Latest Sonoma County front in avian flu crisis: How exposed farm-raised birds are killed
As the spread of a deadly strain of avian flu casts a pall over Sonoma County’s poultry industry, and opponents of concentrated livestock farming aim for a November ballot initiative that would limit if not eliminate many of those operations, the lives of birds on local chicken farms have become a subject of scrutiny.
And so have their deaths.
At least one of the county’s poultry farms has used a controversial method to dispatch its flock following an incidence of the virus. After Highly Pathogenic Avian Flu was detected at Weber Family Farms — the largest Sonoma County farm yet to be infected by the bird flu strain — on Dec. 18, the company turned to a practice called “ventilation shutdown plus heat,” or VSD+, to put about 115,000 birds to death.
The use of VSD+ has skyrocketed nationally during the bird flu outbreak that began about two years ago, and the practice is accepted by the U.S. Department of Agriculture, California Department of Food and Agriculture, and American Veterinary Medical Association.
But it is criticized as inhumane by many agricultural veterinarians and some lawmakers, and is highlighted by animal welfare activists who cite cases they say show animal cruelty in the livestock and poultry industry.
“There’s no great method to do this,” said Crystal Heath, an East Bay veterinarian who is a founding member of the group Veterinarians Against Ventilation Shutdown. “But VSD is the worst.”
Heath is right about the lack of elegant options when it comes to culling a flock of chickens or ducks. In addition to VSD+, the most common methods are asphyxiating birds with carbon dioxide — either by injecting the gas into an enclosed structure or, more commonly, going cage by cage with a CO2 cart — and spraying them with a version of firefighting foam.
Smaller operations still use tried-and-true farm practices like “cervical dislocation” — snapping the neck — and gunshot.
“There’s nothing about what we had to go through that’s enjoyable,” said fourth-generation poultry farmer Mike Weber, co-owner of Weber Family Farms and a nearby egg facility, Sunrise Farms, that also had to kill exposed chickens. “You see the birds suffering, and you wish there’s something else we could do. There wasn’t.”
Ventilation shutdown with no additional components — that is, sealing up airflow in a poultry house, shutting off fans and waiting for birds to overheat and die — can take four hours or more to accomplish its somber task. And it does not always result in 100% lethality, a regulatory standard.
For those reasons, VSD alone is not recommended by the USDA. That’s where the “plus” comes in. It can be the introduction of either heat (raising the ambient temperature to 104-110 degrees, resulting in faster hyperthermia) or carbon dioxide (resulting in asphyxiation).
The government allows VSD+ because it can be deployed quickly, preventing birds at other farms from being exposed to the virus.
That is pertinent in Sonoma County, where 10 poultry operations, ranging from boutique duck farms to large egg-laying operations, have been hit by avian flu in just over two months. More than 1.2 million birds have been destroyed to prevent further contamination within the county’s nearly $50 million egg and poultry industry.
Ancillary businesses like fertilizer companies and feed mills are also being affected and the Board of Supervisors in December declared a local emergency amid the widening crisis.
Sarah Van Mantgem, the co-founder of Farm Animal, Climate & Environmental Stewards of Sonoma County, was unmoved, saying she was “heartbroken” when she learned a county poultry farm had resorted to VSD+.
“Avian influenza has been a known threat since 2015,” said Van Mantgem, who lives in Windsor. “Why have they not put plans in place to do the responsible thing and end the lives of their birds in a less cruel way?”
What sets VSD+ apart from other forms of depopulation, its critics say, is how long it takes the animals to die. Those other strategies may be gruesome in their way, but death tends to come within 15 minutes, if not instantaneously.
VSD+ takes substantially longer.
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