More than 22 million turkeys are produced for meat in the UK each year. Most are reared intensively on farms like that pictured below, operated by the Bernard Matthews company at Holton, Suffolk, which suffered a birdflu outbreak in February 2007.
Day-old chicks or poults supplied by hatcheries are transferred to the windowless rearing sheds, where they will spend their lives. Some smaller units use pole barns, where the top half of the wall is made of fencing to allow in extra light and air, but keep out wild birds.
A litter of wood shavings and straw, which covers the floor to absorb spilled water and faeces, will not be changed during their lives, but may be added to or dried out if necessary.
Lighting is kept dim - in some cases four times lower than a street lamp - which is said to avoid aggression. Some birds are debeaked to stop them pecking each other.
The birds are fed cereals, vitamins and amino acids. In Britain, no meat and bone meal from poultry, cattle or any other animal is fed to poultry. Fishmeal is sometimes added. The British poultry industry is the biggest user of British wheat, consuming almost one fifth of the total annual UK wheat crop.
Intensively reared birds are bred for fast weight gain, which can cause health problems. The British Poultry Council says turkeys are reared to 13kg at around 20 weeks. The RSPCA says that depending on breeds, a modern male turkey may reach up to 25kg at 20 weeks.
The poults are fenced in around brooder units with heat lamps when young to keep them warm. As they grow, they roam about the shed, eating and drinking on demand from automated feeders.
Towards the end of their lives, as their weight and size increases , numbers will be "thinned" to allow more space.
The Bernard Matthews site at Holton has 22 rearing sheds on the old runways of the former Halesworth airfield. The 500m-long sheds start with about 7,000 birds in each.
Stocking density can vary according to the age and weight of the birds.
Industry and government standards use a formula based on the weight of the birds. They recommend a minimum floor area per bird, in enclosed housing, of 0.026 square metres per kilogram - a maximum stocking density of 40kg per square metre. The RSPCA Freedom Food scheme turkeys, for example, are stocked up to a maximum of 25kg per sq m.
The birds are checked by stockmen two to three times a day. If birds are found to be injured they can be isolated or put down depending on the seriousness of the injury.
Biosecurity measures are taken to control anything entering the sheds - including staff, feed and litter. Staff must wear protective clothing that is adaptable to biosecurity measures and cleaning. This is usually a process of scrubbing with disinfectant and foot dips on entering and leaving each shed, and between different sheds.
The feed is heat-treated and stored in secure bins and checked and change between flocks. The litter is also removed and the sheds are cleaned and tested for pathogens such as salmonella and E-coli after the turkeys are removed for slaughter.
Turkeys can live up to 10 years in the wild. Indoor-farmed turkeys are usually slaughtered between 12 and 21 weeks. Many free-range operations insist on a minimum of about 20 weeks.
Teams of "catchers" are used to collect the birds from the sheds for slaughter. The birds are put into crates for transfer to the abattoir - which may be on the same site.
If not, the crates - or modules - are loaded onto lorries. Each module has a roof and there must be side curtains on the lorry to protect them from the elements. Out of the 850 million birds transported each year, the mortality rate is less than 0.19%, according to the British Poultry Council. Lorries must be sprayed down after each operation.
The birds are inspected by a government vet before being killed.
The birds are taken from crates and hung upside down in shackles on a moving chain. Some plants dip the birds into an electric bath to stun them before they are killed. Other premises, such as the Bernard Matthews site at Holton, use gas to stun them first.
The carcasses are dipped into a scald tank of hot water to help loosen the feathers. Then they move to mechanical plucking machines, where revolving rubber fingers remove the feathers.
The birds are hung on shackles to be stunned, killed and plucked (photo: British Poultry Council)
The British Poultry Council says the carcass and intestines of each bird are examined to check for signs of disease. Suspicious carcasses are rejected.
The carcasses are then washed using clean water and chilled down to 4C by cold air jets or cold water sprays.
The birds are left for a period to ensure the meat is tender before being automatically weighed and sorted. Some may be packed as whole oven birds or go on to be cut into portions.
Factory A: At the Bernard Matthews farm in Holton, the dead birds are butchered here. The meat is filleted and choice cuts are packaged.
Factory B: Further processing of the meat occurs here to make products such as turkey burgers and breaded escalopes.
Turkey meat is processed into a selection of products
Companies can legally add up to 5% water to any food without declaring it as an ingredient.
If they add more than that - or over 10% for bacon or gammon - it must be stated on the label.
Finished products are kept frozen at the cold store before distribution.