Free-range eggs have disappeared from supermarket shelves in the UK as hens continue to be held in lockdown due to the country's largest ever bird flu outbreak.
From Monday, eggs from hens which are usually free-ranging will have to be labelled as "barn-eggs".
Bird flu restrictions were first introduced last November and were further strengthened on November 29, when a housing order was brought in. Since then farmers have had to keep their birds indoors to limit the spread of the disease.
Farmers were allowed to keep the free-range label on their eggs for 16 weeks, but this government grace period has expired, and eggs cannot be labelled free-range until hens can go outside again.
What is a free-range egg?
According to the RSPCA, free-range eggs come from birds that enjoy unlimited access to outdoor pastures during the daytime. Currently eggs cannot be classed as free-range because the birds are kept indoors permanently.
In Great Britain, supermarkets are expected to make the change clear to customers with signs in stores, and shoppers may notice stickers on egg packs showing the words "barn eggs".
What has been the impact on farmers?
Aimee Mahony, chief poultry adviser at the National Farmers' Union, described the situation as "an incredibly difficult time for all bird owners", adding that "vigilance remains vital".
"Poultry farmers continue to do all they can to ensure the health and welfare of their flocks, including following stringent biosecurity measures and adding additional enrichments to the bird’s environment such as pecking blocks and dust baths", she added.
The UK's Chief Veterinary Officer, Dr Christine Middlemiss, told ITV News the biosecurity measures that had been imposed were paramount because if birds became infected they would need to be culled, which would have "a devastating impact for those companies affected".
Andrea Martinez-Inchausti, Assistant Director of Food at the British Retail Consortium, said retailers would "continue to support British farmers".
What is bird flu and can it infect humans?
Bird flu, or avian influenza, is an infectious type of influenza that spreads among birds. In rare cases, it can affect humans, according to the NHS.
The risk to the general public's health is very low, the UK Health Security Agency said.
The Food Standards Agency has said that on the basis of the current scientific evidence, avian influenza poses a very low food safety risk for UK consumers. Properly cooked poultry and poultry products, including eggs, are safe to eat.
A spokesperson for the Department for Environment, Food & Rural Affairs (Defra) said the government would continue to provide support for the poultry sector throughout this "challenging time".
"We have worked closely with the sector and retailers to implement these changes as smoothly as possible", they added.