Effect of nutritional substances on regulation of thermogenesis in chicken muscle

1.制度建设与完善。2002年，我国建立了一套间接式、开路量热计系统，但该系统在测量精度上存在一些问题。2003年，在呼吸室中增加了除湿器，以提高准确度。2004年，呼吸室的数量增加了，因此对选流器和控制程序进行了修改。2005年，这个系统的控制系统出现了问题，可能是因为操作系统的累积问题。因此，操作系统从Win-Me改为Win-XP，并在这次机会中修改了控制程序和混气风扇。环境温度和饮食诱导的产热(DIT)。由于饲料摄入量有限，给环境温度较低的鸡提供足够的能量并非易事。在本试验中，对低温条件下所需营养物质进行了测定。研究结果表明，通过增加饮食中的能量来维持体温，但腹水的发生率增加，可能是由于心血管功能受损，如高血压。营养素和热量的产生。研究了鸡日粮蛋白质水平与产热量的关系。蛋白质的生热效应显著，且呈剂量依赖关系，但当蛋白质含量超过20%时，不再有进一步的效应。此外，鸡的年龄似乎与产热程度有关。研究了膳食脂肪水平与产热量之间的关系。脂肪几乎没有生热作用。尽管脂肪酸被认为不是有用的呼吸底物，但醋酸盐被用作呼吸底物的速度比葡萄糖快。

1. Construction and improvement of the system. In 2002, an indirect, open-circuit calorimeter system was constructed, but this system had a little problem with the accuracy. In 2003, dehumidifiers were added to the respiratory chambers to improve accuracy. In 2004, the number of the respiratory chamber was increased, and consequently, the stream selector and control program were modified. In 2005, this system had a problem with the control system, probably because of a cumulative problem in the operating system. Therefore, the operating system was change from Win-me to Win-XP, and the control program and air-mixing fans were modified in this opportunity.2. Ambient temperature and diet-induced thermogenesis (DIT). Feeding enough energy to chickens kept at low ambient temperature is not easy, because of limited feed intake. In this experiment, required nutrients at low ambient temperature were examined. The results obtained here showed that body temperature was maintained by increased energy in diets, but incidence of ascites increased probably because of impaired cardiovascular function, such as hyper-tension.3. Nutrients and heat production. The relationship between dietary protein level and heat production in chickens was examined. Thermogenic effect of protein was remarkable and dose-dependent, but further effect was not observed when protein level exceeded 20%. In addition, the age of chickens seems to have a relation to the degree of heat production. The relationship between dietary fat level and heat production was examined. Fat had little thermogenic effect. Although fatty acids were not believed to be useful respiratory substrates, acetate was used as a respiratory substrate faster than glucose.