Effects of plastic huts and metal ramps as environmental enrichment on welfare and production performance in Ross 308 broilers up to 32 d

Environmental enrichment has the potential to improve broiler welfare by promoting optimal psychological and physiological well-being. However, the effect of enrichment depends on factors like enrichment type, quantity, combination, and the extent to which it is used by the birds. This study investigated the effects of plastic huts and metal ramps on welfare and production outcomes in over 7,000 Ross 308 broilers raised to 32 days of age and housed in either enriched or non-enriched environments simulating commercial conditions. While overall production performance and mortality were similar between treatments, several welfare-related differences were observed. Enrichment use varied with age and enrichment type, with birds using the tops of metal ramps more than plastic huts and using the area underneath plastic huts more than ramps on most days, except on day 31. Broilers provided with enrichments exhibited lower heterophil-to-lymphocyte ratios, suggesting reduced stress or altered immune response. Access to enrichment also resulted in a small but meaningful increase in wing and leg stretching behavior during the photoperiod. No effects were found on gait, footpad and hock dermatitis, plumage cleanliness, or fearfulness. Overall, broilers made substantial use of the enrichments, particularly underneath the plastic huts, which promoted stretching behavior and may have reduced stress without compromising health-based welfare indicators or productivity.