Incubator - Furanki (English spelling) incubator

This is a device that holds bird eggs and incubates them artificially. Incubators that are commonly used are for chicken eggs. In China and Egypt, artificial incubation has been carried out using primitive incubators for over 2000 years. Today's improved incubators are available in flat and three-dimensional types, both of which create conditions similar to those experienced by a mother hen when she is incubating. Flat incubators are small and can hold around 100 to 500 eggs, while three-dimensional incubators can hold anywhere from 1,000 to tens of thousands of eggs. Both flat and three-dimensional incubators contain egg trays, a temperature regulator, a water basin to maintain humidity, and a hatching tray for hatching. Flat incubators have only one tray, but three-dimensional incubators have many trays on a shelf, and large incubators have separate incubation and hatching areas. Hatching eggs are lined up diagonally on the trays with the blunt end facing up. The optimum incubation temperature is 37 to 38 degrees Celsius. The three-dimensional type uses a fan or a frame-type air agitator to keep the temperature inside the chamber constant, but the flat type does not have this device and heats from above with radiant heat, so the temperature at the bottom is lower than at the top, so the temperature is about 1 degree C higher than that of the three-dimensional type. The humidity inside the chamber is not so strict, and the optimum relative humidity is kept in the range of 40 to 70% by using a water basin. Ventilation is good during incubation, and the oxygen concentration is kept at about 21%, the same as air, and carbon dioxide is kept below 1%. Eggs are also turned to prevent the chorion membrane of the embryo from adhering to the shell membrane and causing the embryo to die. In the flat type, this is done by hand 4 to 6 times a day, while in the three-dimensional type, the eggs are turned 8 to 10 times a day, either manually or automatically, by rotating each egg seat 40 to 45 degrees at a time. On the 18th day, they are transferred to a hatching seat and hatched on the 21st day.

[Nishida Tomoko]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

鳥類の卵を入れて人工的に孵化させる装置をいう。一般に利用されている孵卵器は鶏卵用のものである。中国やエジプトでは2000年以上も前から原始的な孵卵器で人工孵化を行っていた。現在の改良された孵卵器には平面式と立体式があり、どちらも母鶏の抱卵時と同様な条件をつくりだす。平面式は小形で100～500卵ほど入卵するもので、立体式は1000～数万卵まで収容できる。平面式、立体式ともに器内には、卵座、温度調整器、湿度を保つための水盤、孵化用発生座などがある。平面式は卵座は一段しかないが、立体式は棚状に多数の卵座があり、大形のものは孵卵区と発生区が別室になっている。種卵は卵座上に鈍端を上にして斜めに並べる。孵卵温度は37～38度Cが最適である。立体式は送風機または枠型の空気攪拌(かくはん)器で器内温度を一定に保つが、平面式はこの装置がなく上方から輻射(ふくしゃ)熱で加温するので下端のほうが上端より温度が低くなるため、立体式より約1度C高くする。器内の湿度はそれほど厳密でなく水盤によって最適相対湿度である40～70％の範囲に保たれる。孵卵中は換気をよくし、酸素濃度は空気と同じ21％ぐらい、二酸化炭素は1％以下に抑える。また卵殻膜に胚(はい)の絨毛(じゅうもう)膜が付着して胚が死亡するのを防ぐため転卵を行う。平面式では1日に4～6回手で行い、立体式では1日に8～10回卵座ごと手動または自動的に40～45度ずつ回転させて転卵させる。18日目に孵化用発生座に移して21日目に孵化させる。

［西田恂子］

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