Faeces is a reliable source of body water for measuring tritium in reindeer in summer and in winter

  • Geir Gotaas Department of Arctic Biology and Institute of Medical Biology, University of Tromsø, N-9037 Tromsø, Norway
  • Nicholas J.C. Tyler Present address: Department of Ecology/Zoology, Institute of Biology and Geology, University of Tromsø, N-9037 Tromsø, Norway
Keywords: reindeer, tritium, plasma, rumen fluid, isotope markers, water turnover, seasonal physiology

Abstract

Rates of equilibration and subsequent wash-out of tritium were measured in parallel samples of blood, rumen fluid and faeces collected from two adult female Norwegian reindeer in summer and in winter. The tritium-concentration was the same in all three body water compartments after no more than 9 h following both intravenous and intra-ruminal injection of isotope in summer and following intravenous injection of isotope in winter. The biological half-life of the tritium increased from approximately 3 days in summer to approximately 10 days in winter, probably as a consequence of a decrease in water intake. There were no significant differences in disappearance rates of tritium from blood, rumen fluid and faeces within any of the six experiments. Fresh faeces is therefore a reliable source of body water that can be used in place of blood in studies of body water kinetics in reindeer, thus making it potentially possible to conduct such studies on truly free-living and undisturbed animals.
Published
1995-01-01
How to Cite
GotaasG., & TylerN. J. (1995). Faeces is a reliable source of body water for measuring tritium in reindeer in summer and in winter. Rangifer, 15(2), 63-70. https://doi.org/10.7557/2.15.2.1168
Section
Articles