Meat for thought

' stunning ', a method commonly used to prepare cattle for slaughter, could lead to "mad cow disease" in people, says a consumer health group in usa . Many scientists believe that a fatal brain disease called Bovine Spongiform Encephalopathy ( bse ) is caused by eating central nervous tissues, such as the brain, of infected animals. Meat packing plants take precautions to remove the brain and spinal cord from edible meat to avoid such complications. But researchers say that stunning might spread those tissues throughout the animal's body before it is butchered.

Slaughter houses use the decade old practice of sending a power-driven plunger through the animal's skull to render it brain dead. During the process, a plunger with a blast of air, is used to drive particles of brain matter through the animal's circulatory system.

Last year, researchers at Texas a & m University, usa, announced that they had found brain tissue in the lungs of nearly five per cent of cattle that had been stunned. The meat industry, however, says the findings do not have any bearings on public health in the us as lung tissue is not commonly eaten there. But the research by the team at Texas and the Canadian government's food inspection agency found bits of brain matter in liver and other parts of the animals' bodies as well.

According to industry estimates, the more forceful pneumatic method of stunning is used for 75 per cent of the slaughter and it processes more than 50 heads per hour. In a review of stunning procedures, Temple Grundin, assistant professor at the Colorado State University, usa, suggests that the pneumatic process increases the probability of contamination, especially when the creature is stunned more than once.

An outbreak of the disease in British cattle during mid-1980s, caused the deaths of more than a dozen people. If bse were to appear in the us, stunning could be a route for its spread from cows to human, says David Schardt, nutritionist of the us based Center for Science in the Public Interest.