Pre-mortem sound level measurement: Noninvasive tool for welfare and meat quality assessment in pigs

The aim of this study was to investigate the effect of noise levels in the stunning box on oxidative stress biomarkers and meat quality traits in slaughter pigs. The experiment included 60 pigs, approximately six months old, with an average live weight of around 110 kg. For each animal, a comprehensive set of oxidative stress parameters was measured (glucose, AOPP, ceruloplasmin, GSH, TAC, TOS and the oxidative stress index), along with meat quality indicators (pH and temperature, sensory and instrumental colour, water-holding capacity and pork quality classes). Exposure of slaughter pigs to noise levels above 105 dB resulted in increased plasma TOS concentrations and the oxidative stress index. Furthermore, elevated noise levels adversely affected meat pH and temperature in the musculus longissimus lumborum 45 minutes post-mortem, cooking loss, L*, a* and b* values, sensory colour score and the incidence of red, firm, non-exudative and pale, firm and non-exudative pork. In conclusion, the findings of this study indicate that monitoring noise levels in the stunning environment may represent a useful approach for assessing pig welfare and for predicting variations in pork quality.