P38 | Validation of a protocol for classifying traumatic wing lesions as part of the assessment of overall poultry welfare conditions at the slaughterhouse

Purpose. This study was conducted with the aim of validating a protocol for classifying load-bearing injuries in broiler chickens, in order to provide the official veterinarian with an additional tool for the systematic assessment of animal welfare at the slaughterhouse. Materials and Methods. The study was conducted in Piedmont, at an industrial slaughterhouse, on a sample of over 13,000 animals, divided into 18 batches. Three categories of broilers were observed, classified by sex and weight: roasting chickens, weighing less than 1.7 kg (R); females weighing over 2.4 kg (F) and males weighing more than 3.2 kg (M). For each batch considered, a sample equal to 10% of the subjects was selected. The data was collected over a period of four months (November 2024 - March 2025) by three evaluators who are graduates in Veterinary Medicine with specific expertise in the inspection of food of animal origin (or food safety). For each batch, a double assessment was performed, pre- and post-mortem. Traumatic wing injuries were classified into three severity categories by visual inspection, designated as 0 (implantation injury), 1 (mild injury), and 2 (severe injury). A final validation index was then calculated to measure the consistency between the two inspection phases, improving the overall reliability of the data. The normality of the data was investigated using the Lilliefors Kolmogorov-Smirnov test. The non-parametric Kruskal-Wallis test was used to analyze the difference between the various types of lesions and weight category. Results. Out of the total number of carcasses inspected (13,430), 308 type 0 lesions (2.3%), 580 type 1 lesions (4.3%), and 416 type 2 lesions (3.1%) were detected. The validation indicator showed a progressive increase, suggesting improvement with experience. A probable correlation between body weight and injury frequency was highlighted, suggesting the need to define differentiated cut-offs for each weight category. The correlations between weight and injuries, although not statistically significant, indicate trends consistent with a possible influence of weight on injury frequency. Conclusions. Based on the collected data, it can be stated that the incidence of traumatic wing injuries in broiler chickens can serve as a useful indicator for official control, aimed at evaluating the adequacy of animal welfare measures during the loading, transport, and processing of carcasses in the establishment. Finally, the training activity conducted demonstrated the importance of standardizing the evaluation approach among operators, contributing to a reduction in inter-observer variability and the reliability of the proposed classification system. The detection of such injuries is integrated into the broader assessment and monitoring activity of other already established indicators such as DOA (mortality on arrival), SIS (hygienic-sanitary waste), and FPL (foot lesions). Among the main critical issues that emerged during the study, the difficulty in distinguishing between type 2 lesions, attributable to injuries occurring intra vitam, and type 0 lesions, attributable to the slaughtering process, is noted. To reduce the risk of underestimating the true incidence of type 2 injuries, operators have been advised to adopt a precautionary approach, classifying all doubtful traumas as type 2 injuries.