De Smit Lieve, Bruggeman Veerle, Tona Jacob K, Debonne Marianne, Onagbesan Okanlawon, Arckens Lut, De Baerdemaeker Josse, Decuypere Eddy
Laboratory of Physiology and Immunology of Domestic Animals, Katholieke Universiteit Leuven, Kasteelpark Arenberg 30, B-3001 Leuven, Belgium.
Comp Biochem Physiol A Mol Integr Physiol. 2006 Oct;145(2):166-75. doi: 10.1016/j.cbpa.2006.06.046. Epub 2006 Jul 26.
This study investigated the effect of non-ventilation of the incubator during the first 10 days of incubation on carbon dioxide (CO(2)) concentrations in the incubator and its effects on the embryonic and post-hatch development of the chicken (Gallus gallus). Two different incubation conditions were created, one incubator was kept at standard conditions, with adequate ventilation (V) and a second incubator was non-ventilated (NV) during the first ten days of incubation, allowing the CO(2) to rise. After the first 10 days, both incubations were continued under standard conditions. The experiment was repeated twice with different ages of the breeders (45 and 60 wks) which resulted in different CO(2) levels at ED10 (1.5 and 1%). The CO(2) concentration in the V incubators remained below 0.1% in these first 10 days. The eggs of the NV incubation showed higher pCO(2) levels in the air cell from ED10 until ED14 compared to the eggs of the V group. The NV embryos had significantly higher absolute and relative (to egg weight) body weights from ED10 until ED18, pointing to an accelerated embryonic growth. At internal pipping, the NV chick embryos had higher plasma corticosterone and T(3) levels and higher pCO(2) in the air cell. Chicks incubated under NV conditions hatched 10 h earlier in the first and 15 h earlier in the second experiment and the spread of hatch was narrower. During the post-hatch period, the NV chickens had a higher body weight compared to the V chickens. From these results, it is clear that higher levels of CO(2) during the first ten days of incubation have persistent (epigenetic) effects during the incubation and early post-hatch period.
本研究调查了孵化前10天孵化箱不通风对孵化箱内二氧化碳（CO₂）浓度的影响及其对鸡（家鸡）胚胎发育和出壳后发育的影响。创建了两种不同的孵化条件，一个孵化箱保持在标准条件下，通风良好（V），另一个孵化箱在孵化的前十天不通风（NV），使CO₂浓度上升。前十天后，两个孵化箱均在标准条件下继续孵化。使用不同年龄（45周和60周）的种鸡重复该实验两次，这导致孵化第10天（ED10）时CO₂水平不同（1.5%和1%）。在这前十天里，V组孵化箱中的CO₂浓度保持在0.1%以下。与V组的蛋相比，NV组孵化的蛋从ED10到ED14气室内的pCO₂水平更高。从ED10到ED18，NV组胚胎的绝对体重和相对体重（相对于蛋重）显著更高，表明胚胎生长加速。在内部啄壳时，NV组鸡胚胎的血浆皮质酮和T₃水平更高，气室内的pCO₂也更高。在第一个实验中，NV条件下孵化的雏鸡提前10小时出壳，在第二个实验中提前15小时出壳，且出壳时间分布更窄。在出壳后阶段，NV组鸡的体重高于V组鸡。从这些结果可以清楚地看出，孵化前十天较高水平的CO₂在孵化期间和出壳后早期具有持续的（表观遗传）影响。
