CHICKEN中文繁體翻譯：劍橋詞典

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. Subsequent ovulations may occur within an hour after the previous egg was laid, allowing some hens to produce as many as 300 eggs per year. 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.

• In situations where one adult bird challenges another—which happens most often when a new bird is introduced into the flock—fights involving males risk injury and death more often than fights involving females.
• The parasite Dermanyssus gallinae feeds on blood, causing irritation and reducing egg production, and acts as a vector for bacterial diseases such as salmonellosis and spirochaetosis.Viral diseases include avian influenza.
• Roosters can usually be differentiated from hens by their striking plumage, marked by long flowing tails and bright pointed feathers on their necks.
• Many immature males (cockerels) are castrated (usually chemically, with hormones that cause atrophying of the testicles) to become meat birds (capons).
• Sometimes a hen will stop laying eggs to concentrate on the incubation of her eggs.
• Opponents of intensive farming argue that it harms the environment, creates human health risks and is inhumane towards sentient animals.

Hens remain on the nest for about two days after the first chick hatches; during this time the newly hatched chicks feed by absorbing the internal yolk sac. The hen sits on the nest, fluffing up or pecking defensively if disturbed. Reproduction declines with age, thought to be due to a decline in GnRH-I-N. 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. 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.

Social hierarchy

In domesticating the chicken, humans took advantage of the red junglefowl’s ability to reproduce prolifically when exposed to a surge in its food supply. The chicken (Gallus gallus domesticus) is a domesticated form of the red junglefowl (Gallus gallus), originally native to Southeast Asia. Females (mature hens and younger chickens, called pullets) are raised for meat and for their edible eggs. The chicken is perhaps the most widely domesticated fowl, raised worldwide for its meat and eggs.

These domesticated chickens spread across Southeast and South Asia where they interbred with local wild species of junglefowl, forming genetically and geographically distinct groups. Specialized breeds such as broilers and laying hens have been developed for meat and egg production, respectively. In the United States alone, more than 8 billion chickens are slaughtered each year for meat, and more than 300 million chickens are reared for egg production. More than 50 billion chickens are reared annually as a source of meat and eggs. An early study proposed that a single domestication event of the red junglefowl in present-day Thailand gave rise to the modern chicken. It is estimated that chickens share between 71 and 79% of their genome with red junglefowl.

Chicken traybake with chorizo, tomato and red peppers

Hens of some breeds can produce over 300 eggs per year; the highest authenticated rate of egg-laying is 371 eggs in 364 days. During the Hellenistic period (4th–2nd centuries BC), in the southern Levant, chickens began to be widely domesticated for food. The red junglefowl is well adapted to take advantage of the vast quantities of seed produced during the end of the multi-decade bamboo seeding cycle, to boost its own reproduction. most-play-bangladesh.com Chickens are descended primarily from the red junglefowl (Gallus gallus) and are scientifically classified as the same species.

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.

Sometimes a hen will stop laying eggs to concentrate on the incubation of her eggs. When a rooster finds food he may call the other chickens to eat it first. Although chickens are flightless birds, they do have a tendency to attempt flight.

The concept of dominance, involving pecking, was described in female chickens by Thorleif Schjelderup-Ebbe in 1921 as the “pecking order”. Chickens are gregarious, living in flocks, and incubate eggs and raise young communally. 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. The body is round, the legs are unfeathered in most breeds, and the wings are short. Chicken can mean a chick, and this was historically the meaning of the word chicken, as in William Shakespeare’s play Macbeth, where Macduff laments the death of “all my pretty chickens and their dam”. Check out more animals that begin with the letter C

The word chicken comes from Old English cicen (pronounced essentially the same as in Modern English). Chickens are social animals with complex vocalizations and behaviors, and feature in folklore, religion, and literature across many societies.

The domestic chicken has subsequently hybridised with grey junglefowl, Sri Lankan junglefowl and green junglefowl; a gene for yellow skin, for instance, was incorporated into domestic birds from the grey junglefowl (G. sonneratii). Domesticated chickens freely interbreed with populations of red junglefowl. Strongly inbred Langshan chickens display obvious inbreeding depression in reproduction, particularly for traits such as age when the first egg is laid and egg number.