MEASURES to keep poultry and captive birds indoors to protect them from a dangerous form of bird flu have been extended until the end of February - just days before it would prevent produce being sold as free range.

The "prevention" zone which has been imposed across the whole of England to protect against the highly pathogenic H5N8 avian flu strain in wild birds has been extended until February 28, government officials said.

It comes after the disease was confirmed in a back yard flock of chickens and ducks in Carmarthenshire on January 3, while a turkey farm in Lincolnshire suffered an outbreak before Christmas.

The strain of bird flu has been circulating in wild birds in Europe for some weeks and has been found in wild birds in Britain.

The prevention zone requires keepers of poultry and other captive birds to continue to keep their birds indoors, or take appropriate practical steps to keep them separate from wild birds.

That means higher costs for farmers of free-range birds, although the NFU is keen to highlight that they are still high-welfare animals.

When the restrictions were first introduced in December, free-range poultry farmers in Dorset and the New Forest told the Daily Echo that they had experienced “difficulty” keeping some birds indoors.

Farmers are able to retain their free-range status for a 12-week period of confinement. The new extension ends at the start of week 12, and it is not clear what would happen to free range producers should it be extended further.

Although the flu strain is much more virulent than previous strains and has a higher mortality rate, the risk to public health from the disease remains very low, Public Health England said. The Food Standards Agency said bird flu did not pose a food safety risk for consumers.

Chief veterinary officer Nigel Gibbens said: "The prevention zone means anyone who keeps poultry such as chickens, ducks and geese, even as pets, must take action to stop them coming into contact with wild birds to protect them from avian flu.

"Birds should be moved into a suitable building, or if that isn't possible owners must take sensible precautions to keep them away from wild birds, like putting up netting to create a temporary enclosure and keeping food and water supplies inside where they cannot be contaminated by wild birds.

"Even when birds are kept indoors a risk of infection remains so keepers must also practise good biosecurity, for example by disinfecting footwear and equipment and washing clothing after contact with birds."