Blood parameters and corneal-reflex of finishing pigs with and without lung affections observed post mortem in two abattoirs stunning with CO₂.

摘要

In two pig abattoirs of different slaughter capacities, the stunning efficacy of CO₂ on finishing pigs with and without pneumonic lesions (observed post mortem) was reflected against the corneal-reflex and blood parameters (blood pH, pCO₂ and pO₂) from individual finishers. Stunning duration was 120s (abattoir A) and 90s (abattoir B), respectively. Pneumonia in finisher pigs is frequently observed during post mortem inspection, which may raise concerns about a delay of unconsciousness because of hampered gas exchange in the lungs. The aim of this study was to examine possible pneumonia consequences for stunning efficacy under commercial conditions. For that, corneal reflex, O₂ and CO₂ partial pressure in the blood as well as blood pH were measured in 2650 finishers from abattoir A and 2100 from abattoir B. The partial pressure of O₂ after stunning accounted to about 3kPa, the partial pressure of CO₂ was found at levels of about 24kPa in abattoir A (after 120s CO₂ exposure) and 17.5kPa in abattoir B (after 90s CO₂ exposure). In abattoir A, the blood pH was at 6.9, and at 7.0 in abattoir B. The corneal reflex was observed in 6.2% of pigs in abattoir A and 17.1% of pigs in abattoir B. A correlation between pneumonic lesions and blood status was not observed. However, for some individual farms, a significant correlation between pneumonia and corneal reflex was observed