CHICKEN English meaning

Skeletons of birds in the Gallus genus were used as grave goods at the site, confirming domestication. The chicks imprint on the hen and subsequently follow her continually. Eggs of chickens from the high-altitude region of Tibet have special physiological adaptations that result in a higher hatching rate in low oxygen environments. Hens often try to lay in nests that already contain eggs and sometimes move eggs from neighbouring nests into their own. As with all birds, reproduction is controlled by a neuroendocrine system, the Gonadotropin-Releasing Hormone-I neurons in the hypothalamus. Sperm transfer occurs by cloacal contact between the male and female, in an action called the ‘cloacal kiss’.

Genomic studies estimated that the chicken was domesticated 8,000 years ago in Southeast Asia and spread to China and India 2,000 to 3,000 years later. Fertile chicken eggs hatch at the end of the incubation period, about 21 days; the chick uses its egg tooth to break out of the shell. The concept of dominance, involving pecking, was described in female chickens by Thorleif Schjelderup-Ebbe in 1921 as the “pecking order”. https://eaub.info/login Individual chickens dominate others, establishing a pecking order; dominant individuals take priority for access to food and nest sites.

Domestication

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. Only hens that could no longer produce enough eggs were killed and sold for meat. Only in the early 20th century, however, did chicken meat and eggs become mass-production commodities.

• Hens of some breeds can produce over 300 eggs per year; the highest authenticated rate of egg-laying is 371 eggs in 364 days.
• The Sunday roast is often called the UK’s national dish, check out our roast dinner recipes for Sunday roasts that stand out at Jamie Oliver.
• While the origin is Germanic, it is unclear exactly where the word came from, although it could ultimately have come from an imitation of the sound a chicken makes.
• Females (mature hens and younger chickens, called pullets) are raised for meat and for their edible eggs.
• Sperm transfer occurs by cloacal contact between the male and female, in an action called the ‘cloacal kiss’.

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.

Reproduction and life-cycle

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. 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.

Mature males have long been used for sport (i.e., cockfighting, now outlawed in many jurisdictions) as well as for breeding. Farmers have developed numerous breeds and varieties to fulfill commercial requirements. Descendants of those domestications have spread throughout the world in several waves for at least the last 2,000 years. Chickens belonging to the same age cohort and sex are often kept together in industrial production settings. A flock usually includes one dominant adult male, a few subdominant males, and two or more females that are carefully watched over by the dominant male. Chicks are born covered in down, but they mature quickly, becoming fully feathered after four to five weeks.