Air-powered stun gun proves effective for euthanizing piglets

Monday, February 20, 2012

Researchers are finding that farmers and stock people previously reluctant to euthanize animals are more willing to do it using the Zephyr gun they have developed

by MIKE MULHERN

An air-powered stun gun called the Zephyr could become the instrument of choice for pig farmers and stock workers to euthanize young pigs up to nine kilograms.

Tina Widowski, a professor in the department of poultry and animal sciences at the University of Guelph and the director of the Campbell Centre for the Study of Animal Welfare, is the principal investigator looking into the effectiveness of the Zephyr and its ease of use for stock workers and farmers.

"The Zephyr deploys a non-penetrating captive bolt powered by an air compressor. It's working extremely well," Widowski says. Her principal researcher is Teresa Casey-Trott, who is basing her master's thesis on the field research. She has euthanized more than 200 piglets and is close to ending field trials, which she says have gone well.

'For any euthanasia," she says, "you want to make sure that the animal is insensible immediately or rapidly at the start of the technique. So you want to make sure the animal is knocked unconscious, it is not aware of what's going on, is not feeling any pain or sensing any problem." She says the animals never regain consciousness and death is confirmed within a few minutes by cardiac arrest.

"This is a single-step method," Casey-Trott says, adding that the trials have been very successful on piglets just born and on into the early nursery stages up to about nine kilograms or 20 pounds. The gun was tested on piglets three days old in the first part of the two-year trial and is now being tested on animals three to nine kilograms.

The Zephyr is a modified brad nailer hooked up to a compressor. It was first developed to kill rabbits in 2004 by a team from the Ontario Ministry of Agriculture Food and Rural Affairs (OMAFRA) and the University of Guelph and was later modified to euthanize large turkeys. It had to be modified again to be effective on piglets.

Casey-Trott says that any compressor capable of holding a charge of 120 pounds per square inch (psi) will work. With the compressor she uses, once it is charged up, she gets about 50 shots before it begins to recharge.

The reception from farmers and stock workers has been positive, she says. "They are pretty apprehensive at first," she says, "because when I go out to do a trial, it really forces them to think about the fact that you are killing an animal." She says staff at farms, previously reluctant or unable to euthanize animals, are more willing to do it using the Zephyr.

The physical requirements are a Zephyr gun, an air compressor and a restraining device. They are looking for a manufacturer to produce the guns for widespread use and they hope to offer farmers a complete system.

"Our goal is to have an all-in-one unit with restraint device, compressor and gun just to make it easy and accessible in barn situations," she says.

The restraint device is a hammock or sling. "You pick up the piglets and put their four legs through," so they are suspended.

"It calms them," she says. "I think it's the sternal pressure or having their legs hanging. Or maybe it's the swaddling effect. They're really quiet."

Casey-Trott believes the gun would be most useful in farrowing barns, where you could euthanize piglets from birth all the way through weaning and into the early stages of nursery. Right now, she says, they have four Zephyr guns, all of them made at the university.

The alternative to the gun has been blunt trauma. "We know it's humane," Widowski says,  adding that they have tested blunt trauma and found it is effective. It involves taking the animal by the hind legs and striking its head against a concrete surface.

"The problem" Widowski says, "is that people hate doing that and they put off euthanizing animals after the animal has reached the humane endpoint because, up until now, there haven't been a lot of good options." She says people are reluctant to face the fact that, in any animal care situation, there are going to be injured or sick animals,

"It's very difficult, but it's a reality people face every day, particularly in farrowing barns."
Widowski says the reasons to euthanize piglets vary and can include low birth weight and failure to thrive or adapt. She says the animals suffer and they can also be an economic drag on an operation.

An extension of the current research is the preparation of a video and other training materials, which are being produced by Food & Farm Care Ontario, formerly known as OFAC.

Crystal Mackay, executive director, says the training materials will be made available to farmers and veterinarians. "If there is a problem or if piglets need to be culled," Mackay says, "we want it to be done quickly and humanely and this equipment allows for that."

Training will include information about signs of consciousness. "The video is a very practical way to show stock people, farmers and veterinarians what signs to look for to know the animal is insensible," Mackay says.

Food & Farm Care Ontario "is sponsoring the cost of the training materials and then we'll be partnering with Ontario Pork and OMAFRA to actually get the resources to the producers ," she says.

For Casey-Trott, the video is part of a scholarship program. "I am paired to work with Food & Farm Care Ontario and, as part of the agreement with them, I am helping to create some training materials."  BP