Investigations on seasonal differences in the energy allocation of free ranging llamas (Lama glama) under Central European and high altitude Andean conditions

吸热型动物必须随着环境条件的变化而将体温保持在一个狭窄的范围内。然而，这是以高昂的能源成本为代价的。然而，有迹象表明，当环境温度较低和/或食物供应稀缺时，一些有蹄类动物可以表现出某种形式的节能机制。这一现象在大型有蹄类动物如马鹿、马鹿以及马匹的野生祖先普氏野马身上都有表现。有人推测，牲畜物种在食物短缺和/或不利的环境条件下失去了减少能量消耗的能力，因为它们是在持续的营养供应下饲养和选择的，没有选择压力，以维持季节性的循环适应。然而，与野生物种相比，家畜物种的适应性据说较低，这一点的经验证实仍然缺乏。此外，在广泛饲养的牲畜物种中，关于能量分配的这种季节性调整在多大程度上仍然是未知的。在这方面，骆驼特别适合作为模式动物，因为它代表了最健壮的家畜品种之一，在驯化模式之后，可以被称为初级种群。因此，这项研究的目的是确定在中欧和高海拔安第斯气候条件下，作为饲养最广泛的家畜品种之一的骆驼，在能量消耗和运动方面是否表现出季节性调节机制。这项拟议中的研究将是哺乳动物的第一项研究，它将双标记水法测量能量消耗与遥测系统相结合，测量运动、体温和心率，并确定GPS覆盖的距离。结合起来，这些数据将给出关于动物能量消耗和能量节省之间相互作用的非常详细的图景。

Endothermic animals have to keep their body temperature within a narrow limit with changing environmental conditions. However, this comes at a high energetic cost. Nevertheless, there are indications that some ungulates can exhibit some form of an energy saving mechanism when ambient temperatures are low and/or food availability is scarce. This phenomenon has been shown for large ungulates such as roe deer, red deer and for the wild ancestor of the horse, the Przewalski horse. There are speculations that livestock species lost the ability to reduce their energy expenditure under food shortages and/or adverse environmental conditions, since they were housed and selected under constant nutrient supply without selection pressure for maintaining a seasonal, cyclic adaptation. However, empirical confirmation of a supposedly lower adaptability of livestock species compared to their wild counterparts is still missing. Furthermore, it is still unknown to what extend such seasonal adjustments with regard to energy allocation are present in extensively kept livestock species. In that regard the llama is particularly well suited as a model animal since it represents one of the most robust domestic animal breeds which, after the domestication model, can be referred to as a primary population. Therefore, the aim of the study is to determine if the llama, one of the most extensively kept livestock breeds, exhibits seasonal adjustment mechanisms in terms of energy expenditure and locomotion under Central European and high altitude Andean climatic conditions. The proposed study would be the first in a mammal that combines the doubly labelled water method for measuring energy expenditure with a telemetry system measuring locomotion, body temperature and heart rate, as well as determining the distances covered by a GPS. In combination these data will give a very detailed picture about the interaction between energy expenditure and energy savings in an animal.