CHICKEN中文繁體翻譯：劍橋詞典

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. In older sources, and still often in trade and scientific contexts, chickens as a species are described as common fowl or domestic fowl.

Creamy white wine chicken

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 krikya-online.com 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.

• Certain breeds, such as silkies and many bantam varieties, are generally docile and are often recommended as good pets around children with disabilities.
• At about six months, males produce viable sperm, and females produce viable eggs.
• The pecking order is established within groups of female chicks by the 10th week of life.
• Chickens are capable of mobbing and killing a weak or inexperienced predator, such as a young fox.
• Modern egg-laying breeds rarely go broody and those that do often stop part-way through the incubation cycle.

In the wild, they scratch at the soil to search for seeds, insects, and animals as large as lizards, small snakes, and young mice. Some breeds have a mutation that causes extra feathering under the face, giving the appearance of a beard. Modern varieties however grow much faster; by day 35 a Ross 708 broiler may weigh 1.8 kg (4.0 lb) as against the 1.05 kg (2.3 lb) of a heritage chicken of the same age. Newly hatched chicks of both modern and heritage varieties weigh the same, about 37 g (1.3 oz).

What is a Chickens?

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. 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. Cockfighting is outlawed in many countries as involving cruelty to animals.

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. 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.

These chickens may have been introduced during pre-Columbian times to South America via Polynesian seafarers, but this is disputed. 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.

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 Some breeds, such as the Cochin, Cornish and Silkie, regularly go broody and make excellent mothers.

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. Chickens are descended primarily from the red junglefowl (Gallus gallus) and are scientifically classified as the same species. Under natural conditions, most birds lay only until a clutch is complete; they then incubate all the eggs.