QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online November 1, 2006
Journal of Experimental Biology 209, 4557-4565 (2006)
Published by The Company of Biologists 2006
doi: 10.1242/jeb.02535

This Article Figures Only Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kuntz, R. Articles by Arnold, W. Search for Related Content PubMed PubMed Citation Articles by Kuntz, R. Articles by Arnold, W.

Seasonal adjustment of energy budget in a large wild mammal, the Przewalski horse (Equus ferus przewalskii) I. Energy intake

Regina Kuntz, Christina Kubalek, Thomas Ruf, Frieda Tataruch and Walter Arnold^*

Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Savoyenstraße 1, 1160 Vienna, Austria

^* Author for correspondence (e-mail: walter.arnold{at}vu-wien.ac.at)

Accepted 8 September 2006

Large ruminants respond to changing plant phenology during winter by decreasing voluntary food intake, increasing gut passage time and utilizing body fat reserves. It is uncertain, however, how other large mammals with a non-ruminant digestive physiology cope with winter forage conditions. Therefore, we investigated seasonality of energy intake in a large herbivorous wild mammal, the Przewalski horse (Equus ferus przewalskii). Throughout all seasons we used the n-alkane method to measure daily dry matter intake (DMI), diet composition and digestion, and determined an index of gut passage time in horses living under close to natural conditions.

DMI correlated positively with its content of crude protein and nitrogen-free extract. Independent of these effects, DMI further varied seasonally with a peak in autumn and a nadir in late winter. Fluctuations of DMI corresponded to the annual change in body condition, which decreased during winter while energy reserves were depleted, and increased during the fattening period. Gut passage time varied in the course of the year and was longer during winter when the diet was high in crude fibre. Nevertheless, changes in gut passage time occurred rather independently of changes in forage composition and DMI, suggesting endogenous control for timely adaption of the digestive strategy to meet predictable changes in forage quality.

Key words: annual rhythm, body mass, dry matter intake, food composition, digestibility, gut passage time, n-alkane method

This article has been cited by other articles:

				C. A. Wyse, K. A. McNie, V. J. Tannahil, J. K. Murray, and S. Love Prevalence of obesity in riding horses in Scotland Vet Rec., May 3, 2008; 162(18): 590 - 591. [Full Text] [PDF]

				W. Arnold, T. Ruf, and R. Kuntz Seasonal adjustment of energy budget in a large wild mammal, the Przewalski horse (Equus ferus przewalskii) II. Energy expenditure J. Exp. Biol., November 15, 2006; 209(22): 4566 - 4573. [Abstract] [Full Text] [PDF]