Strict controls aim for BSE-free herd

The bovine spongiform encephalopathy story has its roots in Britain in the 1970s, when despite a warning from the Royal Commission…

The bovine spongiform encephalopathy story has its roots in Britain in the 1970s, when despite a warning from the Royal Commission on Environmental Pollution the rendering industry brought in changes to save money.

These involved a drop in the heat treatment and duration of heat treatment in the production of meat and bonemeal and a withdrawal of a chemical called lye which had been used on the carcasses of sheep infected with scrapie.

Scrapie, which occurs in most European countries but has a very high incidence in Britain, is a disease in sheep similar to BSE. It affects the central nervous system.

By 1982 vets in the south of England, where the dairy farms are concentrated, began to notice that cows were suffering from a disease similar to scrapie in sheep.

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In November 1986 BSE was identified by the Central Veterinary Laboratory in London as a disease in its own right and the EU member-states were informed through the standing veterinary committee.

In April 1987 the British Ministry of Agriculture set up a study of 200 herds to see how the disease was transmitted. By that stage hundreds of cows were suffering from the disease.

The initial reaction in the UK in July 1988 was to ban the feeding of ruminants with meal containing ruminant-derived material, and in 1989 infected animals were banned from entering the food chain.

In February 1989, when there were more than 10,000 cases of what became known as Mad Cow Disease, a Royal Commission of Inquiry into the matter said it was unlikely that BSE would have any effect on human health.

The first cases of BSE occurred in Irish herds in January 1989 and controls were introduced which had been put in place in Britain. Most of the animals with the disease in the Republic had been imported from Britain or fed on imported meat and bonemeal.

Seven years on there have been 208 cases of the disease here in a herd of seven million, whereas in Britain there have been more than 171,000 cases in a herd of nearly 12 million.

Ireland avoided a greater degree of infection because it did not change its system of rendering meat and bonemeal at the same time as the British and because the level of scrapie infection is virtually nil in the Republic.

Nevertheless the Republic cannot claim to be BSE-free in and, ironically, at a time when the British appear to be getting on top of the problem, our figures seem to be rising.

Between 1989 and 1995 there were never more than 19 cases of the disease, but in July 1996 there was a dramatic increase in recorded cases. By the end of 1996 there were 74 known cases of BSE in the Republic.

Why did this happen? No one is sure, but the finger of suspicion is being pointed at the continued feeding of meat and bonemeal to cattle which may have been contaminated.

While the original cause of the disease may have been feeding infected sheep brain in meat and bonemeal, it now appears possible that many cattle infected with BSE were being rendered and, despite regulations banning it, some farmers continued to feed the banned material.

It continued to be legal to feed ruminant-rendered material to pigs and poultry, and while poultry feed may have been illegally fed to cows, there is also plenty of evidence that there was contamination of feed at compounding plants which mixed feed for both redmeat and whitemeat supplies.

Scientists now know that very small quantities of BSE-infected material can cause the disease in cows, and this is thought to be the likely reason figures are rising.

Earlier this bear the Government brought in strict controls on the meat and bonemeal sector and purchased all the remaining meat and bonemeal.

It did this on condition that the rendering plants here re-equip their facilities and bring them up to EU standards. It also decreed that only one rendering plant could manufacture and then store meat and bonemeal made from the most at-risk organs of cattle and sheep.

The skull, brain, eyes and spinal cord of all cattle and sheep are called specified risk material (SRMs) and must now be processed and kept out of the animal food chain.

It could take some years - BSE has an incubation period of up to seven - before the benefits of these controls will be seen.

Meanwhile, Ireland can boast that it has the strictest controls on BSE in Europe and the most expensive - we slaughter all animals in a herd where infection is found - and we can look forward to a time when we can boast that the Republic is BSE-free.