SHORT COMMUNICATION: Investigating woody breast disease and broiler chicken activity using an automated tracking software program

Objective: This research quantified the effect of woody breast disease (WBD) presence and severity on activity in broilers. Materials and Methods: Broiler cockerel chicks (n = 27) were enrolled over 2 periods and individually housed. Video data were collected continuously from 21 to 55 d of age. Behavior was analyzed over a 4-h interval using EthoVision XT automated tracking software to quantify total activity. Birds were slaughtered at 55 d of age and assigned a woody breast severity score (0-2) based on manual palpation and visual observation. Results and Discussion: Of the 25 birds that survived for the duration of the study, 6 birds were assigned a severity score of 0 (no evidence of WBD), 14 a severity score of 1 (firm focal lesions), and 5 a severity score of 2 (diffuse firmness of the entire pectoralis major muscle). Neither WBD presence nor severity had an effect on total activity (P > 0.05). In the present study, no effect of WBD on activity was detected using an automated tracking software program for behavior quantification. However, limitations of the software and the potential presence of microscopic lesions in birds with a severity score of 0 may be contributing to this outcome. Implications and Applications: Although WBD has significant financial implications for the poultry industry, limited research has evaluated the effect of WBD on bird welfare and behavior. Future studies should measure a more diverse set of behaviors while also analyzing muscle histology to better elucidate any associations between WBD and behavior.