Dutch poultry farmers are still flouting the rules, with one in four being issued with a fine or formal warning last year, according to food safety authority NVWA.

A random survey among 91 of the Netherlands 734 poultry farms found that 38 farms (42%) were in breach of one or more of the rules, the government agency said.

Animal welfare issues, such as overcrowding, a lack of straw and bad lighting, were a major issue. Farms also failed to keep a proper record of the slaughter weight of broiler chicken and report lesions to their feet, which they are required to do by law.

Millions of broiler chickens are slaughtered in Dutch abattoirs every year.

‘Plofkip’

Meat from extremely fast-growing chickens known as plofkip – which is fed to grow two kilos in six weeks – has been phased out from fresh meat departments in Dutch supermarkets.

However, many supermarkets still sell snacks that use plofkip, animal welfare organisation Wakker Dier says.