Johannesburg - The National Council of SPCAs has described filming pigs that screamed in anguish and tried to escape from a pit, while being gassed before their slaughter at a Pork Packers abattoir on the East Rand. The Pork Packers abattoir supplies meat for Enterprise Food, which is owned by Tiger Brands. It also provides meat to some retailers, such as Woolworths. Woolworths confirmed with News24 on Monday that it receives meat products from Pork Packers. The NSPCA took footage at the abattoir in August last year and in June this year that shows the pigs screaming and writhing around while trying to get oxygen. According to them, this is because of the inhumane way of "stunning" the animals before their slaughter with carbon dioxide. This process involves caged pigs being mechanically dropped into a pit which is pre-filled with carbon dioxide. "After minutes of exposure to the CO2, the pigs suffocate as a result of the lack of oxygen. But until they lose consciousness, the pigs experience panic-like symptoms. "International exposés of this method of stunning pigs are well documented. This issue needs to be addressed urgently and directly," the NSPCA said. "It was confirmed that the time it takes for the pigs to become unconscious can be up to 56 seconds. This is considered to be unnecessary suffering before death." 'They believe they have done nothing wrong'NSPCA executive director Marcelle Meredith told News24 that they were planning on taking legal action against Tiger Brands. "We are involved in a lot of legal stuff - our lawyers have written to them. We have engaged with them and they simply don't believe that there is a problem - they believe they have done nothing wrong," she said. "What else are we supposed to do except approach the court? It will be for an interdict."Tiger Brands said it would send News24 documentation on Pork Packers later in the day.WARNING: SOME MIGHT FIND THE VIDEO DISTURBING: According to the NSPCA, Pork Packers is the only abattoir in South Africa to use gas commercially to "stun" animals for food production. "The usual or standard practice in abattoirs is to stun the pigs electrically, rendering them unconscious immediately. As a result, the animal feels no pain. This is commonly known as the pre-stunning process and forms the basis of humane slaughter of all factory-farmed animals."The NSPCA said Tiger Brands was approached in 2014 to invest in research to identify the best method of gas stunning. "They refused. Instead, Tiger Brands consulted with an international consultant as well as with the Department of Agriculture, Forestry and Fisheries to review their operating systems."The NSPCA said it later received information that the Tiger Brand's Kempton Park abattoir had allegedly improved its system with a reduction in the time the pigs suffered. "Obligated to verify the claim, the NSPCA endeavoured to witness the 'upgraded' procedure, but personnel were denied access. A warrant had to be obtained [in June this year] to gain entry and witness the gassing of pigs."This was where the most recent video was filmed. 'Our aim is to prevent animals from suffering'The society consulted international experts and got a scientific report from a researcher based in the UK, saying the use of carbon dioxide was not the most humane way of "stunning" pigs to render them unconscious prior to slaughter. “We didn’t only focus on the problem, but worked tirelessly to find a solution as our aim is to prevent animals from suffering,” Meredith said. "The NSPCA proposed changing the gas in the pit from a noxious gas, such as CO2, to an inert gas like argon. Argon or a combination of argon and CO2 would render the animals unconscious without the stress and panic of suffocation."The NSPCA said it held several meetings with representatives from Tiger Brands, Woolworths and the department of agriculture to replace the system with a more "humane" method. "This proposal was submitted to Tiger Brands and Pork Packers and was rejected."Woolworths told News24 it was aware of the allegations tabled by the NSPCA."Pork Packers supplies Woolworths with fresh and processed pork products," it said. "Woolworths cares deeply about the welfare of animals. We believe it is our ethical obligation to ensure that our suppliers treat the animals in our supply chain with respect and in the most humane way possible, and are committed to continuous improvement in all aspects of animal welfare."All suppliers are required to promote animal welfare by minimising any potential harm, stress or pain to animals, and adhering to relevant national and/or international standards for animal welfare. These standards are audited by independent auditors to ensure compliance."