Bowen S J, Washburn K W
Poult Sci. 1985 Jan;64(1):149-54. doi: 10.3382/ps.0640149.
Three experiments were conducted to evaluate the thyroid and adrenal response in groups of birds with altered heat tolerance. Groups of chickens that had been handled on each of 4 days and a nonhandled control group were bled on the 5th day with or without heating for 1 hr at 50 C. Handling did not affect the thyroid response as indicated by thyroxine (T4) or triiodothyronine (T3) levels. Corticosterone levels were lower in handled birds than nonhandled birds after heating. In a second experiment, groups of broilers were fed a diet containing .2% thiouracil or a control diet. After 2 weeks they were bled either with or without 1 hr of heating at 50 C. The T3 and T4 levels were reduced by thiouracil feeding both with and without heating, but adrenal function was not affected. In Experiment 3, T3 and T4 levels were compared for four lines of Japanese quail. The nongrowth-selected line had higher T3 and T4 levels than growth-selected lines but did not have elevated levels of T3 or T4 in response to heat stress. The growth-selected lines (T, S, and P) responded to heating with increased T3 and T4 levels. Levels of T4 in Line T (selected on a thiouracil diet) after heating were significantly higher than all other lines.
进行了三项实验，以评估耐热性改变的鸟类群体的甲状腺和肾上腺反应。将在4天中的每一天都经过处理的几组鸡和一个未处理的对照组在第5天进行采血，采血时有的进行或不进行在50℃下1小时的加热处理。如甲状腺素（T4）或三碘甲状腺原氨酸（T3）水平所示，处理并未影响甲状腺反应。加热后，经过处理的鸡的皮质酮水平低于未处理的鸡。在第二项实验中，给几组肉鸡喂食含0.2%硫脲的日粮或对照日粮。2周后，对它们进行采血，采血时有的进行或不进行在50℃下1小时的加热处理。无论加热与否，硫脲喂养都会降低T3和T4水平，但肾上腺功能未受影响。在实验3中，比较了四系日本鹌鹑的T3和T4水平。未经过生长选择的品系的T3和T4水平高于经过生长选择的品系，但对热应激无T3或T4水平升高的反应。经过生长选择的品系（T、S和P）对加热的反应是T3和T4水平升高。加热后，品系T（在硫脲日粮上选择）的T4水平显著高于所有其他品系。
