The science of farm animal enrichment has advanced significantly. Understanding what actually works guides both welfare certification standards and on-farm practice improvement.
Enrichment science has moved beyond the observation that 'enrichment helps' to specifying which enrichments help which species in which contexts. For pigs, the science is clear: manipulable organic material that can be rooted and chewed outperforms non-manipulable objects by large margins. A hanging chain loses enrichment value within days; straw that can be rooted provides sustained behavioral engagement. For laying hens, perch access, dust bathing substrate, and nest boxes address specific behavioral drives that, when unmet, cause the frustration that leads to feather pecking. The practical implications for certification standards are direct: specifying minimum enrichment quality criteria rather than just enrichment provision produces meaningful welfare improvements. The gap between what enrichment science recommends and what minimum legal requirements mandate is where the welfare improvement opportunity lies.