## 4 Discussion  
This prospective study documented the prevalence of severe lesions in the rear, middle, and shoulder regions of carcasses obtained from heavy pigs slaughtered at a commercial abattoir and evaluated the associations between carcass severe lesions and pre-slaughter conditions. Longer waiting before unloading and improper handling practices at the abattoir were two of the major factors that were found to affect carcass lesion severity the most. Lairage pen space allowance was also found to affect rear and shoulder severe lesions, and the batches that were transported in the trailer had an increased prevalence of shoulder severe lesions compared with those transported in the lorry. Our results supported the hypothesis that besides mixing unfamiliar pigs, other pre-slaughter factors can have a  
Figure 4: Association between pre-slaughter conditions and severe lesions in the front region (shoulder) of heavy pig carcasses: (**a**) forest plot and (**b**) regression tree plot. In forest plot (**a**), * stands for \(p\) < 0.05, and *** for \(p\) < 0.001.  
major effect on carcass damage. The approach employed in the present study considered the rear, middle and front parts of the carcass separately, in agreement with the approach used in other studies [7]. This approach was selected as lesions in different anatomical locations can cause economic losses of different entities. In heavy pigs, severe lesions in the rear part of the carcass may be more detrimental, as defects and lesions which make trimming necessary cause the exclusion of the damaged thighs from the PDO circuit [44]. Therefore, the high economic losses caused by damaged pig carcasses [1; 2; 3] may further increase when bruises are located on thighs intended for PDO ham production, as the value of PDO hams is 20 to 40% higher than that of non-PDO [12]. The average prevalence of severe lesions in the three anatomical regions was overall higher than the prevalence reported in the scientific literature. The prevalence of rear severe lesions identified in the present study (i.e., 6.92%) was higher than what was observed in [PERSON] et al. [7] (2.56%) in pigs slaughter at about 106 kg live weight. In the present study, the percentage of unacceptable severe lesions in the rear region of heavy pig carcasses may also have been greater (i.e., 33.14%), considering that the PDO ham circuit requires thighs with intact skin, and hams coming from the rear scored as 2 are often discarded. Due to practical constraints, however, the fate of the thighs obtained from the carcasses considered in the present study remains unknown. Comparing the prevalence of severe lesions in the middle (i.e., 11.87%) and shoulder regions (i.e., 6.83%) found in our study with those reported in the literature [7; 45], it is clear that severe lesions were much more frequent in our sample. This result seems to confirm that heavy pigs have features that increase the risk of damaged carcasses [12; 13], and must be therefore handled taking into consideration the increased risks posed by the heavier bodyweight. This point is also of vital importance, considering the fact that a survey on consumer perceptions showed that the final consumer expects from PDO products not only better organoleptic quality but also greater attention to aspects concerning animal welfare [46]. Several associations between the pre-slaughter conditions and events annotated at the abattoir and the prevalence of severe lesions were identified. A higher prevalence of severe lesions in the rear region of heavy pig carcasses was noticed for the batches subjected to longer waiting time before unloading, more space allowance in lairage pens, and more frequent hitting with a stick when moved towards the stunning area. Other factors associated with increased severity in rear lesions were the higher percentage of panting animals at unloading (T1) and the higher prevalence of ear discoloration in pigs at T2.