Improvement of Feather Condition and Welfare Indicators Following the Provision of Pecking Materials to Laying Hens: A Meta-Analysis

This meta-analysis aimed to evaluate the effects of providing pecking materials as environmental enrichment on feather damage and selected physical welfare indicators in laying hens. A systematic literature search was conducted using electronic databases, and studies investigating the effects of pecking material provision on region-specific feather damage or physical welfare parameters were selected according to predefined inclusion criteria. A total of eight articles comprising ten independent experiments were included in the final analysis. The pooled results indicated that the provision of pecking materials significantly improved feather condition in the neck, back, and wing regions, as well as overall body feather status. In addition, a significant reduction in comb wound counts was observed, suggesting a decrease in injurious pecking behavior. These findings imply that providing manipulable pecking materials may redirect pecking activity away from conspecifics and stimulate natural exploratory and foraging behaviors, thereby contributing to improved welfare outcomes. Despite these positive effects, heterogeneity was observed among studies, which may be attributed to differences in housing systems, hen genotype and age, types of pecking materials, and feather scoring methods. Therefore, the results should be interpreted with caution. Nevertheless, the present findings support the practical application of pecking materials as an environmental enrichment strategy to enhance behavioral and physical welfare in laying hens. Further standardized, large-scale, and long-term studies are required to strengthen the evidence base and improve the generalizability of the conclusions.