Department of Animal Sciences, University of Göttingen, Albrecht-Thaer-Weg 3, 37075, Göttingen, Germany.
Faculty of Science and Technology, Free University of Bolzano, Bolzano, Italy.
Sci Rep. 2017 Aug 8;7(1):7600. doi: 10.1038/s41598-017-07946-7.
Mammals typically keep their body temperature (T) within a narrow limit with changing environmental conditions. There are indications that some wild ungulates can exhibit certain forms of energy saving mechanisms when ambient temperatures are low and/or food is scarce. Therefore, the aim of the study was to determine if the llama, one of the most extensively kept domestic livestock species, exhibits seasonal adjustment mechanisms in terms of energy expenditure, T and locomotion. For that purpose llamas (N = 7) were kept in a temperate habitat on pasture. Locomotor activity, T (measured in the rumen) and the location of each animal were recorded continuously for one year using a telemetry system. Daily energy expenditure was measured as field metabolic rate (FMR). FMR fluctuated considerably between seasons with the lowest values found in winter (17.48 ± 3.98 MJ d, 402 kJ kg d) and the highest in summer (25.87 ± 3.88 MJ d, 586 kJ kg d). Llamas adjusted their energy expenditure, T and locomotor activity according to season and also time of day. Thus, llamas seem to have maintained the ability to reduce their energy expenditure and adjust their T under adverse environmental conditions as has been reported for some wild ungulates.
哺乳动物通常会在环境条件变化时将体温（T）维持在狭窄的范围内。有迹象表明，当环境温度较低和/或食物匮乏时，一些野生有蹄类动物可以表现出某些形式的节能机制。因此，本研究旨在确定作为最广泛饲养的家畜物种之一的羊驼是否在能量消耗、T 和运动方面表现出季节性调节机制。为此，我们将 7 只羊驼饲养在温带牧场环境中。使用遥测系统连续一年记录了它们的运动活动、T（在瘤胃中测量）和每只动物的位置。每日能量消耗通过体代谢率（FMR）进行测量。FMR 在季节之间波动很大，冬季最低（17.48±3.98 MJ d，402 kJ kg d），夏季最高（25.87±3.88 MJ d，586 kJ kg d）。羊驼根据季节和一天中的时间调整其能量消耗、T 和运动活动。因此，羊驼似乎保持了在不利环境条件下降低能量消耗和调节 T 的能力，这与一些野生有蹄类动物的报告一致。
