Johannesburg - The Pork Packers abattoir, which is in the crosshairs of the NSPCA over its method of gassing pigs before slaughtering them, has said its methods create less suffering for the animals. "Pork Packers believes that it is necessary to employ measures to avoid pain and minimise the distress and suffering of animals during the slaughtering or killing process. In so doing, we take into account the best practices in the field and the methods permitted under the regulations," it told News24 in a statement. 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 the 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 with carbon dioxide before their slaughter. This process involves caged pigs being mechanically dropped into a pit which is pre-filled with carbon dioxide.WARNING: SOME MAY FIND THIS VIDEO DISTURBING: Pork Packers told News24 that the two most common methods of commercial pre-slaughter of pigs were electrical stunning and CO2 "anaesthetisation"."Carbon dioxide partly acts by displacing oxygen so the brain cannot function and brain death ensues. It also has a direct anaesthetic effect which results in loss of consciousness more quickly than with some other low oxygen gas mixtures such as argon and nitrogen mixtures," it said. "While the industry acknowledges that all methods cause aversion, the use of CO2 anaesthetisation offers least aversion. This method provides less stress for the pigs, is preferred by animal welfare specialists globally and is used by over 800 authorised abattoirs internationally."Pork Packers said its abattoir has regular audits by the department of agriculture, forestry and fisheries.New technology ‘would be welcome’"In the most recent, Pork Packers scored 97% - a gold rating - for health and safety, 96% for slaughtering and had zero non-compliance issues. Previous audits provided similar results. Pork Packers has three independent part-time vets who visit the site daily to check on the procedure. "It said the NSPCA has no regulatory role and "while Pork Packers understands the role the body plays, does not believe that their demand is valid or rational or in the interest of the animals". "Pork Packers concurs that while CO2 is an improvement on electrocution, there is indeed some aversion to CO2 and therefore would welcome new technology which lessens the stress of stunning on the animals." Read more: Pigs scream in 'inhumane' gas pits before slaughter - NSPCA"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 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."Woolworths’s ‘ethical obligation’This was where the most recent video was filmed. 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."