BRITAIN has told its European Union partners that "mad cow disease could be passed from cows to their calves. The announcement is a new setback in its campaign to get the worldwide ban on its beef exports lifted.
Yesterday's revelation is likely to shake consumer confidence in beef even more, just as revelations about the transmissibility of the disease to other animals have sparked fears that the crisis could spread to other meat markets.
Scientists had previously played down the risk of cattle passing on Bovine Spongiform Encephalopathy (BSE) to their offspring.
But following a re examination of the issue, Britain's Spongiform Encephalopathy Advisory Committee (SEAC) has concluded that up to one in 10 calves born to mothers with BSE could develop the disease.
A study of 300 calves born to cows which later developed BSE indicated a transmission rate of 10 per cent if the calves were born within six months of clinical symptoms appearing in the mother. Cows carry the BSE agent for five years or longer before these symptoms appear.
Over this longer period, SEAC said, the transmission rate would be one per cent. This figure, however, supposes an insignificant rate of transmission in animals born more than six months before symptoms appear in the mother.
This was not established by the study, which covered only calves born within 13 months of the onset of clinical symptoms.
The revelation is thought likely to put paid to London's hopes of winning an exemption from the beef ban for newborn calves by the end of this year.
The EU's standing veterinary committee agreed yesterday to refer the new BSE evidence to two specialist scientific advisory committees before discussing the need for further health or slaughtering precautions.
The Agriculture Commissioner, Mr Franz Fischler, however, raised the prospect of extending the British slaughter programme and suggested that the development could complicate the phasing out of the export ban.
In a letter to the British farm minister, he asked that Britain reappraise its selective culling plans, which are the centrepiece of its efforts to bring down the rate of BSE infection and get the trade boycott removed.
He also said that the "framework" for the step by step lifting of the ban agreed in June by EU leaders might have to be reassessed.
Senior veterinary officials of the European Commission suggested that implementation of the slaughter plan would have to be delayed until October at the earliest. They speculated that lifting the ban on exports of embryos or calves, which Britain hoped would be among the first to resume, would be particularly affected.
Chief veterinary officers were meeting to discuss the risk of BSE spreading to sheep and goats. But instead they used the meeting to subject the British representative, Mr Keith Meld rum, to close questioning on the latest findings - in particular the British claim that the rate of infection via maternal transmission could be as low as one per cent.
EU officials said afterwards that there was concern that the British eradication strategy was essentially based on tracing and targeting high risk animals - those born at the same time as BSE cases - but that this plan did not factor in maternal transmission.
"We are assuming this means many more animals will have to be slaughtered, but it is too early to say," said one.
Mr Meldrum denied that the eradication plan was now "off the rails" and flatly dismissed any new threat to human health.
He said the government accepted it would have to "re evaluate" its strategy for the eradication of BSE, but that this did not mean the plan was invalid.
Meanwhile, veterinary officers responded sceptically to the commission's plan to ban the offal, spinal cord and brain from sheep and other grazing animals.
The proposal follows new evidence that sheep could potentially be infected with BSE, rather than the similar 250 year old disease, scrapie, which is not considered a threat to human health.
Experiments in which sheep were given BSE by being made to eat contaminated feed also showed maternal transmission.
. Research published in Washington today adds weight to the theory that the mysterious prion protein is behind BSE and CJD.
Proteins with defective traits similar to the prions thought to cause mad cow disease could pass on their defects to proteins in neighbouring cells, an article in the journal Science says.
"This validates the concept of the prion in mammals," University of Chicago geneticist Susan Lindquist said of her findings.