed and soiled — all behaviors that maintain engagement and reduce boredom. The barrier to straw use in commercial systems is primarily technical — slurry management systems are designed around liquid manure and cannot handle fibrous bedding — but this is an engineering challenge with known solutions, not an insurmountable constraint.