Agbehadzi R K, Kumi G, Adjei-Mensah B, Hamidu J A, Tona K
Laboratory of Regional Center of Excellence for Poultry Science, University of Lomé, 01 BP 1515, Lomé, Togo.
Laboratory of Regional Center of Excellence for Poultry Science, University of Lomé, 01 BP 1515, Lomé, Togo.
Poult Sci. 2025 Feb;104(2):104691. doi: 10.1016/j.psj.2024.104691. Epub 2024 Dec 24.
The present study examined the effects of breeder age and oxygen (O₂) concentrations during the late chorioallantoic membrane (CAM) growth stage on embryo development, hatching dynamics, chick quality, bone mineralization and hatchability. A total of 1200 eggs from 33- and 50-week-old ISA layer breeders, weighing 53.85 g and 60.42 g on average respectively, were incubated at 37.7°C and 56 % relative humidity. From embryonic day (ED) 13 to 15, experimental eggs were exposed to hypoxia (15 % or 17 % O₂ for 1 hr/day) while the control was at 21 % O₂. Results showed significant interactions (p = 0.040) between breeder age and oxygen level, with embryos exposed to 15 % and 17 % O₂ exhibiting slower growth by ED 17. However, embryo weight at internal pipping (IP) was unaffected (p > 0.05). At hatch, chick weights were higher in hypoxic groups due to increased yolk sac retention (p = 0.024), while yolk-free weights were influenced only by breeder age (p < 0.001). Hypoxia at 15 % O₂ reduced chick length, toe length, and tibia parameters (p < 0.05), likely due to impaired calcium and phosphorus absorption. Embryos exposed to 15 % O had longer internal and external pipping events, delaying hatch time. Embryonic mortality was highest (p < 0.001) at 15 % O₂, contributing to the reduced hatch of fertile eggs. This research demonstrates that controlled hypoxic conditions can slow embryonic development, conserve yolk nutrients, improve organ maturation and chick weight across breeder ages.
本研究考察了鸡胚尿囊绒毛膜（CAM）生长后期种鸡年龄和氧气（O₂）浓度对胚胎发育、孵化动态、雏鸡质量、骨骼矿化及孵化率的影响。选取来自33周龄和50周龄ISA蛋鸡种鸡的1200枚种蛋，平均蛋重分别为53.85克和60.42克，在37.7°C和56%相对湿度条件下孵化。从胚胎发育第13天至15天，将试验蛋暴露于低氧环境（15%或17% O₂，每天1小时），对照组为21% O₂。结果显示，种鸡年龄和氧气水平之间存在显著交互作用（p = 0.040），暴露于15%和17% O₂的胚胎在胚胎发育第17天时生长较慢。然而，内部啄壳（IP）时的胚胎重量未受影响（p > 0.05）。出雏时，由于卵黄囊保留增加，低氧组雏鸡体重较高（p = 0.024），而无卵黄体重仅受种鸡年龄影响（p < 0.001）。15% O₂的低氧环境降低了雏鸡长度、趾长和胫骨参数（p < 0.05），可能是由于钙和磷吸收受损。暴露于15% O₂的胚胎内部和外部啄壳时间延长，孵化时间推迟。胚胎死亡率在15% O₂时最高（p < 0.001），导致可育种蛋孵化率降低。本研究表明，可控的低氧条件可减缓胚胎发育、保存卵黄营养、改善各年龄种鸡的器官成熟度和雏鸡体重。
