Comparing Visual-Only and Visual-Palpation Post-Mortem Lung Scoring Systems in Slaughtering Pigs

Simple Summary Lung lesions, which are common findings in finisher pigs, are considered useful indicators of animal health and welfare at the slaughterhouse. Several methods for evaluating such lesions have been developed, and selecting the best system is critical for obtaining reliable and consistent data. In this view, the aim of this study was to compare two well-known scoring methods (Madec and Blaha methods) using data on lung lesions collected by two operators in an Italian high-throughput abattoir under routine slaughter conditions. Overall, there was a satisfactory level of agreement between the two methods, although a discrepancy in accurately recognizing healthy lungs and minor injuries between the two systems has been observed. According to our results, the Blaha method is a visual-only system applicable to very large abattoirs. It can be easily used to provide an overview of the respiratory health status of pigs, although it can yield a higher percentage of false negative results. On the other hand, the Madec method can provide more detailed results but would be more challenging to use for continuous monitoring in large abattoirs because it requires both visual and palpation assessments. Respiratory diseases continue to pose significant challenges in pig production, and the assessment of lung lesions at the abattoir can provide valuable data for epidemiological investigations and disease surveillance. The evaluation of lung lesions at slaughter is a relatively simple, fast, and straightforward process but variations arising from different abattoirs, observers, and scoring methods can introduce uncertainty; moreover, the presence of multiple scoring systems complicates the comparisons of different studies, and currently, there are limited studies that compare these systems among each other. The objective of this study was to compare validated, simplified, and standardized schemes for assessing surface-related lung lesions in slaughtered pigs and analyze their reliability under field conditions. This study was conducted in a high-throughput abattoir in Italy, where two different scoring methods (Madec and Blaha) were benchmarked using 637 plucks. Statistical analysis revealed a good agreement between the two methods when severe or medium lesions were observed; however, their ability to accurately identify healthy lungs and minor injuries diverged significantly. These findings demonstrate that the Blaha method is more suitable for routine surveillance of swine respiratory diseases, whereas the Madec method can give more detailed and reliable results for the respiratory and welfare status of the animals at the farm level.

Automated summary

Lung lesions in finisher pigs are useful indicators of animal health and welfare. This study compared two scoring methods (Madec and Blaha) for evaluating lung lesions in an Italian abattoir. The results showed a good agreement between the methods for severe or medium lesions but differed in identifying healthy lungs and minor injuries. The Blaha method is suitable for routine surveillance, while the Madec method provides more detailed and reliable results.