Chicken Types, Characteristics & Uses

There are over 150 different breeds of chicken that come in various colors, patterns and sizes. The market for chicken meat has grown dramatically since then, with worldwide exports reaching nearly 12.5 million metric tons (about 13.8 million tons) by the early 21st century. By the mid-20th century, however, meat production had outstripped egg production as a specialized industry.

• Descendants of those domestications have spread throughout the world in several waves for at least the last 2,000 years.
• The chicken (Gallus gallus domesticus) is a domesticated form of the red junglefowl (Gallus gallus), originally native to Southeast Asia.
• Chicken wattles differ in size since some chickens have bigger wattles than others.
• A broody hen will sit fast on her nest and will protest if disturbed or removed.

After 12 months of laying, the commercial hen’s egg-laying ability declines to the point where the flock is commercially unviable. 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 https://khelovipbangladesh.com hatch at the end of the incubation period, about 21 days; the chick uses its egg tooth to break out of the shell. Individual chickens dominate others, establishing a pecking order; dominant individuals take priority for access to food and nest sites.

Flightless Birds

An adult male bird is a cockerel or rooster, while a female adult chicken is called a hen. Besides humans, lots of animals eat chickens as well. The life span of a chicken varies between 5 – 7 years although there have been cases of chickens living 20 years or so.

Chicken’s Anatomy External Part

Exactly when and where the chicken was domesticated was controversial. 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.

Farming

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. Equally important, embryologists can carry out experiments on such embryos, close the egg again and study the effects later in development. Chickens are social, inquisitive, intelligent birds, and many people find their behaviour entertaining. This involves complete withdrawal of food (and sometimes water) for 7–14 days or sufficiently long to cause a body weight loss of 25 to 35%, or up to 28 days under experimental conditions.