After requesting to visit their slaughterhouse, Vion in Boxtel agreed to give Eyes on Animals a tour of their plant where 10,000 pigs are slaughtered each day. Vion uses CO2 gas to render the pigs unconscious before being cut and bled-out. Unconsciousness using CO2 gas is not instantaneous. Scientific studies show that it can take up to 60 seconds (Rodríguez, P.; Dalmau, A.; Ruiz-de-la-Torre, J.L.; Manteca, X.; Jensen, E.W.; Rodríguez, B.; Litvan, H.; Velarde, A. Animal Welfare, vol. 17 Number 4, Nov 2008 pp 341-349). Dr. Temple Grandin says that a large factor depends on the genetic differences between the different breeds and cross-breeds of pigs being slaughtered. Signs of distress during CO2 stunning include lateral head movement, vocalization (screaming), gasping, and attempts to escape.
Despite the alternative method of stunning pigs with electricity being able to render pigs unconscious instantaneously, many plants are switching over to CO2. Meat quality is better (less chance of blood spots), but the industry also claims that the process leading up to the stunning process is welfare- friendlier. In electric-stunning plants the pigs are moved in a single file towards the electric prongs, whereas in the gassing system they can be moved in small groups. Eyes on Animals plans to release a film showing the behaviour of pigs prior and during electrical and CO2 stunning so that ethologists, veterinarians and the public can clearly see the difference and have the tools to discuss which system is more humane.
At Vion today we observed many pigs gasping, scream and jerk their heads during the time they were exposed to CO2. We counted 14-16 seconds by the time the pigs in the chamber were lying down and appearing unconscious.
The automatic doors that push the groups of pigs forward are set to move quite quickly, so that pigs not facing the right direction end up being shoved, falling, or piled on top of others. As well, once the automatic door reaches the end of the corridor it whizzes overhead the groups of pigs back to its original position, frightening the animals.
Eyes on Animals is not of the opinion that the process leading up to the gas chamber provides enough significant welfare advantages over the electric stunning system to justify the lengthier and more painful experience of inhaling CO2.
Unfortunately we were not allowed to film the CO2 stunning inside Vion for our film. They say they are transparent but want to avoid footage being misinterpreted.
We do appreciate however that at least Eyes on Animals was allowed to view everything on this day. We did note three positive points, namely that 1. the workers moved the animals calmly and didn't use electric prods 2. a pig in extreme stress and hyperventilating was separated and immediately killed where she lay and 3. that Vion offers woodchips for pigs arriving in a weak or sick state to lie on.
We would like to thank Vion for the tours of their plant and hope to work in a productive and sincere manner together.