Sarah Stewart, whose family has run the Farmlife Centre near Thornhill for eight years, said disaster struck in March after Professor Hugh Pennington, who led the Government inquiry into the 1996 E-coli outbreak in Lanarkshire, said in a BBC interview that a farm environment was not safe for young children.

The result was newspaper headlines advising schools against taking groups to farms, after which visitor numbers plummeted by a quarter. The closure comes just after the centre’s most successful year when visitor numbers for 1999 reached a record 40,000.

Mrs Stewart, a former teacher, dismissed the danger as minimal. “Owning a household cat or dog, certainly coming into contact with dog fouling, carries the same or higher risks s a visit to a farm like this,” she said.

“We have to be careful not to bring up children in such a sanitised environment that they have no resistance to germs at all.”

Mrs Stewart also blamed “nanny state legislation” for adding to the problems, citing new food legislation. “You might as well be catering for astronauts,” she said.

The real losers, she says, would be young children deprived of opportunities to see and handle farm animals. “Do we really want to bring up a generation interested only in computers?”

The Royal Highland Education Trust, which aims to promote the countryside in the curriculum, has issued guidelines, which have been approved by the Health and Safety Executive and are designed to protect children visiting farms.

Jane Methven, the trust’s education manager, said there should be no cause for concern if these guidelines are followed, and children would gain considerable educational benefits from farm visits.