Many researches about in ovo feeding (IOF) of vitamin C (VC) are gradually carried out to explore physiological development in chicken, but little studies focus on VC synthesis capacity of the embryo itself, the selection of injection site and the effectiveness of IOF of VC. This study aims to explore the above problems. Kidney and yolk sac were the main organs for VC synthesis and L-gulonolactone oxidase (GLO) expression was lower during pre-hatch development than that during post-hatch development. Sodium-dependent vitamin C transporter 1 (SVCT1) expression was increased continuously in yolk sac from embryonic age 19 (E19) to post-hatch day 1 (D1) and in intestine (duodenum, jejunum and ileum) from E17 to D1. Plasma VC content was higher at D1 than that at D21 and D42. IOF of VC significantly reduced GLO expression in liver, kidney and yolk sac as well as SVCT1 expression in duodenum, jejunum and ileum, but increased the VC content in plasma, brain, kidney and liver. In addition, IOF of VC obviously reduced the embryonic morality and increased the hatchability under heat stress. This study suggested that IOF of VC at E11 in yolk was effective for embryonic VC supplementation. These findings provide a theoretical reference about the method of embryonic VC supplementation and effective methodology on embryonic VC nutrition in broiler chickens.

中文翻译：

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基于肉鸡胚胎维生素C的合成和吸收探索维生素C卵内饲喂的有效性

维生素C（VC）卵内喂养（IOF）的研究逐渐开展，以探索鸡的生理发育，但对胚胎本身VC合成能力、注射部位的选择以及IOF有效性的研究较少。 VC。本研究旨在探讨上述问题。肾脏和卵黄囊是VC合成的主要器官，孵化前发育期间L-古洛糖酸内酯氧化酶(GLO)表达低于孵化后发育期间。钠依赖性维生素 C 转运蛋白 1 (SVCT1) 在卵黄囊中从胚胎 19 龄 (E19) 到孵化后第 1 天 (D1) 以及在肠道（十二指肠、空肠和回肠）中从 E17 到 D1 持续增加。D1 时血浆 VC 含量高于 D21 和 D42 时。VC的IOF显着降低了肝、肾和卵黄囊中GLO的表达以及十二指肠、空肠和回肠中SVCT1的表达，但增加了血浆、脑、肾和肝脏中的VC含量。此外，VC的IOF明显降低了胚胎道德，提高了热应激下的孵化率。这项研究表明，卵黄中 E11 的 VC IOF 对于胚胎 VC 补充是有效的。这些研究结果为肉鸡胚胎VC补充方法和胚胎VC营养的有效方法提供了理论参考。