A number of notable individuals hail from tiny Kosciusko, MS, with Oprah Winfrey and blues harpist Charlie Musselwhite heading the list. Kosciusko’s latest claim to fame may be controlled atmosphere stunning (CAS) technology for poultry slaughter. Unlike other CAS systems, the system developed by Kosciusko-based TechnoCatch LLC relies on oxygen removal rather than lethal gas injection, resulting in a kill that addresses both animal welfare concerns and human discomfort in one of the food industry’s most difficult work environments.
TechnoCatch is a business unit of JC Cheek Contractors Inc., a road-building family firm. Cheek became involved in food-related equipment development in the 1990s, when Hollis Cheek partnered with Cattaruzzi International, an Italian supplier of poultry processing equipment, to develop a mechanical chicken harvester. With the interest in animal welfare increasing, the TechnoCatch team began exploring alternatives to carbon dioxide for CAS. Developers reasoned removal of oxygen would produce the same results at a lower cost and without greenhouse gases. The concept had been applied on a limited basis worldwide but never in the United States, where the American Veterinary Medical Association (AVMA) long has considered decompression an unacceptable method of euthanasia. But that didn’t detour developers, who have worked closely with food scientists and veterinarians to develop their low atmospheric pressure system (LAPS). Over the course of several minutes, pressure in the chamber is lowered to about 5psi from the typical 14.7psi. Research on chickens’ stress levels was conducted in conjunction with prototype development, and the first commercial unit is up and running at Fort Smith, AR-based OK Foods Inc. A letter of no objection was issued by USDA’s office of New Technology Testing Approval in spring 2009, and the system is certified by the American Humane Association.
Overseeing development of LAPS is H. Randolph Cheek, vice president of JC Cheek Contractors and a principal in TechnoCatch. He is a business school graduate of Mississippi State University (MSU) with a major in risk management and insurance.
FE: When did development of low atmospheric pressure for stunning chickens begin?
Cheek: Preliminary discussions began nine to 10 years ago, after our collaboration with Cattaruzzi resulted in an alternative to hand-catching of birds at the farm level. I was in my junior year in college in 2004 when my father asked me to meet with Drs. J. Paul Thaxton and Yvonne Vizzier-Thaxton at MSU’s poultry science building. A live chicken was placed in a pot with a plexiglass top and a hose to suck out the air. We watched to see if this approach would effectively stun the chicken without causing pain or distress, and it worked.
The AVMA ruled decompression to be unacceptable based on rapid rates of oxygen removal that cause gas expansion in animals’ gastrointestinal tracts. But gases are not likely to be trapped in chickens’ abdomens, and the rate of oxygen removal is much slower in our system than in earlier versions. Cycle time in the chamber is four minutes, 40 seconds, which results in a slow, precise, irreversible stun.
FE: Carbon dioxide mixtures are used successfully to stun hogs and other livestock. What advantage does oxygen removal offer?
Cheek: The cost of CO2 alone is a problem. If it was used extensively in animal slaughter, the price per ton would go through the roof. Additionally, birds can sense CO2 because the gas burns their nostrils and throats. Birds don’t have a low-oxygen sensor.
Electrical stunning is judged by AVMA to be a humane slaughter method, though for the four to five minutes from the time live birds are dumped from a cage and then stunned and shackled, there is stress. One measure of this is the stress hormone corticosterone. Research shows that the level of corticosterone with LAPS is half that of electrical stunning.
FE: Is there pain associated with oxygen starvation?
Cheek: Initial tests using EEG and EKG readings in December in the Netherlands suggested no pain, based on brain function. We need to be able to answer all questions about the impact on the neurology of the birds.
Hypoxia is the cause of death with this methodology. Hypoxia can occur with loss of cabin pressure in an airplane, which is why pilots undergo training so they recognize the symptoms. A feeling of euphoria precedes unconsciousness in humans. It’s possible birds have a similar experience.
FE: How large is the system’s footprint?
Cheek: The OK Foods installation is in the back dock area and includes four chambers, with transport cages feeding into each. The overall dimension is about 60 by 60 ft. It’s a HIMP plant (HACCP-based inspection model project), with two high-speed lines. The four chambers can deliver up to 400 chickens a minute. We knew if we could make the system work at a HIMP plant, it would work anywhere in the country.
FE: What were some challenges in building the system?
Cheek: We had never built a conveyor before, and PLC programming for sequencing the cages was one of the bigger challenges. We started with a base program, but 10 times more code had to be written than was originally envisioned.
While the cages all are square in a computer design, they aren’t necessarily true or square or don’t roll perfectly in reality. Placement of prox switches and sensors to identify and resolve issues in the sequencing of the cages was a long process. Tracing problems could only be done on the weekend, for the most part.
FE: What changes occurred with the original system design?
Cheek: A year ago, the chamber held one transfer cage. To reach commercial scale, we had to accommodate two.
After consulting with [animal welfare expert] Dr. Temple Grandin, cameras were installed inside the chambers so plant personnel could identify a disruption that is resulting in pain. At Dr. Grandin’s insistence, the operator has no control, other than the ability to turn the system on or off. That stemmed from her work with cattle and pigs and the incidence of human error. Cattle are rendered insensible with a shot from a captive-bolt gun, for example. In welfare audits last year, operators failed to deliver a lethal shot up to 5 percent of the time, resulting in unnecessary suffering.
FE: Does LAPS impact product quality?
Cheek: Blood flow during exsanguination differs from electrically stunned birds, though blood loss volume was similar during testing. Breast meat quality is excellent, and decreased stress levels minimize problems such as pale, soft and exudative meat. Carcass quality is at least equal to electrical stunning. And unlike conventional slaughter, where fecal matter is released on the line, the birds evacuate their colons before entering the plant, which may have a positive impact on bacterial counts.
Wing damage occurs more frequently than with electrical stunning, though controls optimization has reduced the variance.
FE: Why are there higher levels of wing damage?
Cheek: With the onset of loss of posture, which is tied to unconsciousness and elimination of pain, the birds get on their backs, and wing-flapping usually occurs as they go into their death struggle. Because they fall on top of each other, wing damage can occur. Additionally, the birds’ wings are a lot more limber than with electrical stunning, requiring an adjustment to the mechanical picker. The damage is dislocations, not compound fractures.
OK Foods sought strict limits on the level of wing damage. The rate varies depending on the weight of the birds. OK Foods uses electric stunning for 20 minutes before shift changes. That establishes a baseline for comparison with LAPS. They said we can’t be more than 2 percent above the limb damage rate with electrical each day.
FE: How does LAPS impact workers?
Cheek: For workers, it’s a complete 180° in the operating environment. OK Foods used to have to bring in temporary workers in the hanging room every day. Now, turnover is just about gone.
Typically, the hanging room is dark, workers need protective clothing, and there’s lots of dust. With LAPS, the lights are on, there’s no dust, and the experience is less traumatic for both the birds and the workers.
FE: Do you see LAPS as mainstream or niche technology?
Cheek: It will become mainstream because of the interest in the welfare of the animals we eat.