Even though the numbers of cows found or suspected to have BSE in Britain has drastically fallen, there are still up to 150 found each month. Why, despite the cull and the feed ban, should this be? Environment correspondent Alex Kirby reports.

The number of cattle slaughtered as a consequence of the bovine spongifrom encephalopathy (BSE) outbreak in the United Kingdom is approaching four million.

Most of them have been killed as a precaution, not because they had actually developed BSE, or mad cow disease.

The Agriculture Ministry's Over Thirty Month Scheme has accounted for 3.5m animals. It is designed to ensure that cattle over that age are slaughtered and their carcases destroyed, as it is older beasts that appear to be at greater risk from BSE.

Another 77,000 cattle have been slaughtered because they had grown up with animals that fell victim, and had eaten the same potentially-contamined feed.

But by 1 October 1999, 175,634 animals had died or been killed, either because they were definite BSE sufferers or because they were suspected of being sufferers.

Downward trend

At the height of the epidemic, in 1992/1993, there were about 3,500 actual or suspected cases every month.

There are now about 120-150 cases a month, and some scientists think it possible that the total for 1999 will be fewer than 2,000.

The trend of animals dying or slaughtered shows a steep downturn:

• 1992 - 36,680
• 1994 - 23,943
• 1996 - 8,013
• 1998 - 3,178

One reason for the present distrust between the British and French Governments is France's insistence that there will be about 3,000 BSE cases in the UK this year (it has reported a total of 71 cases itself).

The reasoning behind the much higher French estimate is not clear. But some independent scientists are worried that 94% of cattle falling ill with BSE, or suspected of being infected, were born after the suspect feed was banned.

The ban, which prohibited the use in cattle feed of the remains of sheep, was introduced in July 1988. It was brought in because BSE is thought to have spread to cattle from feed including meat and bone meal made from sheep suffering from a similar brain disease, called scrapie.

Crucially, though, the ban was not enforced properly for years after its introduction. It remained a paper exercise.

Demoralised

Francis Anthony, a Herefordshire veterinary surgeon, is the British Veterinary Association's spokesman on BSE.

He told BBC News Online: "If the ban had been enforced properly from the start, I have no hesitation in saying categorically that we should be seeing only a few cases today".

"But that contaminated feed was being given to animals until at least 1995, and possibly a year later.

"The British have always been seen as honest. It is demoralising that the feed was in circulation for seven years after the ban was enacted.

"And the idea that the epidemic is being prolonged by maternal transmission - BSE passing from mother to calf - just doesn't hold up. We are simply not seeing that on the farms."