Higher placement stocking density is associated with increased antibiotic use and footpad lesions in conventional...

High stocking densities in broiler production have been linked to reduced air and litter quality, which can negatively affect broiler welfare. This study assessed the association between placement stocking density and three key health and welfare indicators in conventional broilers: antibiotic treatments, mortality, and footpad lesion (FPL) scores. Data from 29,542 Dutch broiler flocks (2017-2021) were analyzed using generalized linear mixed models. Placement stocking density was not associated with antibiotic treatment during the first week of production but was positively associated with the probability of treatment after the first week (odds ratio 1.08; 95% CI [1.05, 1.11]; p < 0.001). No association was observed with mortality until thinning. Higher placement stocking density was also associated with higher FPL scores (score ratio 1.09; 95% CI [1.08, 1.10]; p < 0.001). Excluding farms with poor historic FPL scores provided similar results. Together, these findings suggest that higher placement stocking density may increase the occurrence or transmission of infectious diseases, leading to increased antibiotic use, while also adversely affecting footpad health. Reducing stocking density may therefore improve broiler health and welfare in conventional production systems.