Assessment of the impact of omitting palpation of the lungs and the liver at meat inspection

Meat inspection of finisher pigs is gradually moving from traditional inspection involving palpation and incision to a more visual inspection. However, what do we miss if we no longer palpate and incise? This is addressed in this paper which focuses specifically on palpation of the lungs and the liver. A risk assessment following international guidelines was undertaken. The assessment shows that omission of these routine palpations on finisher pigs from controlled housing (i.e. herds with high biosecurity) will have no significant impact on food safety. The reasoning for reaching these conclusions is presented in the following. Introduction The main aim of meat inspection is to ensure safe and savoury meat. However, much has changed since the birth of modern meat inspection 100 years ago. Today, Campylobacter, Salmonella and Yersinia fill up the human statistics for zoonotic infections. And it is well-known that meat inspection in itself can do only little to mitigate the risk associated with such agents, because they do no result in macroscopic lesions in affected carcasses or plucks. In fact, palpation and incision result in cross-contamination of the carcasses. In line, it has been suggested to omit unnecessary palpation and incisions to limit the cross-contamination with Salmonella. However, what would we risk if we stopped the routine palpations and incisions? Two earlier risk assessments following international guidelines concluded that omitting routine palpation of the mandibular and mesenterial lymph nodes and discontinue the routine opening of the hearts did not carry any increase in the food safety risks (Alban et al., 2008; Alban et al., 2010). Next, we have looked at the impact of omitting palpation of the lungs, the liver and their lymph nodes. We looked at food safety as well as the impact on animal health (including the ability to identify notifiable diseases) and welfare of the pigs. Only the food safety results are described in this paper. For the other aspects, the reader is kindly referred to the full risk assessment which can be found on the following link: http://www.lf.dk/~/media/lf/Aktuelt/Publikationer/Svinekod/ Risk%20assessment_lungs%20liver%202013%2002%2028.ashx Material and Methods The work followed OIE guidelines for risk assessment. This implies that the following five steps were undertaken: Hazard identification, release assessment, exposure assessment, and consequence assessment. Finally, risk estimation was made based on an integration of the four previous steps. Data consisted of a comparison study involving 3,000 plucks, own collection of slaughterhouse samples (N=104) sent for microbiological investigation, slaughterhouse statistics, literature and expert opinion. Results Hazard identification: embolic pneumonia and liver abscesses were identified as the two most important lesions that might escape detection if routine palpation is omitted. This was based on a literature review and discussions with experts in the field. Release assessment: Two studies were conducted to assess the proportion of plucks with embolic pneumonia that might escape detection, if visual inspection is applied instead of traditional inspection. The first was a comparison study including 3,000 plucks (Table 1). The second consisted of an evaluation of 104 plucks with embolic pneumonia collected during meat inspection (Table 2). The comparison study showed that one out of three cases found in traditional inspection was missed by visual inspection (Table 1). Likewise, the evaluation study showed that around one out of five cases would be missed if visual inspection was used compared to traditional inspection.