鶏の孵化率に及ぼす貯卵の影響-1-室温保存の影響

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White Leghorn種雌にNew Hampshire種雄を配して得た種卵を, 室温に1-8日間保存して, 孵化率に及ぼす保存の影響を検討した.実験期間I (4月19-26日に産卵したもの), II (5月10-17日), III (5月31-6月7日), IV (6月21-28日), V (7月12-19日), VI (8月2-9日), VII (8月23-30日), VI (9月13-20日)の計8回, 6274卵についての結果は次の通りであつた.1.産卵率は平均67.33% (60.91-74%), 産卵数に対する種卵合格率は平均82.35%(79.09-87.01)であつた.2.実験期間I-VIIIにおける, 種卵の受精率は92.63, 90.26, 87.38, 86.90, 85.81, 86.71, 83.75, 75.99%であり, 受精卵に対する孵化率は92.16, 91.65, 89.30, 88.90, 82.85, 83.31, 80.24, 84.65%で, これらの平均は87.36%であつた.3.室温に1-8日間保存した場合の孵化率は, 受精卵に対し92.43, 89.42, 89.85, 88.49, 87.16, 86.43, 85.94, 79.14%で, 僅かながら漸次低下する傾向がみられた.また, 入卵後22日で孵化した雛は, 保存1日の2.07%から保存8日の5.80%へ増大し, 保存日数が長くなるにつれて孵化日数も遅延する傾向が認められた.4.さらに保存日数と孵化率の関係を, 実験期間別にみると, I-IVにおいては, 7-8日保存を行なつても殆んど孵化率の低下はみられないが, V-VIIIにおいては, 5日間以上の保存の場合に, 急激な孵化率の低下がみられる.その原因は, 概略27℃以上の高温の持続によつて, 胚が不完全な発生を開始するためであろうと推察されるが, 正確なことはさらに検討を要する.

The effect of holding eggs before incubation on the hatchability of the eggs was examined by using eggs laid by hybrids between New Hampshire males and White Leghorn females. A total 6, 274 hatching eggs were incubated after held at room temperature for 1 to 8 days. Experiments were carried out in the following eight period : I, eggs laid during a period of April 19 to 26; II, May 10 to 17; III, May 31 to June 7; IV, June 21 to 28; V, July 12 to 19; VI, August 2 to 9; VII, August 23 to 30; and VIII, September 13 to 20. The results obtained were summarized as fallows. 1) The average percentages of eggs laid and hatching eggs were 67.33% (range: 60.91-74.00%) and 82.35% (range: 79.09-87.01%), respectively. 2) In experimental periods I to VIII, the fertility rate of hatching eggs was 92.63, 90.26, 87.38, 86.90, 85.81, 86.71, 83.75, and 75.99-0x1.fb11p+0nd the hatchability of fertile eggs was 92.16, 91.65, 89.30, 88.90, 82.85, 83.31, 80.24, and 84.65%, respectively. The latter averaged 87.36%.0 3) When eggs were held at room temperature for 1, 2, 3, 4, 5, 6, 7, and 8 days, the hatchability of fertile eggs wss 92.43, 89.42, 89.85, 88.49, 87.16, 86.43, 85.94, and 79.14%, respectively. The percentage of chicks hatched at 22 days of incubation ranged from 2.0726662615000f eggs held for one day to 5.8026662621600f those held for 8 days. 4) When the eight experimental periods were compared, an especially low hatchability was shown among the eggs held for 5 days or more in July and August (experimental periods V to VII). From these results, it is suggested that the low hatchability may have been brought about by the continuation of such high temperature as approximately 27℃. Futher studies are need, however, before any conclusion is made on this subject.

source:The technical bulletin of Faculty of Horticulture, Chiba University