Domestic turkey
The domestic turkey is a large fowl, one of the two species in the genus Meleagris and the same species as the wild turkey. Although turkey domestication was thought to have occurred in central Mesoamerica at least 2,000 years ago, recent research suggests a possible second domestication event in the area that is now the southwestern United States between 200 BC and 500 AD. However, all of the main domestic turkey varieties today descend from the turkey raised in central Mexico that was subsequently imported into Europe by the Spanish in the 16th century.
The domestic turkey is a popular form of poultry. It is raised throughout temperate parts of the world, partially because industrialized farming has made it very cheap for the amount of meat it produces. Female domestic turkeys are called hens, and the chicks are poults or turkeylings. In Canada and the United States, male turkeys are called toms. In the United Kingdom and Ireland, they are stags.
The great majority of domestic turkeys are bred to have white feathers because their pin feathers are less visible when the carcass is dressed, although brown or bronze-feathered varieties are also raised. The fleshy protuberance atop the beak is the snood and the one attached to the underside of the beak is known as a wattle.
The English-language name for this species results likely from an early misidentification of the bird with an unrelated species, guineafowl which was imported to England through the country of Turkey. The Latin species name means "chicken peacock".
History
The modern domestic turkey is descended from the South Mexican subspecies of wild turkey, found in Central Mexico in a region bounded by the present Mexican states of Jalisco to the northwest, Guerrero to the southwest, and Veracruz to the east. Ancient Mesoamericans domesticated this subspecies, using its meat and eggs as major sources of protein and employing its feathers extensively for decorative purposes. The Aztecs associated the turkey with their trickster god Tezcatlipoca, perhaps because of its perceived humorous behavior.Domestic turkeys were taken to Europe by the Spanish. Many distinct breeds were developed in Europe. In the early 20th century, many advances were made in the breeding of turkeys, resulting in breeds such as the Beltsville Small White.
The 16th-century English navigator William Strickland is generally credited with introducing the turkey into England. His family coat of arms – showing a turkey cock as the family crest – is among the earliest known European depictions of a turkey. English farmer Thomas Tusser notes the turkey being among farmer's fare at Christmas in 1573. The domestic turkey was sent from England to Jamestown, Virginia in 1608. A document written in 1584 lists supplies to be furnished to future colonies in the New World; "turkies, male and female".
Prior to the late 19th century, turkey was something of a luxury in the UK, with goose or beef a more common Christmas dinner among the working classes. In Charles Dickens' A Christmas Carol, Bob Cratchit had a goose before Scrooge bought him a turkey.
Turkey production in the UK was centered in East Anglia, using two breeds, the Norfolk Black and the Norfolk Bronze. These would be driven as flocks, after shoeing, down to markets in London from the 17th century onwards – the breeds having arrived in the early 16th century via Spain.
Intensive farming of turkeys from the late 1940s dramatically cut the price, making it more affordable for the working classes. With the availability of refrigeration, whole turkeys could be shipped frozen to distant markets. Later advances in disease control increased production even more. Advances in shipping, changing consumer preferences and the proliferation of commercial poultry plants has made fresh turkey inexpensive as well as readily available.
Recent genome analysis has provided researchers with the opportunity to determine the evolutionary history of domestic turkeys, and their relationship to other domestic fowl.
Behavior
Young domestic turkeys readily fly short distances, perch and roost. These behaviours become less frequent as the birds mature, but adults will readily climb on objects such as bales of straw. Young birds perform spontaneous, frivolous running which has all the appearance of play. Commercial turkeys show a wide diversity of behaviours including 'comfort' behaviours such as wing-flapping, feather ruffling, leg stretching and dust-bathing. Turkeys are highly social and become very distressed when isolated. Many of their behaviours are socially facilitated; i.e., expression of a behaviour by one animal increases the tendency for this behaviour to be performed by others. Adults can recognise 'strangers' and placing any alien turkey into an established group will almost certainly result in that individual being attacked, sometimes fatally. Turkeys are highly vocal, and 'social tension' within the group can be monitored by the birds' vocalisations. A high-pitched trill indicates the birds are becoming aggressive which can develop into intense sparring where opponents leap at each other with the large, sharp talons, and try to peck or grasp the head of each other. Aggression increases in frequency and severity as the birds mature.Maturing males spend a considerable proportion of their time sexually displaying. This is very similar to that of the wild turkey and involves fanning the tail feathers, drooping the wings and erecting all body feathers, including the 'beard'. The skin of the head, neck and caruncles becomes bright blue and red, and the snood elongates, the birds 'sneeze' at regular intervals, followed by a rapid vibration of their tail feathers. Throughout, the birds strut slowly about, with the neck arched backward, their breasts thrust forward and emitting their characteristic 'gobbling' call.
Size and weight
The domestic turkey is the eighth largest living bird species in terms of maximum mass at 39 kg. Due to their extreme size differences, domestic turkeys are semi-flightless, as younger or smaller specimens are still capable of short-distance flight, whereas the largest individuals are completely flightless and terrestrial.Turkey breeds
- The Broad Breasted White is the commercial turkey of choice for large scale industrial turkey farms, and consequently is the most consumed variety of the bird. Usually the turkey to receive a "presidential pardon", a U.S. custom, is a Broad Breasted White.
- The Broad Breasted Bronze is another commercially developed strain of table bird.
- The Standard Bronze looks much like the Broad Breasted Bronze, except that it is single breasted, and can naturally breed.
- The Bourbon Red turkey is a smaller, non-commercial breed with dark reddish feathers with white markings.
- Slate, or Blue Slate, turkeys are a very rare breed with gray-blue feathers.
- The Black has very dark plumage with a green sheen.
- The Narragansett Turkey is a popular heritage breed named after Narraganset Bay in New England.
- The Chocolate is a rarer heritage breed with markings similar to a Black Spanish, but light brown instead of black in color. Common in the Southern U.S. and France before the Civil War.
- The Beltsville Small White is a small heritage breed, whose development started in 1934. The breed was introduced in 1941 and was admitted to the APA Standard in 1951. Although slightly bigger and broader than the Midget White, both are often mislabeled.
- The Midget White is a smaller heritage breed.
Commercial production
In the UK, it is common to rear chicks in the following way. Between one and seven days of age, chicks are placed into small circular brooding pens to ensure they encounter food and water. To encourage feeding, they may be kept under constant light for the first 48 hours. To assist thermoregulation, air temperature is maintained at for the first three days, then lowered by approximately 3 °C every two days to at 37 days of age, and infrared heaters are usually provided for the first few days. Whilst in the pens, feed is made widely accessible by scattering it on sheets of paper in addition to being available in feeders. After several days, the pens are removed, allowing the birds access to the entire rearing shed, which may contain tens of thousands of birds. The birds remain there for several weeks, after which they are transported to another unit.
The vast majority of turkeys are reared indoors in purpose-built or modified buildings of which there are many types. Some types have slatted walls to allow ventilation, but many have solid walls and no windows to allow artificial lighting manipulations to optimise production. The buildings can be very large and may contain tens of thousands of birds as a single flock. The floor substrate is usually deep-litter, e.g. wood shavings, which relies upon the controlled build-up of a microbial flora requiring skilful management. Ambient temperatures for adult domestic turkeys are usually maintained between. High temperatures should be avoided because the high metabolic rate of turkeys makes them susceptible to heat stress, exacerbated by high stocking densities. Commercial turkeys are kept under a variety of lighting schedules, e.g. continuous light, long photoperiods, or intermittent lighting, to encourage feeding and accelerate growth. Light intensity is usually low to reduce feather pecking.
Rations generally include corn and soybean meal, with added vitamins and minerals, and is adjusted for protein, carbohydrate and fat based on the age and nutrient requirements. Hens are slaughtered at about 14–16 weeks and toms at about 18–20 weeks of age when they can weigh over compared to a mature male wild turkey which weighs approximately.