There are around 75 abattoirs that slaughter pigs in Australia.
Eighty five per cent of pigs are slaughtered at seven export abattoirs across Australia. These process pigs for both export and domestic consumption. The remaining 15 per cent are slaughtered at a large number of small, mostly multi-species domestic abattoirs. These carcasses are only sold into the domestic market in Australia.
All pigs arrive at the abattoir on a truck especially fitted with misters that keep the pigs cool in hot weather. Pigs often arrive early in the day for slaughter on the same day.
Pigs are moved quietly and in small groups to the CO2 chamber. This reduces their separation anxiety, is closer to their natural behaviour and reduces pre-slaughter handling stress in comparison to moving in a single file. The less stress the pig is subjected to the more effective the CO2 stunning.
The main welfare advantage of CO2 stunning is that it reduces the risk of human error. CO2 also has an analgesic effect, which results in loss of consciousness more quickly than other gas mixtures.
The main disadvantages of CO2 stunning is that it does not induce instant unconsciousness and exposure to high concentrations of CO2 may not always work if pigs are stressed.
Some abattoirs also have boning rooms and further processing facilities while others simply slaughter and dress the pig.
Australian governments are currently re-writing the standards and guidelines in relation to abattoirs.