PDF(Pubmed)
Abstract：
Egg turning in incubation is crucial to the development of embryos and hatching performance. We aimed to develop a high performance duck egg incubation technique by enlarging and changing egg turning angles. Increasing turning angle from 45 to 75° did not affect the embryo early mortality during the first 15 d of incubation, which ranged from 3.5 to 4.0%, but accelerated chorioallantoic membrane (CAM) development by 17 h, and significantly (P < 0.01) reduced the late mortality from 9.4 ± 0.98% to 5.31 ± 0.63%. As the result, fertile egg hatchability increased from 91.03 ± 0.97% to 94.64 ± 0.61% (P < 0.05), so was healthy duckling rate from 87.24 ± 1.17% to 92.08 ± 0.55% (P < 0.05), and duckling live weight from 60.74 ± 0.63 g to 63.15 ± 0.35 g (P < 0.05). Changing turning angle from 75°to 60°during incubation d 15 to 25 further reduced late embryo mortality to 3.88 ± 0.47 and increased hatchability to 96.58 ± 0.68%. This changing angle turning hatched ducklings exhibited the highest growth performance during rearing than those hatched by 45 and 75° egg turning. The enhanced growth rate was paralleled by upregulations of somatotropic axis genes mRNA expression levels of the hypothalamus GHRH, liver GHR and IGF-1 during embryo incubation and duckling rearing. In conclusion, a changing angle egg turning incubation technique, 75°in the first 15 d and 60°thereafter, can enhance CAM development, upregulate somatotropic axis genes expressions, and can maximally improve embryo livability, duckling hatchability and growth performance.
摘要：
卵的孵化对胚胎的发育和孵化性能至关重要。我们旨在通过扩大和改变鸡蛋的旋转角度来开发一种高性能的鸭蛋孵化技术。在孵化的前15d中，从45°到75°增加转角并不影响胚胎的早期死亡率。从3.5%到4.0%不等，但是尿囊绒毛膜（CAM）的发育加速了17小时，并且显着（P<0.01）将晚期死亡率从9.4±0.98％降低到5.31±0.63％。作为结果，受精卵孵化率从91.03±0.97%提高到94.64±0.61%(P<0.05),小鸭的健康率从87.24±1.17％提高到92.08±0.55％（P<0.05），小鸭活重由60.74±0.63g增至63.15±0.35g(P<0.05)。在孵化d15至25期间将转角从75°更改为60°，进一步将晚期胚胎死亡率降低至3.88±0.47，并将孵化率提高至96.58±0.68％。这种变化的角度转弯孵化的鸭子在饲养过程中表现出比45和75°卵转弯孵化的鸭子最高的生长性能。生长速率的提高与下丘脑GHRH的促生长素轴基因mRNA表达水平的上调平行，胚胎孵化和小鸭饲养期间的肝脏GHR和IGF-1。总之,一种角度变化的卵翻转孵化技术，前15d为75°，此后为60°，可以促进CAM的发展，上调促生长素轴基因表达，可以最大限度地提高胚胎的存活率，小鸭的孵化率和生长性能。
