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"The best in the world" White Plymouth Rocks, 1910. In the United States, chickens were raised primarily on family farms or in some cases, in poultry colonies, such as Judge Emery's Poultry Colony [1] until about 1960. Originally, the primary value in poultry keeping was eggs, and meat was considered a byproduct of egg production. [2]
The Romans used them in divination, and the Egyptians made a breakthrough when they learned the difficult technique of artificial incubation. [27] Since then, the keeping of chickens has spread around the world for the production of food with the domestic fowl being a valuable source of both eggs and meat. [28]
Equally important, embryologists can carry out experiments on such embryos, close the egg again and study the effects later in development. 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. [101]
In the past, many chicken breeds were selected for both functions. However, since the advent of laying and meat hybrids, industrial chicken breeding has made a sharp distinction between chickens with either function, [43] so that certain characteristics have been promoted to an extreme degree. Partly due to the discussion about male offspring ...
Developments in shipping networks and technology have made long-distance distribution of agricultural produce feasible. Agricultural production across the world doubled four times between 1820 and 1975 (1820 to 1920; 1920 to 1950; 1950 to 1965; and 1965 to 1975) to feed a global population of one billion human beings in 1800 and 6.5 billion in ...
Subsistence farming is being superseded by intensive animal farming in the more developed parts of the world, where, for example, beef cattle are kept in high-density feedlots, and thousands of chickens may be raised in broiler houses or batteries. On poorer soil, such as in uplands, animals are often kept more extensively and may be allowed to ...
The Detroit Zoo in suburban Detroit said the birth Thursday was the first in its 96-year history. “Bandia had a very smooth pregnancy, which is so important for a first-time mom,” said Tami ...
Modern varieties of chicken such as the Cornish Cross, are bred specifically for meat production, with an emphasis placed on the ratio of feed to meat produced by the animal. The most common breeds of chicken consumed in the U.S. are Cornish and White Rock. [16] Chickens raised specifically for food are called broilers. In the U.S., broilers ...