It's not rocket science, but proper procedures dealing with the shackling of hogs in pork processing plants needs to be addressed. Points that should be discussed involve worker safety and ergonomics.
Obviously, kicking and resisting hogs can pose danger for line workers who are attempting to shackle them. But those hogs would be well relaxed if they were properly stunned.
The most fitting stunning technique, which would lead to safe shackling, is the use of carbon dioxide to induce animals senseless, a supplier says. "When pigs come out of a CO2 stunner, they are completely relaxed and limp, and they are not kicking," the supplier notes. "They can be easily shackled. CO2 stunning is probably the biggest improvement that can be made in terms of shackling and worker safety."
The European method
In Europe, CO2 stunning is the norm in pork plants, the supplier says. But the procedure is not as well accepted in the United States. It is more expensive than electric stunning. Ironically, CO2 stunning was practiced in U.S. plants in the 1950s. Normally, hogs must be shackled and stuck, or vice versa, within 10 seconds of stunning. If not, meat can be damaged by rising blood pressure. With CO2 stunning, quick shackling or stunning is not as big of an issue.
"With CO2 stunning, you can wait 30 seconds and there's no problem because the blood pressure of the animal is not rising," the supplier insists.
Workers at Milan, Mo.-based Premium Standard Farms electrically stun pigs, stick them and then shackle them. The animals aren't kicking because they are already dead.
Other pork plants, which are accustomed to stunning, shackling and then sticking, are adopting the technology used by Premium Standard Farms, experts says.
Collette Schultz Kaster, director of technical services for Premium Standard Farms, says stunning and sticking before shackling is good for two reasons:
-- It decreases the time interval between stunning and sticking, and decreases the chance of muscle disruption, both crucial elements to meat quality,
-- The procedure is safer for employees, who don't have to deal with frantic animals.
Shackling methods
Basically, there are two shackling procedures, captive and loose. Captive shackling has not changed much over the years, but some experts agree that it remains the best option available.
With captive shackling, a worker stands by the shackling table, slips a pig's leg into the chain and tightens the chain on the pig's leg. The process is repeated continuously by an employee. Most plants with high-speed lines install captive shackling machinery, a supplier says.
Loose shackles are part of a conveyor and are stacked on a tube. A worker slides the shackle forward, puts the chain around the foot of the animal and pushes the shackle into an elevating conveyor, which lifts the shackle up and the pig up to conveyor height. The worker then moves on to another tube.
"The advantage of having loose shackles is that one pig is indexed into each hook on the scald conveyor," a supplier points out. "That means every space on the scald conveyor is filled and workers don't have to scramble to try to get every shackle filled."
With loose shackles, line workers can pace themselves. The worker does not have to match a pig to each shackle.
The same can't be said of captive shackling. Shackles will pass by and if a line worker is not ready, the shackles will continue on. "The shackle will travel empty through the bleeding and scalding areas," the supplier says.
But experts say loose shackling can't be utilized in high-speed lines. The pace would be too fast for the system.
"It's more labor intensive to have loose shackles in higher-speed lines," the supplier says.
Low-tech improvements
Some packers are turning to strategies for ergonomic improvements that have nothing to do with an equipment upgrade.
An engineer points out that companies are strategically selecting people to be employed on shackling lines. A worker's height and endurance has plenty to do with the job at hand.
"The shackling table is not adjustable, so you don't pick a 6-foot-5 man to work on a 30-inch tall table," the engineer says.
Several companies are employing women, who are under 5-foot-8, on the lines. Employees applying the shackles on hogs in a pork processing plant should remember at least one rule: pay attention to duties. Shackling can be a dangerous job. An employee who is not paying heed to his or her duties is asking for trouble.
All the training in the world won't help an unattentive employee. For instance, a spokesman for a shackling conveyor supplier says line workers who don't pay attention to the conveyor operation could end up getting caught in the machinery.
"Employees still have to practice common sense, no matter how well they are trained," a spokesman for Premium Standard Farms says