The federal government has erected an elaborate food inspection system, replete with double and triple checks, to ensure that animals on the way to slaughter are treated humanely and their meat is safe to eat when it leaves the plant.
The law requires slaughterhouses to create their own plan that identifies and addresses safety concerns. It mandates that U.S. Department of Agriculture food inspectors are onsite whenever animals are being killed. In most cases, USDA veterinarians are also supposed to be at the plant to supervise the inspectors.
The USDA is now alleging that Rancho Feeding Corporation, the Petaluma slaughterhouse in the throes of a massive recall of beef and veal, "intermittently circumvented" that system.
That would have been both difficult and very foolhardy, experts say.
"It's hard to believe that in this day and age they could be that dumb," said Temple Grandin, a Colorado State University animal sciences professor who consults with companies including McDonald's, Wendy's and Whole Foods Market on slaughter practices.
A Rancho co-owner has denied the USDA's assertion that the slaughterhouse bypassed the inspection rules.
As the system is designed, slaughterhouse managers must come up with their own safety plan, known as a Hazard Analysis and Critical Control Point program, or HACCP. But federal inspectors must make sure plant managers and employees are carrying out the safety measures identified in the plan. Also, inspectors have separate duties regardless of the HACCP.
"The role of the USDA inspector is to make sure they follow their own HACCP plan, and the inspectors are still doing visual inspection to make sure livers and things like that are healthy," said Grandin, who wrote the American Meat Institute's slaughter guidelines.
Under USDA guidelines, the first point of inspection is when cattle arrive at the plant in a truck. USDA inspectors are there to monitor the animals as they are unloaded, making sure they have ramps, aren't slipping or falling, and show no signs of illness.
After some time in the holding pens, often overnight, the cattle are given what is known as an ante-mortem inspection. The USDA inspector checks the cattle, while they are standing, for signs of disease and makes sure they have shade and water.
A pre-operation inspection is then performed. Inspectors check the kill floor for contaminants such as blood, fat or hair.
The cattle are then brought one at a time into a high-walled, concrete enclosure called the "knock box," where a bolt gun that doesn't penetrate the brain is fired between the animal's eyes to render it unconscious.
That is one point at which inspectors are not required to be present, although they must still be on the plant premises, Grandin said.
The animal's throat is then slit and it is hung from one or both hind legs to bleed to death, usually in three to four minutes.
What is known as the disassembly process then begins: the animal's head and organs are removed, and the skinned carcass is split in two.
Throughout, the USDA is required to have eyes on the work, checking the animal's organs, including eyes, heart, cheeks and head, for signs of diseases such as cancer, and making sure the digestive system is not punctured.
"The inspector is there the whole time," making sure nobody is deviating from the HACCP," said Caleb Sehnert, manager of the UC Davis Meat Lab slaughterhouse, a federally inspected facility.