Britain urged to ape countries such as the US and Saudi Arabia and build farms housing tens of thousands of cows or pigs

The president of the National Farmers Union believes the UK needs more and bigger "super farms" to keep food prices from rising too high and to maintain high animal welfare standards.

Peter Kendall gave his views as figures reportedly showed that the lack of farmland in Britain was now as acute as the shortfall in China.

Proposals for the first livestock farms that would breed thousands of animals have been dubbed mega farms by critics who claim they will create mass herds in sterile conditions where injuries will go unnoticed, disease will spread quickly and the environment will struggle to cope with the slurry and pollution.

But, as planning experts continue to consider at least two planning applications for large-scale pig and dairy farms, Kendall said that more super farms would be created and the government should make adjustments to allow some farms to keep several thousand animals and be part of a trial aimed at helping Britain feed its population as food demand rises around the world.

The problem thought to be facing Britain is highlighted by figures from the Agriculture and Horticulture Development Board showing that, though Britain has about 5% of China's 1.3 billion population, it has less than 3% of its land area.

An independent report by the Parliamentary Office of Science and Technology (Post) found that much larger farms than those in Britain could be "both good and bad" for animal welfare and the environment, arguing that they could "potentially" improve conditions for animals and the protection of the environment.

"The challenge of feeding everybody with the constraints of climate change and weather shocks is so great we'll need a complete rethink," said Kendall.

Although livestock farms in the UK have been consolidating for many years, Post's report, entitled Livestock Super Farms, found that typically the units held 100 to 150 head of cattle or pigs.

Even the biggest UK farms are dwarfed by the mega farms of other countries. In the US, farms with 10,000 pigs are not uncommon and Saudi Arabia has a super dairy with a herd of 37,000.

In Britain last year, there was a move to house 8,000 dairy cows at Nocton, Lincolnshire. This application from Nocton Dairies was withdrawn because of official concerns about water pollution and the animal welfare protest that took place at Westminster in 2010.

Two more scaled-up proposals are being considered. These are a farm for 2,500 sows and their piglets at Foston, Derbyshire, and another for 1,000 cows in Powys, Wales.

Last year, too, a government report on the future of food and farming stated that "the global food supply must be increased through sustainable intensification" to cope with population increase, climate change and other factors. Ministers are now waiting to hear from a working group on the subject.

Post records large farms in the UK, but perhaps because they have grown piecemeal, or been split between various land holdings, they have not attracted any high-profile attention from animal rights and environment campaigners.

Concerns about large-scale animal farming fall into four categories: of animal welfare; of super units destroying small farms and rural communities; of farms straining soil and water resources and requiring mass transport of chemicals, generating more greenhouse gas pollution; and of such units being unsightly and emitting foul smells.

Kendall said the UK was about 62% self-sufficient in the food it could produce overall and 40% self-sufficient with regard to pork – so there was "plenty of scope" for big producers while still leaving room for smaller ones.

At the heart of Kendall's defence of super farms is his belief that bigger farms are more profitable (or less loss-making) so can afford better equipment, more space and experts able "to protect the environment and animals".

He highlighted the Foston application, from Midland Pig Producers, which proposed building an abattoir near the farm so the pigs would not have to travel far to slaughter.

The plan was also to fit equipment to trap ammonia and other gasses to protect local residents and to generate "renewable" electricity and heat. The applicants had promised to achieve the RSPCA's Freedom Food accreditation for animal welfare.

Kendall argued that farmers running large units would generally be able to afford to employ veterinarians and other experts such as nutritionists, and to attract other operations to local areas, such as ethanol plants generating high-quality protein waste that could be used as feed.

"I want to make sure we're not importing food that's produced to lower welfare standards and therefore driving our farmers out."

He envisaged more farms on the scale of Foston or the Powys proposal. Much bigger operations, similar to the withdrawn Nocton scheme, could be tried out, he said, though he did not think that would become the norm, principally because it was hard to find locations far enough away from population centres.

"This is about a few experimental versions, so we can see whether it lowers greenhouse gas emissions, see whether it's welfare friendly, see what the impacts are on the environment."

Compassion in World Farming (CWF) said it was deeply uncomfortable about mega farms, particularly since they usually relied on animals being kept indoors.

Joyce D'Silva, CWF's director of public affairs, said there was "good scientific evidence" showing it was better for farm animals to go outside, and that it was harder for workers to pick out lame or ill animals kept in the thousands.

"We see each animal as an individual sentient being," D'Silva said. "The market would put animals in thousands: it's hard to treat them as individuals."

Farming in numbers



110: average dairy herd in the UK

8,000: cows in original application for Nocton super dairy

37,000: size of herd at a mega dairy farm in Saudi Arabia

148: average number of sows on a UK pig farm

2,500: pigs that would be housed in new farm at Foston

10,000: pigs at a US mega farm

Source: Post, March 2012