Chicken Wikipedia
This stimulates the hen to lose her feathers but also re-invigorates egg-production. In some other countries, flocks are sometimes force-moulted rather than being slaughtered to re-invigorate egg-laying. After 12 months of laying, the commercial hen’s egg-laying ability declines to the point where the flock is commercially unviable. According to the Worldwatch Institute, 74% of the world’s poultry meat and 68% of eggs are produced this way. 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. 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.
- For most of that period, chickens were a common part of the livestock complement of farms and ranches throughout Eurasia and Africa.
- The pseudo-riddle “Why did the chicken cross the road?” dates to 1847, or earlier.
- Newly hatched chicks of both modern and heritage varieties weigh the same, about 37 g (1.3 oz).
- An early study proposed that a single domestication event of the red junglefowl in present-day Thailand gave rise to the modern chicken.
Social hierarchy
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. Domesticated chickens freely interbreed with populations of red junglefowl.
Cockfighting
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. Large numbers of embryos can be provided commercially; fertilized eggs can https://khelaghor-bangladesh.com/ easily be opened and used to observe the developing embryo. Keeping chickens as pets became increasingly popular in the 2000s among urban and suburban residents. The first pictures of chickens in Europe are found on Corinthian pottery of the 7th century BC. Phoenicians spread chickens along the Mediterranean coasts as far as Iberia.
Add chicken to one of your lists below, or create a new one. To add chicken to a word list please sign up or log in. Mature males have long been used for sport (i.e., cockfighting, now outlawed in many jurisdictions) as well as for breeding.
Domestication
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.
