Worried farmers have shut off their farms to all but essential visitors in a bid to keep the disease at bay.

Mike Miller, of Greville Hall Farm, Hinton-on-the-Green, who two weeks ago won the supreme championship at the National Holstein Show, has put down a double barrier of disinfectant on the drive and no-one is allowed near unless it is absolutely vital.

"You just do everything you can and then just hope and pray," he said.

"We are lucky in being some way off the road and surrounded by mainly arable land but who knows? I think this week is going to be vital in terms of how the disease spreads."

Cattle in Mr Miller's 103-strong pedigree herd are still inside which, he said, was a help, as was milk-tanker drivers spraying their wheels between each farm visit.

On the organic Chapel Farm, Netherton, Elmley Castle, Richard Steele has 800 ewes and several hundred lambs from the first lambing as well as 60-70 head of cattle, dairy followers and Welsh Black.

"Most of the sheep are inside and the rams and ewes living out have been moved away from fields with footpaths running through them," he said.

"We are trying not to get too rattled," Mr Steele added.

"At the moment it is not as close as it was in 1967 but it would not be as easy to close the farm down now as it was then because we have people in houses which were then occupied by farm staff."

He said: "The worry at the moment is that every day more information comes in which makes the situation look more serious."