Chicken Wikipedia
Advocates of intensive farming say that their efficient systems save land and food resources owing to increased productivity, and that the animals are looked after in a controlled environment. Chickens are common and widespread domestic animals, with a total population of 23.7 billion as of 2018update. Breeding increased under the Roman Empire and reduced in the Middle Ages. Middle Eastern chicken remains go back to a little earlier than 2000 BC in Syria. Chickens reached Egypt via the Middle East for purposes of cockfighting about 1400 BC and became widely bred in Egypt around 300 BC.
Chicken recipes
- Some breeds have a mutation that causes extra feathering under the face, giving the appearance of a beard.
- The dance triggers a response in the hen and when she responds to his call, the rooster may mount the hen and proceed with the mating.
- Skeletons of birds in the Gallus genus were used as grave goods at the site, confirming domestication.
- If the female is unreceptive, she runs off; otherwise, she crouches, and the male mounts, treading with both feet on her back.
- Hens often try to lay in nests that already contain eggs and sometimes move eggs from neighbouring nests into their own.
- The concept of dominance, involving pecking, was described in female chickens by Thorleif Schjelderup-Ebbe in 1921 as the “pecking order”.
The possibility that domestic chickens were in the Americas before Western contact is debated by researchers, but blue-egged chickens, found only in the Americas and Asia, suggest an Asian origin for early American chickens. Analysis of the most popular commercial breed shows that the White Leghorn breed possesses a mosaic of divergent ancestries inherited from different subspecies of red junglefowl. Archaeological evidence appeared to support domestic chickens in Southeast Asia well before 6000 BC, China by 6000 BC and India by 2000 BC. Exactly when and where the chicken was domesticated was controversial. Inbreeding of White Leghorn chickens tends to cause inbreeding depression expressed as reduced egg number and delayed sexual maturity. When eggs are placed in a hypoxic environment, chicken embryos from these populations express much more hemoglobin than embryos from other chicken populations.
Chicken recipes
To initiate courting, some roosters may dance in a circle around or near a hen (a circle dance), often lowering the wing which is closest to the hen. Chickens give different warning calls to indicate that a predator is approaching from the air or on the ground. A male’s crowing is a loud and sometimes shrill call, serving as a territorial signal to other males, and in response to sudden disturbances within their surroundings. Chickens are capable of mobbing and killing a weak or inexperienced predator, such as a young fox. Some breeds have a mutation that causes extra feathering under the face, giving the appearance of a beard.
Chicken domestication likely occurred more than once in Southeast Asia and possibly India over the most recent 7,400 years, and the first domestications may have been for religious reasons or for the raising of fighting birds. Each flock of chickens develops a social hierarchy that determines access to food, nesting sites, mates, and other resources. At about six months, males produce viable sperm, and females produce viable eggs. Despite the chicken’s close relationship with the red jungle fowl, there is evidence that the gray jungle fowl (G. sonneratii) of southern India and other jungle fowl species, also members of Gallus, may have contributed to the bird’s ancestry. The chicken is a sacred animal in many cultures and deeply embedded in belief systems and religious practices.Roosters are sometimes used for divination, a practice called alectryomancy. This stimulates the hen to lose her feathers but also re-invigorates egg-production.
A cockfight is a contest held in a ring called a cockpit between two cocks. Certain breeds, such as silkies and many bantam varieties, are generally docile and are often recommended as good pets around children with disabilities. Chickens are social, inquisitive, intelligent birds, and many people find their behaviour entertaining. This involves complete withdrawal of food (and sometimes water) for 7–14 days or sufficiently long to cause a body weight loss of 25 to 35%, or up to 28 days under experimental conditions. Hens, particularly from battery cage systems, are sometimes infirm or have lost a significant amount of their feathers, and their life expectancy has been reduced from around seven years to less than two years. Broiler breeds typically take less than six weeks to reach slaughter size, some weeks longer for free-range and organic broilers.
The pseudo-riddle “Why did the chicken cross the road?” dates to 1847, or earlier. This involves the sacrifice of a sacred rooster, often during a ritual cockfight, used as a form of communication with the gods. Chickens are featured widely in folklore, religion, literature, and popular culture. The chicken was the first bird species to have its genome sequenced. For instance, many important discoveries in limb development have been made using chicken embryos, such as the discovery of the apical ectodermal ridge and the zone of polarizing activity. Equally important, embryologists can carry out experiments on such embryos, close the egg again and study the effects later in development.
Egg laying is stimulated by the long stretches of daylight that occur during the warmer months; however, artificial lights placed in chicken coops can trigger a hen’s egg laying response throughout the year. Males (called cocks or roosters) and females (hens) are known for their fleshy combs, lobed wattles hanging below the bill, and high-arched tails. In the process of domestication, chickens were apparently kept initially for cockfighting, and only later used for food. Many people obtain chickens for their egg production but often name them and treat them as any other pet like cats or dogs. Genetic sequencing of chicken bones from archaeological sites in Europe revealed that in the High Middle Ages chickens became less aggressive and began to lay eggs earlier in the breeding season.
Under natural conditions, most birds lay only until a clutch is complete; they then incubate all the eggs. Adult chickens of both sexes have a fleshy crest on their heads called a comb or cockscomb, and hanging flaps of skin on either side under their beaks called wattles; combs and wattles are more prominent in males. In older sources, and still often in trade and scientific contexts, chickens as a species are described as common fowl or domestic fowl.
Re-examination of bones from over 600 sites, and dating of those from 23 sites, identified the earliest probable chicken bones as from central Thailand, at Ban Non Wat, some 3,250 years ago. Hens remain on the nest for about two days after the first chick hatches; during this time the newly hatched khela 88 chicks feed by absorbing the internal yolk sac. The hen sits on the nest, fluffing up or pecking defensively if disturbed.