Footage shown on ABC's 7.30 program which appears to show pigs suffocating after being stunned with carbon dioxide (CO2) gas before slaughter, a legal and widespread practice, has angered some pig farmers who say they have very limited choices when it comes to processing their animals.
Tammi Jonas runs a small-scale pig farm near Daylesford, central Victoria, and said the intensive nature of the pork industry and a centralisation of pig abattoirs to large multinationals had resulted in concerns for the welfare of Australian pigs.
Ms Jonas is the president of the Australian Food Sovereignty Alliance and said large-scale abattoirs prefer CO2 stunning because it allows for a higher number of animals to be killed in a day.
"We don't have a choice how our animals are slaughtered and we have a shrinking number of abattoirs available to us owned by a dwindling number of companies," she said.
"They call the shots and small-scale producers in particular have no say at all what happens in those places. We just don't have any clout.
"It's one of the reasons we're building an abattoir ourselves and why we think there should be small-scale abattoirs everywhere, to stop these poor welfare practices."
Productivity vs welfare
Ms Jonas said she disagreed with claims by the Australian Pork Limited and the Australian Meat Industry Council that CO2 stunning minimised pigs stress.
"The physical distress for those 20 to 30 seconds of gasping, feeling like they can't breathe," she said.
"The alternatives are really straightforward. There's captive bolt and electric stunning, and both of them are immediate."
Sarah Groom runs Homemade Healthy Happy Farm at Waitui on the New South Wales Mid North Coast.
"Am I happy with the practices? I don't know, because it's really hard to get on the floor of abattoirs in Australia," she said.
"That is where we've kind of been boxed into a system where pigs are being processed at large-scale abattoirs."
Best method
WA Pork Producers Association committee member Dawson Bradford runs a 1,400-sow unit at his farm at Narrogin, 200 kilometres south-east of Perth.
"CO2 stunning is the best method we have available at this time but industry is continuously looking for improvement and researching better methods."
"As soon as we can find better methods the industry will be only too happy to change over."
Market analyst and former central Victorian pig producer, Matt Dalgleish, said he believed it was likely the pigs seen in the footage illegally obtained by the Farm Transparency Project were reacting to the stress of being confined, rather than the CO2.
"If you were not exposed to pigs generally, I think you could look at behaviour and take it out of context and say that's terrible, the pigs are panicked and stressing out," he said.
"What we saw, that's escape behaviour, where they jump and squeal and carry on.
"That's a behaviour you see when they don't want to go up the ramp or through a yard that is a bit confined.
"Pigs can get very panicked and they're not being mistreated but some are just nervy pigs."
Mr Dalgleish said if the supply chain were altered to avoid CO2 stunning, costs would increase at the abattoir and the price of pork would increase.
Animal welfare scientist with the Alliance for Animals, Bidda Jones, said although other countries such as the United States use CO2 to stun pigs, the practice had been identified by the European Food Safety Authority as a "method that needs to be replaced".
"The industry seems to have made the decision that because this is only the last few moments of a pig's life that it doesn't need to do anything about it," she said.
Dr Jones did not recommend using captive bolt to stun pigs and said not enough research or investment had been done to upscale electrical stunning.
