Gas anaesthesia for pigs : expert feedback from a slaughterhouse fitted with the CO2-based group-anaesthesia system

The physical and chemical characteristics of pork produced by an abattoir using the back-loader carbon-dioxide stunning system were studied. Initial pH decline was relatively slow, indicating relatively low stress levels before slaughter. Despite this, average glycolytic potential of the semimembranosis muscle was also relatively low. Ultimate pH was normal with respect to literature data and glycolytic potential and was not related to blood pH. Glycogen levels were not correlated with urinary adrenaline levels, indicating that other factors are also implicated.