Norfolk's countryside is now home to more so-called 'mega-farms' than anywhere else in the country thanks to a boom in intensive poultry production, we can reveal today.
The number of environmental permits for intensive livestock farming in Norfolk and Suffolk has gone up by around 75pc in the last two years from 131 to 231.
A total of 40 permits were given out in 2015 in the two counties and another 56 in 2016.
It has raised concerns about the impact on the environment of keeping tens of thousands of animals permanently indoors in one facility.
But the National Farmers' Union (NFU) said the UK had some of the highest environmental standards in the world and intensive farming could be good for the planet.
The permits are given out by the Environment Agency to sites with a capacity for at least 40,000 indoor or outdoor poultry birds, 700 indoor breeding pigs, or 2,500 indoor production pigs.
The highest number of intensive farms are in Breckland (53) and Mid Suffolk (52).
The largest facilities can hold more than 125,000 chickens for meat, 82,000 laying hens and 2,500 pigs, meaning they meet the US Environmental Protection Agency (EPA) definition for 'Large CAFO' (Concentrated Animal Feeding Operation) or 'mega farm'.
There is no equivalent definition in the UK, but analysis from The Bureau of Investigative Journalism (TBIJ) has found there are almost 800 of these 'mega-farms' in the UK, including 74 in Norfolk - more than any other county in the country.
In Suffolk, there are 44 and another six in Cambridgeshire, according to data obtained by TBIJ.
Around 40pc of all intensive livestock permits given in Norfolk and Suffolk since 2007 have gone to three poultry companies – Hook 2 Sisters, Bernard Matthews and Crown Chicken.
Hook 2 Sisters, half owned by food giant 2 Sisters, has permits for intensive poultry farming at 41 sites across Norfolk and Suffolk. It grows chickens mainly for supermarket own brand labels.
2 Sisters is owned by Boparan Holdings. And its owner Ranjit Singh Boparan bought Bernard Matthews in September 2016.
Bernard Matthews, which employs nearly 2,000 people across Norfolk and Suffolk, has 18 intensive permits for farms it operates.
Crown Chicken, meanwhile, has farms across South Norfolk and North Suffolk and has 25 permits.
Peter Melchett, policy director at the Soil Association which champions organic farming, said one reason for the growth in intensive poultry farming in the region was food firms liked to operate farms close to their processing plants.
2 Sisters has a large processing plant near Bungay, Bernard Matthews' home is Great Witchingham, while Crown Chicken is based at Weybread in North Suffolk.
Dr Melchett said there was a growth in mega farms across the industry driven by the financial pressure UK farming was under and market consolidation.
But despite the economic gains he warned of long-term disadvantages, including problems with animal waste disposal and disease spreading faster among poultry.
'If you want a resilient UK farming system, it really should be going for diversity,' he said.
Norfolk chairman of the Campaign to Protect Rural England (CPRE), Chris Dady, said they had many issues with intensive poultry units, including the greenhouse gas ammonia which is produced. He said people living near the units also raised concerns about dust and odour.
And he argued they should be viewed as industrial units rather than as farms. 'They are designed to produce very cheap meat,' he said. 'They are of industrial use but just happen to use a live product.'
But Brian Finnerty, from NFU East Anglia, said the environmental permit figures did not reflect the growth in free range farming which was also expanding.
He added: 'The UK's self-sufficiency in food has fallen from 75pc in 1991 to 61pc now so any growth in poultry is good news for the British public.
'In addition, new poultry units will have a lower environmental footprint than older sheds, using less heat and power, and often including renewable energy features such as biomass boilers and solar panels.
'British farmers produce high quality food to exacting welfare and environmental standards. The significant factor is not the size of the farm, or the system used, but the quality of management and stockmanship that particular farm operates to.'
The NFU said output of poultry meat was worth £659 million to the regional economy in 2015 and pig farming was worth £297 million.
Crown Chicken has not responded to a request for comment. Bernard Matthews and 2 Sisters declined to comment.
•Pigs thrive outdoors
The vast majority of intensive farming permits in Norfolk and Suffolk are for poultry, but around 20pc are for pigs.
These allow farmers to have 2,000 or more production pigs indoors or 700 or more breeding pigs.
They are held by individual farmers across the area rather than large food production firms and there has not been a rise in the number of intensive permits.
Rather, Alastair Butler, from Blythburgh Free Range Pork near Halesworth, said the region was ideal for outdoor pig farming.
'Pig farms in East Anglia are leading the way in higher welfare and less intensive systems,' he said.
He said the light sandy soil was ideal for outdoor pig farming.
'The pigs have a better life and there is a greater demand for this type of pork in this country and abroad,' he said.
'There are a lot of export opportunities. We are just about the only country in the world with this pig farming on this scale.'
•Who needs a permit?
The Environment Agency says farmers need to get a permit when they have a certain amount of animals as intensive farming can harm human health or the environment if not controlled.
Firms apply to the Agency for intensive poultry or pig production permits if the farm's capacity is at least 40,000 poultry birds (indoors and outdoors), 2,000 or more production pigs kept indoors or 700 or more breeding pigs also indoors.
The permits cover all aspects of farm management but not animal welfare.
They state the measures that must be used to control the most common risks of pollution.
They include managing ammonia release into the environment, which is emitted from animal manure and slurry, as well as smell and noise and air pollution.
Surface water and groundwater can also be polluted by intensive farm.
The permit makes sure that contaminated water is contained.
•What makes a 'mega farm'?
There is no definition for what makes a 'mega-farm' in the UK.
But by going through environmental permit data, TBIJ was able to find out which areas had the highest number of intensive livestock farms.
They then looked at the individual permits to see which farms would meet the official US Environmental Protection Agency (EPA) definition for 'Large CAFO' (Concentrated Animal Feeding Operation) or 'mega farm' of which there is no equivalent classification in the UK.
They would need to have the capacity for at least 125,000 broiler chickens, 82,000 laying hens, 2,500 pigs, 700 dairy cattle or 1,000 beef cattle. They found almost 800 in the UK.
But the NFU disputes the way 'mega-farms' has been calculated.
They say it is 'completely irrelevant' to use the US EPA definition which has different rules and regulations.
In the US 'mega-farms' have been blamed for pollution and deforestation.
•Do you have a story which needs investigating? Email tom.bristow@archant.co.uk or call 01603 772834
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