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The American Pekin duck, Pekin duck, or Long Island duck (''Anas platyrhynchos domestica'', or ''Anas peking''〔), is a breed of domestic duck used primarily for egg and meat production. It was bred from the mallard in China. The ancestors of those ducks originated from the canals which linked waterways in Nanjing and originally had small bodies and black feathers. With the relocation of the Chinese capital to Beijing, supply barge traffic increased in the area which would often spill grain on which the ducks fed. Over time, the ducks slowly increased in size and grew white feathers. By the Five Dynasties, the new breed of duck had been domesticated by Chinese farmers. The Pekin duck is the most popular commercial duck breed in the United States, after a small number were imported to Long Island from China in 1873 by James Palmer of Stonington, Connecticut. The animals and their meat are sometimes referred to as "Long Island duckling". Around 95% of duck meat consumed in the United States is Pekin duck. ==Hatching== Pekin duck embryos take around 28 days to develop in the egg at 99.5°F (37.5°C) and 50-75% humidity. A heartbeat can usually be seen by the third day of incubation when candling the egg. The eggs must be regularly turned during incubation. This occurs in nature when the female duck shifts her position while sitting on the eggs. For artificial incubation, machines are available which will constantly turn the eggs. When being artificially incubated, the eggs are moved to a "hatcher" three days before they are due to hatch. This has a slightly lower temperature and higher humidity which increases the survivability of the hatchlings while their protective down develops. Compared with other birds, duck eggs are relatively easy to hatch, as they are very forgiving of variations in temperature and humidity. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「American Pekin duck」の詳細全文を読む スポンサード リンク
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