The Devon farmers at the centre of the bluetongue furore have defended their decision to import cattle from an at-risk country.

Gordon and Hazel Davis of Westcott Farm, Westleigh, bought 35 bulling Holstein Friesian heifers from a bluetongue-restricted zone in Germany. Eight later tested positive for the virus after being brought to Tiverton, Devon.

Son Mark Davis said he and his family were “gutted” by the test results and by the reaction of local people. “We have done everything correctly – our business relies on us doing the job properly and professionally and I’ve been slated pretty hard for it.”

Mr Davis said he thought the test may have picked up on antibodies generated after the cattle had received their first vaccination in Germany. To rule out a mix-up, he has paid for his own re-test and is awaiting the results.

DEFRA insists the initial test was accurate and detected the presence of the virus, rather than vaccine antibodies. But Mr Davis said: “The animals have shown no sign of the disease – they are milking well and are fit and healthy.”

The family bought the cattle for themselves and clients from Germany because of its TB-free status and a shortage of dairy heifers on the UK market. Germany has reported no cases of bluetongue this year.

Mr Davis said he bought the cattle through a well-regarded herd book society from high-health-status herds in a bluetongue low-risk area. All the animals had received one or two vaccinations. “We did everything we possibly could.”

Even so, some people have questioned the wisdom of importing animals that could be infected with the disease. Contributors to internet forums such as FWi Space have condemned the practice.

Frank Momber, vice-chairman of the National Beef Association, said: “If importers must bring in stock, they should protect their reputations – and their own cattle – by insisting on a vaccination certificate signed by a vet.”

But Andrew Butler of the south-west NFU said Mr Davis had done everything by the book, and it was a timely reminder for farmers to ensure livestock were vaccinated. “As long as you’ve vaccinated your stock, you have nothing to fear,” he said.