Menu items such as McNuggets, chicken sandwiches and salads come from birds that have been selectively bred over time to put on weight more rapidly than is natural, causing painful health problems, according to the campaigners.
They claim the world’s biggest fast-food chain failed to address the issue of the fast-growing breed when it issued a new animal-welfare policy last year.
The animal welfare campaigners have now launched a worldwide campaign, beginning with McDonald’s, lobbying against companies that use the breed in intensive farming systems.
The new guidelines that McDonald’s issued in October require suppliers to follow new standards by 2024 for raising and slaughtering chickens, including increasing the amount and brightness of light in chicken houses and providing birds with access to perches that promote natural behaviour.
The company also pledged to conduct trials with suppliers to measure the wellbeing of different breeds.
But the Humane League UK says the pledges still allow quickly growing breeds to be commonplace in factory farming systems.
The one billion “broiler” chickens raised for meat in the UK each year have been selectively bred over decades to prioritise fast growth and big breast muscles.
They grow so big so fast that their bones and organs cannot keep up, according to critics of intensive farming, who claim the weight of the birds’ upper bodies causes leg pain and lameness, sometimes collapsing under their own weight, while the pressure on their hearts means birds often die prematurely of heart disease.
When they are handled badly before transport or slaughter, their weak bones means their legs often break.
Broiler chickens account for 95 per cent of all land animals farmed in Britain, with animal charities also arguing the barren warehouses where they are reared are cramped and cruel.
The Humane League says today’s birds “have been made into genetic monsters that grow unnaturally fast and often cannot even walk. Their environment is crowded, filthy and devoid of anything related to a natural life.”
Pru Elliott, of The Humane League, said: “Despite claiming to invest in animal welfare, McDonald’s is showing resistance to change and lack of leadership on the issue of chickens reared for meat.
“McDonald’s uses free-range eggs and organic milk so why does it source chickens that have been bred to grow so fast their bodies can’t keep up? This doesn’t make sense, and ultimately chickens are suffering en masse because of it.
“Chickens are the most numerous farmed animal and suffer in the greatest numbers, so why are McDonald’s failing to make change where it really counts?”
A coalition of groups opposed to factory farming wants food firms to sign up to the “better chicken commitment”, a new set of standards that includes using breeds that grow more slowly, reducing overcrowding, providing better living environments and ending cruel slaughter practices. The standards go above and beyond the minimum legal requirements for poultry welfare.
Ms Elliott said changing the breed used was the crucial factor in curbing “unthinkable” suffering.
“Providing chickens with enrichments and improvements is meaningless until they change to breeds with better welfare, because the birds’ suffering is such that they can’t make use of them or appreciate them,” she said.
The Humane League has launched a worldwide campaign, called I’m Not Lovin’ It, to put pressure on McDonald’s.
A series of events in the UK included inviting passers-by to throw damp sponges at a volunteer dressed as the chain’s publicity character Ronald McDonald, who was put in stocks; activists dressed as him visiting the company’s headquarters; flashdancing in Leicester Square, London, and handing in a petition with 236,000 names.
Pret A Manger signed up to the better chicken commitment within four hours of the campaign’s being launched. Azzurri Group, which operates Zizzi and Ask Italian, has also signed up.
McDonald’s said it is committed to sourcing food and packaging sustainably.
“This includes continuing to invest significantly to raise welfare standards for the animals in our supply chain and undertaking research to increase industry understanding of the challenges that remain,” said a spokesman.
He said farms that rear its chickens must meet independently set farm assurance standards.
“In addition to this, for a number of years we have required them to provide enrichment objects for the birds to peck and perch on, as well as windows in their houses to provide natural light,” he added.
“We recently announced a Global Chicken Sustainability Advisory Council, a multi-stakeholder group including leading academics and animal health and welfare experts, global suppliers and NGOs. This group will provide deep expertise, diverse perspectives, and recommendations for evolving our chicken welfare and sustainability strategy across the world.”
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies