Chicken Wikipedia231800
Chicken recipes
Newly hatched chicks of both modern and heritage varieties weigh the same, about 37 g (1.3 oz). 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. The word chicken comes from Old English cicen (pronounced essentially the same as in Modern English).
Africa
- 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.
- In some other countries, flocks are sometimes force-moulted rather than being slaughtered to re-invigorate egg-laying.
- Chickens are social, inquisitive, intelligent birds, and many people find their behaviour entertaining.
- For most of that period, chickens were a common part of the livestock complement of farms and ranches throughout Eurasia and Africa.
- The time between ovulation and egg-laying is approximately 23–26 hours.
- As of 2023, the global chicken population exceeds 26.5 billion, with more than 50 billion birds produced annually for consumption.
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. Under natural conditions, most birds lay only until a clutch is complete; they then incubate all the eggs.
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.
Domestication and economic production
Phoenicians spread chickens along the Mediterranean coasts as far as Iberia. These chickens may have been introduced during pre-Columbian times to South America via Polynesian seafarers, but this is disputed. Skeletons of birds in the Gallus genus were used as grave goods at the site, confirming domestication.
Chickens are primarily kept for their meat and eggs, though they are also kept as pets. 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. In groups of male chicks, however, fights for dominance may continue into adulthood. The pecking order is established within groups of female chicks by the 10th week of life. The time between ovulation and egg-laying is approximately 23–26 hours. In 2006, scientists researching the ancestry of birds switched on a chicken recessive gene, talpid2, and found that the embryo jaws initiated formation of teeth, like those found in ancient bird fossils.
Farming
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; khelaghor-bangladesh.com/bd/ 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”. Individual chickens dominate others, establishing a pecking order; dominant individuals take priority for access to food and nest sites.
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.
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