According to the BBC, millions of dead chickens sold in UK supermarkets had skin burns (known as “Hock burns”) from having lived in contact with ammonia from their own excrement, and this problem can be seen in a third of birds in some major supermarkets.

After asking the ten biggest UK chains about the presence of dead chickens with hock burns in their aisles, the Co-op and Aldi reported the highest rates but five supermarkets did not release data. Hock burn is associated with birds kept in crowded conditions and is a result of prolonged contact with dirty and wet litter, typical of many factory farms. 

Kate Parkes, the farm bird specialist at the RSPCA, told the BBC that hock burn was “a concerning health issue and, sadly, too common in many intensive farm settings” and that the risk of hock burn “is significantly higher when birds are poorly managed, genetically selected to grow very fast or reared in overcrowded conditions”.

The animal welfare organisation Open Cages investigated the supermarket Lidl (one of the stores that did not provide data to the BBC), with volunteers checking more than 500 whole chickens on shelves at 22 Lidl stores in nine UK towns and cities between September and November 2023. They found that 74% of the bodies of chickens they checked had had hock burns when they were alive. Connor Jackson, co-founder of Open Cages, said hock burn was “one symptom of a much larger problem… source chickens raised in heavily-crowded sheds, bred for extremely rapid growth, and this is routinely causing chickens immense suffering.” A spokesperson for Lidl said, “The figures provided by Open Cages strongly conflict with our own data, which is lower than industry figures publicly available,” but the store declined to share its actual hock burn figures with the BBC.

“Originally from Catalonia, but resident in the UK for several decades, Jordi is a vegan zoologist and author, who has been involved in different aspects of animal protection for many years. In addition to scientific research, he has worked mostly as an undercover investigator, animal welfare consultant, and animal protection campaigner. He has been an ethical vegan since 2002, and in 2020 he secured the legal protection of all ethical vegans in Great Britain from discrimination in a landmark employment tribunal case that was discussed all over the world. He is also the author of the book, ‘Ethical Vegan: a personal and political journey to change the world’.