Zhang H, Wang X T, Chamba Y, Ling Y, Wu C X
College of Animal Science and Technology, China Agricultural University, Bejing, China 100193.
Poult Sci. 2008 Oct;87(10):2112-6. doi: 10.3382/ps.2008-00122.
The experiments were conducted to assess how hatching performance is affected by chicken breeds and environment of high altitude and to analyze the vital factor of the low hatchability at a 2,900-m altitude. Eggs of Tibetan and Dwarf chickens were incubated at conditions of normobaric normoxia, normobaric hypoxia, hypobaric hypoxia, and supplemental O2 at high altitude (hypobaric normoxia) during the whole incubation or at 0 to 7, 8 to 14, and 15 to 22 d of incubation, respectively. The results showed that the Tibetan chickens had greater hatchability (79.72%), lower water loss (12.90%), greater relative embryo weight (38.08%), and relative chick weight (68.41%) compared with the Dwarf chickens (31.69, 15.79, 30.71, and 65.21%, respectively) when both of them were incubated at a 2,900-m altitude. The hatchability was 71.60% in Tibetan chicken and 36.23% in Dwarf chicken under the normobaric hypoxia condition. The hatchability of chicken was efficiently increased with supplemental O2. The previous results indicated that the O2 deficit is the main factor resulting in the low hatchability and the poor chick quality of the lowland chicken breed when incubated at a 2,900-m altitude. Breeding chickens for adaptability to hypoxia and supplemental O2 is a good way to improve the hatchability and chick quality at that altitude.
进行这些实验是为了评估鸡的品种和高海拔环境如何影响孵化性能，并分析海拔2900米处孵化率低的关键因素。藏鸡和矮小鸡的蛋分别在常压低氧、常压低氧、低氧低压以及高海拔补充氧气（低氧常压）条件下进行全程孵化，或分别在孵化的0至7天、8至14天和15至22天进行孵化。结果表明，在海拔2900米处孵化时，藏鸡的孵化率（79.72%）更高，失重（12.90%）更低，相对胚胎重量（38.08%）和相对雏鸡重量（68.41%）更大，相比之下矮小鸡的孵化率、失重、相对胚胎重量和相对雏鸡重量分别为31.69%、15.79%、30.71%和65.21%。在常压低氧条件下，藏鸡的孵化率为71.60%，矮小鸡为36.23%。补充氧气可有效提高鸡的孵化率。先前的结果表明，氧气不足是导致低地鸡品种在海拔2900米处孵化率低和雏鸡质量差的主要因素。培育适应低氧和补充氧气的种鸡是提高该海拔高度孵化率和雏鸡质量的好方法。
