Thursday, October 21, 1999 Published at 11:33 GMT 12:33 UK
Stunning techniques raise BSE infection fear
Government advisors say current practices are OK
By Environment Correspondent Alex Kirby
Methods used in abattoirs to stun cattle before they are slaughtered can spread very small amounts of brain tissue around their bodies, according to UK researchers.
Their work, reported in the magazine New Scientist, renews concerns about the safety of beef, at a time when the UK Government is trying to persuade France and Germany that its beef poses no risk to health.
This is a precaution against the possibility that some infected animals could arrive at an abattoir without showing any symptoms of the disease. But there may still be a problem, because of the need to stun animals before slaughter.
The usual procedure entails stunning them by shooting a bolt into the brain from a captive bolt gun. After this, they are hung up and their throats are cut so that they bleed to death while unconscious.
But researchers led by a veterinary scientist at the university of Bristol, Haluk Anil, say the stunning process can allow fragments of brain tissue to enter the jugular vein. And as the animal's heart continues to beat for several minutes after stunning, these tiny pieces could, in theory, travel anywhere throughout its body.
One type of gun, which is used in the US and in some European abattoirs, but not in the UK, shoots a hollow bolt which is cleared of brain tissue with a blast of air while still in the animal's head. Anil and his team found that this type caused brain particles to turn up in the jugular veins of 4 out of fifteen slaughtered cattle.
They have no evidence that the guns by themselves cause brain tissue to reach the jugular. But in about 70% of UK abattoirs the cattle are "pithed" after being stunned - a process in which a metal bar is thrust into the hole in the skull and moved back and forth to destroy the brain tissue.
The head of veterinary services at the UK Meat and Livestock Commission, John Pratt, says that if the research results are confirmed, abattoirs may have to consider different ways of immobilising animals.
Australia uses an electric current instead of pithing, but under the UK's animal welfare regulations this would not be allowed. The Spongiform Encephalopathy Advisory Committee, which advises the UK Government, has examined the researchers' preliminary findings and has decided that there is not yet enough evidence to alter current slaughterhouse practices.