The British Hen Welfare Trust has been forced to let 12,000 hens go to slaughter due to the threat of bird flu.Defra announced an Avian Flu Prevention Zone on 6 December for 30 days requiring all captive poultry to be kept indoors. The prevention zone was subsequently extended on 4 January until 28 February. Defra’s announcement means it is now illegal to hold any poultry gathering or to allow hens to free range.As a result around 12,000 hens which were due to be collected by the British Hen Welfare Trust in December, January and February have now gone to slaughter.'Difficult time'Jane Howorth MBE, charity founder, said: “We are best known for saving the lives of thousands of hens intended for slaughter so this is a difficult time for us. However, we take pride in acting responsibly and agree that Defra’s decision to extend the prevention zone to help protect national backyard and commercial poultry was the right one.”“Everything we do as a charity revolves around hen welfare so we are greatly saddened that 12,000 hens didn’t get their chance to enjoy a free range retirement, but we are looking forward to March when we hope that thousands will be able to enjoy the spring sunshine for the first time.”“We must thank our supporters who have been understanding and continue to patiently wait for their hens, as the hens themselves are patiently waiting for their chance to become family pets.”'Illegal to allow birds outside'The charity reminds hen keepers that the latest outbreak of Avian Flu was found within a backyard flock and that it is currently illegal to allow birds outside.The charity urges everyone keeping backyard hens to remain within the law and to protect their birds by keeping them under cover. The Chief Veterinary Officer for Wales confirmed Avian Influenza H5N8 in a back yard flock of chickens and ducks on premises in Pontyberem, Carmarthenshire. Prior to confirmation it was decided to cull the birds on strong suspicion of disease.The very same strain of the virus has also been found in a wild duck in Llanelli on 22 December, a turkey farm in Lincolnshire on 16th December and cases in wild, captive or domestic birds in many European countries, the Middle East and North Africa.