By Anna Hill
BBC Radio 4's Farming Today
The outbreak of bird flu on a turkey farm in Suffolk has sparked a debate over whether intensive farming or free-range is better for the animals.
Some argue that free-range birds are more at risk of disease
Intensive turkey farms often buy in one-day-old chicks, then raise the birds and, in some cases, slaughter and process them in factories on-site.
The turkeys are kept in sheds which are carefully monitored, and would contain about 7,000 birds in each, at about eight weeks old.
The bigger the birds get, the more space they are allowed.
The Bernard Matthews farm at Holton is a large operation, producing thousands of kilos of poultry meat each year.
The Holton site employs 1,000 staff, mainly in the processing plant, many of them are from other EU countries, including Hungary and Portugal.
Spread of disease
Bernard Matthews has interests in food companies around the world.
In the 1990s he acquired businesses in New Zealand, Germany, Hungary, the Czech Republic, Poland and Slovakia.
Large-scale farming such as this has been criticised by environmental groups.
With the current outbreak, farmers are concerned that their outdoor birds may be put under stress
They point out that any operation with so many birds is vulnerable, because disease entering the site can wipe out huge numbers of poultry very quickly.
They also question the safety of having internationally linked farms - if lorries are travelling between different countries then there is more possibility of animal diseases spreading.
On the other hand, those who run intensive poultry farms are keen to point out that they protect their livestock from disease coming in from outside, by keeping them in sealed sheds, with carefully monitored ventilation.
They are also in a better position, they say, than farmers with free-range birds, to monitor their health and administer medicine if necessary.
Free-ranging poultry are sometimes considered to be more at risk of getting bird flu, because the disease is known to be carried by wild birds, especially waterfowl.
Free-range birds are allowed out to run around, exposing them to potential disease.
With the current outbreak, farmers are concerned that their outdoor birds may be put under stress, when they have to be kept indoors, which could in itself make them more vulnerable to disease.
However, some farmers with free-range flocks are adamant that their poultry are healthier than intensively reared birds, and feel their exposure to the outdoors makes them stronger and less likely to succumb to disease.
In the UK there is a register for anyone owning flocks of more than 50 birds.
But the Trading Standards office in Suffolk, where the current outbreak is being handled, has told Farming Today they would prefer the register to cover all poultry, not just flocks of more than 50.