Scott T R, Johnson W A, Satterlee D G, Gildersleeve R P
Poult Sci. 1981 Jun;60(6):1314-20. doi: 10.3382/ps.0601314.
Circulating levels of corticosterone were determined in chick embryos from 10 to 21 days of incubation using eggs from a Leghorn breeder flock. In Experiment 1, eggs were incubated from 10 to 20 days for daily embryonic blood collection. To verify stage of development with day of incubation, embryo right middle toe lengths were measured concurrent with blood sampling. Serum from three embryos was pooled into one sample and the corticosterone content of 10 samples per day of incubation was determined using a radioimmunoassay procedure. The levels of corticosterone from day 10 to 14 fluctuated slightly and then increased rapidly until 16 days of incubation. At this time serum corticosterone remained relatively constant through day 18 with an apparent increasing trend up to day 20. The use of toe lengths to assure no day-to-day overlap in embryonic development proved effective. In Experiment 2, newly hatched (day 21) chicks were sorted into four 3-hr periods ranging from early to late hatching. Blood samples were collected from five individual chicks during four 15-min sampling periods for each of the four hatch times. Serum corticosterone levels were not affected by sampling periods or hatch times.
利用来航种鸡群的种蛋，测定孵化10至21天的鸡胚中皮质酮的循环水平。在实验1中，将种蛋孵化10至20天，以便每天采集胚胎血液。为了根据孵化天数验证发育阶段，在采集血液的同时测量胚胎右中趾长度。将三个胚胎的血清合并为一个样本，并使用放射免疫分析程序测定孵化每天10个样本的皮质酮含量。从第10天到第14天，皮质酮水平略有波动，然后迅速上升，直至孵化第16天。此时，血清皮质酮在第18天前保持相对稳定，到第20天有明显上升趋势。利用趾长确保胚胎发育无逐日重叠被证明是有效的。在实验2中，将刚孵出（第21天）的雏鸡按孵化早晚分为四个3小时时间段。在四个孵化时间的每个时间段内，在四个15分钟的采样期采集五只雏鸡的血样。血清皮质酮水平不受采样期或孵化时间的影响。
