Docking the value of pigmeat? Prevalence and financial implications of welfare lesions in Irish slaughter pigs

Abstract

Expansion of the meat inspection process to incorporate animal-based welfare measurements could contribute towards significant improvements in pig (Sus scrofa domesticus) welfare and farm profitability. This study aimed to determine the prevalence of different welfare-related lesions on the carcase and their relationship with carcase condemnations (CC) and carcase weight (CW). The financial implications of losses associated with CC and CW reductions related to the welfare lesions were also estimated. Data on tail lesions, loin bruising and bursitis, CW and condemnation/trimming outcome (and associated weights) were collected for 3,537 slaughter pigs (mean [± SEM] carcase weight: 79.2 [± 8.82] kg). Overall, 72.5% of pigs had detectable tail lesions, whilst 16.0 and 44.0% were affected by severe loin bruising and hind limb bursitis, respectively. There were 2.5% of study carcases condemned and a further 3.3% were trimmed. The primary cause of CC was abscessation. While tail lesion severity did not increase the risk of abscessation, it was significantly associated with CC. Male pigs had a higher risk of tail lesions and of CC. The financial loss to producers associated with CC and trimmings was estimated at €1.10 per study pig. CW was reduced by up to 12 kg in cases of severe tail lesions. However, even mild lesions were associated with a significant reduction in CW of 1.2 kg. The value of the loss in potential CW associated with tail lesions was €0.59 per study pig. Combined with losses attributable to CC and trimmings this represented a loss of 43% of the profit margin per pig, at the time of the study, attributable to tail biting. These findings illustrate the magnitude of the impact of tail biting on pig welfare and on profitability of the pig industry. They also emphasise the potential contribution that the inclusion of welfare parameters at meat inspection could make to pig producers in informing herd health and welfare management plans.

Effects of scalding and dehairing of pig carcasses at abattoirs on the visibility of welfare-related lesions

“…Tail lesion prevalence in the current study was approximately half the prevalence reported in previous studies examining tail lesions in pig herds on the island of Ireland (Harley et al, 2012a;Harley et al, 2014). It is possible that this reflects a decrease in the prevalence of tail lesions in pig herds on the island of Ireland.…”

“…Some researchers argue that these processes could make welfare-related carcass damage difficult to detect (Taylor et al, 2010;Aaslyng et al, 2013). However, others suggest that this damage may be more detectable after these processes (Harley et al, 2014;Stärk et al, 2014). It appears that the current study is the first to actually investigate this in a controlled way.…”

“…This may be a difficult task, particularly with regard to loin bruising, the aetiology of which remains uncertain. It has been theorised that mounting behaviour contributes to loin bruising (Harley et al, 2014). However, there has been no conclusive evidence to date that this is the case.…”

“…A simplified version of Harley et al's (2014) loin bruise scoring system was used whereby 'mild' and 'severe' bruise categories were combined. Therefore, loin bruises were recorded as being either present (when observed in either mild or severe form) or absent (Figure 1).…”

“…Furthermore, only a handful of isolated studies have examined tail lesion prevalence by carrying out abattoir-based assessments (Hunter et al, 1999;Valros et al, 2004;Harley et al, 2012a). Similarly, information on loin bruising prevalence is limited, perhaps due to the fact that it has only recently been identified as a welfare issue (Harley et al, 2014). Skin lesions, on the other hand, have been studied for decades.…”