An assessment of carbon dioxide stunning in pigs.

The vocalisation patterns of pigs subjected to stunning in 86 per cent carbon dioxide in a commercial abattoir suggested that narcosis began 30 to 39 seconds after the start of the immersion procedure. The spontaneous and reflex physical behaviour of the pigs after immersion indicated that they were effectively stunned, but the majority of the animals were not considered to be brain-stem dead. None of the carcases showed pale soft exudative meat.