Foaming of a poultry house to euthanize large flocks in a short time is a relatively new idea, getting its beginnings at the University of Delaware in 2004. Recently it could be tested in a commercial size practical situation.
Early April University of Delaware Poultry Specialist George Malone was asked to euthanize a flock of turkeys at a farm in West Virginia. The turkeys were confirmed the H5N2 Avian Influenza (AI) strain on the farm. Could he please bring his equipment to foam the house for depopulation.
At hand for depopulation were four houses â€” two with 10,000 birds, one with 3,000 birds and one with 2,000 birds. Through this experience, Malone said a lot of lessons have been learned for bringing this application to the real world.
The foaming concept involves fire fighting-type foams, including high expansion, compressed air foam, Class A and other foams. Research discovered that the foam can be successfully used to euthanize birds.
The foam is placed in the houses by a couple of methods, including moveable foam generators, stationary foam generators and portable hose and nozzle lines.
These studies have shown that foams are comparable to the carbon dioxide polyethylene tent procedure in time-to-death in small groups. The foam is faster as group size increases. Adding carbon dioxide to the foam does not enhance its efficacy.
Based on corticosterone levels, the study also showed that the foams are no more stressful than killing the birds with the polyethylene tent method.
Malone said there was no evidence of drowning in any of the foamed birds. Foam caused an airway occlusion. The foam acts by physically induced hypoxia (shortage of oxygen).
With foam, consistency is critical to get the needed height to cover the birds and ensure death. Also if the foam bubbles are too big or too small, it will not work.
The benefits of this system are that the animals are more humanely euthanized with a quicker kill time and increased worker protection. The farm can move more quickly into composting of the birds.
The foam method for depopulation was recently approved by US Department of Agriculture.