Use of liquid carbon dioxide for whole-house gassing of poultry and implications for the welfare of the birds.

The use of liquid carbon dioxide (CO(2)) was evaluated as a means of culling a flock of five-week-old pullets in situ. It took five minutes and 20 seconds for sufficient liquid CO(2) to be injected (3.24 tonnes) to achieve the target concentration of 45 per cent CO(2). Although very low ambient temperatures were recorded (below -80°C) during gassing, on the basis of postmortem reports and other data it is inferred that the birds died within minutes of exposure to the gas and before experiencing the extremely low temperatures recorded in the house.