Production chain parameters associated with condemnation at slaughter due to skin lesions and cellulitis in broiler chickens: A retrospective observational study

Cellulitis in commercially reared broiler chickens is a common cause of condemnation at slaughter. In this retrospective observational study, we aimed to identify parameters in the broiler production chain that could be associated with the condemnation percentage due to dermatitis/cellulitis at meat inspection. Production data were acquired from an industry production database and involved 90 farms and 4697 broiler chicken flocks placed from May 2021 to November 2022. Data were analysed using mixed effect modelling with broiler compartment nested in farm as the random effect. The analyses showed that higher mean age of parent flocks and higher stocking density at placement in combination with age of chicken flocks at slaughter were associated with higher condemnation due to dermatitis/cellulitis. Higher footpad score was associated with lower condemnation due to dermatitis/cellulitis, even at the slaughterhouse which had a higher dermatitis/cellulitis condemnation percentage. In flocks where thinning was practiced, defined as by more than four days between slaughter occasions, there was lower condemnation due to dermatitis/cellulitis. In addition, small broiler compartments, season, feed mills and feed company were associated with the outcome. There was a risk of information bias as multiple stakeholders contributed data. As several parameters were associated with condemnation due to dermatitis/cellulitis the results suggest a multi-factorial preventive approach. Further, the study emphasizes the need for further research to understand how these parameters affect the condemnation due to dermatitis/cellulitis.