Chicken Types, Characteristics & Uses

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.

Reproduction and life-cycle

By the mid-20th century, however, meat production had outstripped egg production as a specialized industry. For most of that period, chickens were a common part of the livestock complement of farms and ranches throughout Eurasia and Africa. 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.

• These chickens may have been introduced during pre-Columbian times to South America via Polynesian seafarers, but this is disputed.
• Budget, ethics and taste all come into the equation but what almost all chefs, cooks and food writers agree on is that a good-quality, free-range bird is vastly superior in flavour to a cheap factory-farmed bird.
• 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.
• Sperm transfer occurs by cloacal contact between the male and female, in an action called the ‘cloacal kiss’.
• For most of that period, chickens were a common part of the livestock complement of farms and ranches throughout Eurasia and Africa.
• 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.

The time between ovulation and egg-laying is approximately 23–26 hours. The chicken was the first bird species to have its genome sequenced. Large numbers of embryos can be provided commercially; fertilized eggs can easily be opened and used to observe the developing embryo.

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. These domesticated chickens spread across Southeast and South Asia where they interbred with local wild species of junglefowl, forming genetically and geographically distinct groups. It is estimated that chickens share between 71 and 79% of their genome with red junglefowl.

Roast chicken

It was first domesticated around 8,000 years ago and is one of the most common and widespread domesticated animals in the world.

Aged beef tacos with tarragon salsa and garlic crumb

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). While most p 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).