Tyson to KO fowl before slaughter

Within the next year, Tyson, the biggest US chicken company, will launch a pilot programme at two processing plants to use gas instead of electricity to stun birds before they are killed.

The plan "is a significant step forward for us in understanding if this is scalable," Justin Whitmore, Tyson's chief sustainability officer, said.

The project is part of a broader shift in production practices in the US poultry industry. Such changes generally increase costs.

In January, US chicken processor Pilgrim's Pride touted GNP's use of gas-stunning when it paid $350-million (about R4.5-billion) to buy the rival.

In GNP's system, birds are lowered into a sealed tunnel in specially designed modules where the amount of carbon dioxide gradually rises to 70% from 5%.

In minutes, the chickens pass out as carbon dioxide displaces the oxygen in the air.