Christensen V L, Grimes J L, Wineland M J, Davis G S
Department of Poultry Science, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, North Carolina 27695-7608, USA.
Poult Sci. 2003 Dec;82(12):1869-78. doi: 10.1093/ps/82.12.1869.
The hypothesis was proposed that the improved embryonic livability observed when higher incubation temperatures were imposed on eggs stored for 15 d prior to setting might have basis in energy metabolism. To test the hypothesis, fertilized turkey eggs were incubated either for the first 2 wk of development (experiment 1) or only the first week of development (experiment 2) at 37.8 degrees C compared with controls incubated at 37.5 degrees C. In both experiments, eggs were stored for either 15 or 3 d prior to setting. Viable embryos were selected randomly from each storage-by-incubation period treatment combination at 25 to 28 d of incubation and were sampled for blood, heart, and skeletal muscle tissues. Tissues were weighed and assayed subsequently for glucose or glycogen content. In experiment 2, the randomly selected embryos from each treatment combination were sampled at 7, 14, 21, and 28 d of incubation. Embryos at 7 and 14 d were assayed on a whole body basis, whereas at 21 and 28 d the bodies were dissected, and heart, liver, and skeletal muscle tissues were weighed and assayed for glycogen and lactate. Blood samples were collected between 25 and 28 d of incubation as in experiment 1 and assayed for glucose, creatine kinase, lactate dehydrogenase, and thyroid hormone concentrations. In both experiments, accelerated development was noted due to higher temperature and enhanced embryonic carbohydrate metabolism, and elevated thyroid hormone concentrations were observed compared with controls. It was concluded that a possible mechanism for the improved livability of faster growing embryos observed after prolonged egg storage might be due to better utilization of carbohydrate.
当对孵化前储存15天的种蛋施加较高的孵化温度时，观察到胚胎存活率提高可能与能量代谢有关。为了验证这一假设，将受精火鸡种蛋在发育的前2周（实验1）或仅在发育的第一周（实验2）于37.8℃下孵化，与在37.5℃下孵化的对照组进行比较。在两个实验中，种蛋在孵化前均储存15天或3天。在孵化25至28天时，从每个储存时间与孵化期处理组合中随机选择存活胚胎，并采集血液、心脏和骨骼肌组织样本。随后对组织称重并测定葡萄糖或糖原含量。在实验2中，从每个处理组合中随机选择的胚胎在孵化7、14、21和28天时进行采样。7天和14天的胚胎进行全身测定，而在21天和28天时解剖胚胎，对心脏、肝脏和骨骼肌组织称重并测定糖原和乳酸含量。与实验1一样，在孵化25至28天时采集血液样本，测定葡萄糖、肌酸激酶、乳酸脱氢酶和甲状腺激素浓度。在两个实验中，均注意到较高温度导致发育加速以及胚胎碳水化合物代谢增强，与对照组相比，甲状腺激素浓度升高。得出的结论是，在种蛋长时间储存后观察到的生长较快胚胎存活率提高的一个可能机制可能是碳水化合物的更好利用。
