In a valley in rural Herefordshire, near the village of Kington, four industrial sheds lie partly covered in trees, with an apple orchard on the approach. From the top of the hill there is no odour, but nearer to the sheds – 100m long by 20m wide, with 42,000 chickens in each – the sweetish, sickly smell is overpowering. The broiler chickens, grown for meat, are stocked at around 17 birds per square metre. Birds are packed as far as the eye can see within the buildings, making it impossible to see the floor.



The chickens are trucked in as chicks, with just under a third “thinned” – removed from the sheds – to be slaughtered at just over four weeks old. The rest carry on to just over five weeks, when they weigh about 2.2kg. Eight crops of such chickens are reared each year, making 1.3m annually, with the sheds cleaned between every batch.

Quick Guide Megafarms Show What is a megafarm? There is no legal definition in the UK of a mega farm, but in the US concentrated animal feeding operations (CAFOs) are defined as those housing 125,000 broiler chickens, 82,000 laying hens, 2,500 pigs or 700 dairy or 1,000 beef cattle. These are the biggest of the intensive farms, which in the UK need permits if they house more than 40,000 chickens, 2,000 pigs or 750 breeding sows. There are now 789 mega farms in the UK, and the number of intensive farms has risen by more than a quarter in six years, from 1,332 in 2011 to 1,674 last year. Why are they controversial? Mega farms and intensive farms are controversial because they require keeping tens of thousands of animals in a small space, which campaigners and independent experts say can hamper their ability to express natural behaviours, such as nesting. The animals are often kept indoors throughout their lives, though on some farms they are allowed access to outdoor areas at least part of the time. There are also concerns that animals on mega farms may be over-medicated, as if one gets sick the whole herd is generally required to be treated. Why do some people believe we need them? Mega farms and intensive farms take up much less space than traditional farms, and they allow animals to be kept securely, away from predators and potential carriers of disease, such as badgers. Their conditions are tightly controlled, allowing farmers to monitor the amount of daylight, water and feed for the animals, and if disease develops the livestock can be treated quickly. They are much cheaper to run than traditional farms.

Richard Williams, the farmer, points to the enrichment that the birds enjoy: windows, so the animals have daylight and fresh air; straw bales they can jump on, with perches, and objects to peck; and the amount of light is carefully modified through the growing stages. “These things mean they can express their natural behaviours. Looking for the highest animal welfare is in my interest.” The conditions are in line with government regulations.

Each shed’s environment is carefully controlled so that the farmer can tell how much feed has been eaten, how much water consumed, the temperature, humidity and CO2 levels. Staff have a “poultry passport”, proving they are trained in how to look after the birds. A great deal of effort is spent in ensuring they are kept in optimum health: no antibiotic has been used since the site was set up two years ago, and the birds are given a product to improve their gut flora. “Like Yakult [for humans] it lets the good bacteria grow and stops the bad bacteria,” says Williams.

Inside the poultry house at Penrhos Poultry in Kington, England. Photograph: Rob Stothard

“Unless you’ve got a passion for this, and you care about their welfare, you don’t do it,” says Williams. “We’re in there Sunday mornings. If you chose to work with animals, you’ve got to care about them. It’s a weird concept because they’re going to die, but while they’re alive you care for them.”

The birds are fed on a mixture of pellets provided by Cargill, containing soya, minerals and other additives. This is mixed with wheat, mostly sourced locally. None of the material is genetically modified. The sheds are heated by biomass, from waste wood, reducing the carbon footprint. The farm supplies Cargill, which is one of the biggest employers in Herefordshire.

According to the UK government’s welfare guidance, broiler chickens raised for meat can be stocked at a density of 33kg or 39kg per square metre. As the average such chicken can weigh 2kg, that means about 15 or 20 birds in a square metre of space. The cages themselves are not a metre square, but larger, with room for the animals to move around. Free range chickens are allowed a square metre each. The sheds that Williams keeps chickens in do not have cages.

Complaints by local residents centre on issues such as smell, the potential for outbreaks of sewage pollution, and the noise and inconvenience of having industrial installations in a rural area.



Janet Srodzinski lives nearby – the four large broiler sheds were built 235m from her house, despite her objections and a judicial review. She can no longer enjoy her garden because of the smell, she says, from the ventilation chimneys. “It’s a horrible, sweet, sickly smell, a mix of bedding, chicken droppings, goodness only knows what. It’s weekends as well, 24/7. On Christmas Day 2015 I went out on to my terrace and was almost sick, the smell was dreadful all day. I pray for north winds now.”

There is also congestion from the lorries serving the farm, which often come at night and wake her, while the regular clear-outs bring the noise of power washers. “It’s a lovely county and these sheds have ruined it. For a tourist area, it’s just not very nice.”

She warned that other rural-dwellers will face similar experiences in future, as an increasing number of intensive farms are built or extended. “More people will have them erected near their houses. It’s going to be very difficult to stop it. In my opinion, if we’ve got to have chicken sheds, it’s got to be as far away from humans as possible.”

• This article was amended on 20 July 2017 to clarify that the sheds that Richard Williams keeps chickens in do not have cages.

Madlen Davies is science and health reporter at the Bureau of Investigative Journalism. Fiona Harvey is environment correspondent for the Guardian