Foam depopulation

[9] In the 2015 H5N2 outbreak in the US, foaming was the primary method used to kill poultry en masse with it employed at 66% of locations.

[10] However, since 2019, foaming has increasingly been replaced in the US with ventilation shutdown, a controversial method which relies on suffocation and heatstroke after shutting off airways into a building.

This led to a backlog in slaughtering—leading to many locations using foaming or ventilation shutdown to mass kill farm animals outside of the typical slaughtering process.

[5] Concerns include the pain felt during suffocation and the stress or other effects on stray survivors seeing those who have died around them.

For instance, the Japanese Ministry of Agriculture, Forestry and Fisheries has purchased equipment for foaming that can be issued out.

Photo zoomed in showing primarily dead turkeys with some foam visible on them. A few turkeys are alive and walking around the ones who are not
Aftermath of foam depopulation being used on a flock of turkeys with a few still alive, as often occurs.