Footage has emerged which claims to show the horrific conditions endured by 500,000 chickens that lay eggs for the UK’s largest egg producer and supermarkets.

Around 140 million eggs are laid each year at Walston Poultry Farm, prompting undercover investigators to obtain covert footage.

Investigators claim to have discovered the farm, which supplies eggs for Noble Foods’ Big & Fresh, breached animal welfare laws.

In the footage, chickens can be seen in cages stacked seven high (SWNS)

In footage taken at the farm in Blandford Forum, Dorset, chickens can be seen in cages stacked seven high and locked in sheds.

Big & Fresh, a brand of eggs from caged birds, is sold in most of the UK’s leading supermarkets, including Tesco and Asda.

Noble Foods said it has launched an internal investigation and audit.

Animal Equality, a leading international animal protection organisation, released the footage after obtaining it by placing hidden cameras at the farm.

Footage proves Noble farm is in breach of the Welfare of Farmed Animals (England) Regulations 2007, Animal Equality charity claims (SWNS)

They left one camera running for four days, and in that time the hens were checked only once.

Animal welfare law states that birds have to be checked “at least once a day” and inspections should be “sufficiently thorough to detect illness and injury of individual hens, and special attention should be paid to bodily condition”.

In the footage, dead hens can be seen lying in cages, and one dead bird was photographed in the same place for two consecutive days.

The footage proves that Noble farm is in breach of the Welfare of Farmed Animals (England) Regulations 2007, the charity claim.

One dead bird was photographed in the same place for two consecutive days (SWNS)

Dr Toni Shephard, the UK director of Animal Equality, said: “The pitiless practice of locking hens inside crowded cages inevitably leads to the frail, featherless birds and high mortality that we found on this farm.

“But the failure to even check on these poor, helpless hens once a day – as the law requires – shows complete disregard for them as living, feeling animals with fundamental needs.

“Consumers paying a premium for Happy Eggs will be horrified to learn they are indirectly supporting these cruel cages used on Noble Foods’ other farms. It is time for Noble to go cage-free across all of their brands.

“We wanted to show the conditions inside a typical caged hen farm.

“We know eggs in supermarkets will say from caged hens but for most consumers that doesn’t draw up the images to mind of what the practice looks like.

“They don’t picture the severity of the suffering.

“The images will be shocking to people, to see just how crowded those cages are and how severely the animals suffer from feather loss and the number of dead animals.

“For me, it’s the scale of the operation that is so shocking.

“There can be half a million birds on one farm but to drive past it you would have no idea, there’s no windows, no indication that these huge metal sheds contain living animals.

“Caging animals for their entire lives without fresh air, without daylight, never even standing on solid ground, that has got to be the most cruel form of farming that is currently practised in Britain.

“I’m very pleased the different agencies have committed to inspecting the farm, including Dorset trading standards and the British Lion code.

“They have both said they will be investigating the farm after getting our evidence, so we would certainly like to make sure the farm complies with at least the basic protection that farm animals have, to be inspected at least once a day.

“It’s going in the right direction, but too slowly for the animals that are suffering in these conditions.”

In the footage, dead hens can be seen lying in cages (SWNS)

A spokesperson for Noble Foods said: “Noble Foods takes the welfare of poultry on farms supplying the company very seriously.

“The egg industry and its customers require companies to be stringently checked by regular independent auditing procedures including spot checks via unannounced visits.

“All sites supplying Noble Foods are fully compliant with UK Government and European regulations on welfare of poultry.

“Having seen the report produced by Animal Equality, relating to our contract producer ‘Walston Poultry’ with whom we have a long-standing relationship, we have immediately launched an internal investigation and audit of the site highlighted.

“Separately, the farm will be visited, without notice, by the British Egg Industry Council responsible for the Lion Code of Practice, the officially approved scheme requiring egg producers to maintain the highest possible welfare standards and environmental controls.

“Our investigation into this matter is underway and Noble Foods remains committed and vigilant in demanding the highest standards from all its suppliers.”

Walston Poultry Farm did not respond to a request for comment.

According to their website, Walston supply eggs “as far afield as the Falkland Islands” and customers “include national retailers”.