The zones have been creeping through Yorkshire for a few weeks, eventually mopping up the remaining areas of North Yorkshire that were not covered earlier in the month.

But the impact of the ever-shifting zones on local auction marts has varied, with some virtually unaffected and others coping with disrupted trading for the second year in a row.

But after the zones were eventually extended to the whole of North Yorkshire and Lancashire some marts have returned to normal trading and reported good results.

One leading auctioneer questioned the decision to bring in protection zones gradually, saying the whole country should have been brought into the zone in one movement.

James Stephenson, auctioneer at York Auction Mart, said: "Wherever you have a market on the edge of a zone, trading has been disrupted, often substantially and quite unnecessarily.

"My view is that the whole of England and Wales should have been made a protection zone. The current method just seems to be shifting the problem ever northwards.

"This way animals could be vaccinated as and when they got it, and this would mean we would not have had markets disrupted and agricultural shows disrupted.

"It should be remembered as well that there will be no compensation for anyone involved."

Leyburn Auction Mart celebrated a return to normal trading after four months of restrictions. Company secretary Charmaine Fletcher said: "At last we are in the protection zone. There are still quite a lot of people near us who who could come and sell here. However we are now in the zone and everything seems to be going back to normal."

Skipton Auction Mart's general manager Jeremy Eaton reported that the annual show and sale of Mule, Masham and Continental-cross shearling gimmers attracted bumper entrants with prices averaging £82.87 for Mules, Texels £80.97 and Mashams £64.26.

He said: "Additionally, entry levels in our fortnightly store lamb sales have improved dramatically, with 6,000 sheep passing through the ring."

Defra's announcement this week that the Protection Zone would be extended to include Northumbria and Cumberland and up to the Scottish border some time after September 1 has brought some relief, but not solved all of the problems for auctioneers.

Andrew Pratt, chairman of Hawes Auction Mart, said many of its customers in those areas were currently prohibited from attending.

Mr Pratt said: "We have only just come into the Bluetongue Protection Zone, which is great as more of our customers who have been on the border can now come to the sales this autumn.

"But the border has been causing problems to the north, as many of the people we deal with in Northumbria and Cumbria have been unable to come in."

People could bring in animals but not take them out again if they felt the price was not enough.

He said it was good news that the zone was being pushed back but there was no indication exactly when that would be.

"We're just hoping that it will be before our main breeding sheep sale on September 15 and 16 - if it is then it will make a huge difference because we will be able to trade freely."