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Author Arnold, W.; Ruf, T.; Kuntz, R.
Title Seasonal adjustment of energy budget in a large wild mammal, the Przewalski horse (Equus ferus przewalskii) II. Energy expenditure Type Journal Article
Year 2006 Publication The Journal of experimental biology Abbreviated Journal J Exp Biol
Volume 209 Issue Pt 22 Pages 4566-4573
Keywords Animals; Animals, Wild/*physiology; Body Temperature; Body Temperature Regulation; Eating; *Energy Metabolism; Female; Heart Rate; Horses/*physiology; Male; Motor Activity; Pregnancy; Reproduction; *Seasons
Abstract Many large mammals show pronounced seasonal fluctuations of metabolic rate (MR). It has been argued, based on studies in ruminants, that this variation merely results from different levels of locomotor activity (LA), and heat increment of feeding (HI). However, a recent study in red deer (Cervus elaphus) identified a previously unknown mechanism in ungulates--nocturnal hypometabolism--that contributed significantly to reduced energy expenditure, mainly during late winter. The relative contribution of these different mechanisms to seasonal adjustments of MR is still unknown, however. Therefore, in the study presented here we quantified for the first time the independent contribution of thermoregulation, LA and HI to heart rate (f(H)) as a measure of MR in a free-roaming large ungulate, the Przewalski horse or Takhi (Equus ferus przewalskii Poljakow). f(H) varied periodically throughout the year with a twofold increase from a mean of 44 beats min(-1) during December and January to a spring peak of 89 beats min(-1) at the beginning of May. LA increased from 23% per day during December and January to a mean level of 53% per day during May, and declined again thereafter. Daily mean subcutaneous body temperature (T(s)) declined continuously during winter and reached a nadir at the beginning of April (annual range was 5.8 degrees C), well after the annual low of air temperature and LA. Lower T(s) during winter contributed considerably to the reduction in f(H). In addition to thermoregulation, f(H) was affected by reproduction, LA, HI and unexplained seasonal variation, presumably reflecting to some degree changes in organ mass. The observed phase relations of seasonal changes indicate that energy expenditure was not a consequence of energy uptake but is under endogenous control, preparing the organism well in advance of seasonal energetic demands.
Address Research Institute of Wildlife Ecology, University of Veterinary Medicine, Vienna, Savoyenstrasse 1, 1160 Vienna, Austria. walter.arnold@vu-wien.ac.at
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-0949 ISBN Medium
Area Expedition Conference
Notes PMID:17079726 Approved no
Call Number Serial 1782
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Author Devienne, M.F.; Guezennec, C.Y.
Title Energy expenditure of horse riding Type Journal Article
Year 2000 Publication European Journal of Applied Physiology Abbreviated Journal Eur J Appl Physiol
Volume 82 Issue 5-6 Pages 499-503
Keywords Adult; Animals; Energy Metabolism/*physiology; Exercise/*physiology; Exercise Test; Female; Hemodynamic Processes/physiology; Horses; Humans; Male; Oxygen Consumption/physiology; Respiratory Mechanics/physiology
Abstract Oxygen consumption (VO2), ventilation (VE) and heart rate (HR) were studied in five recreational riders with a portable oxygen analyser (K2 Cosmed, Rome) telemetric system, during two different experimental riding sessions. The first one was a dressage session in which the rider successively rode four different horses at a walk, trot and canter. The second one was a jumping training session. Each rider rode two horses, one known and one unknown. The physiological parameters were measured during warm up at a canter in suspension and when jumping an isolated obstacle at a trot and canter. This session was concluded by a jumping course with 12 obstacles. The data show a progressive increase in VO2 during the dressage session from a mean value of 0.70 (0.18) l x min(-1) [mean (SD)] at a walk, to 1.47 (0.28) l x min(-1) at a trot, and 1.9 (0.3) l x min(-1) at a canter. During the jumping session, rider VO2 was 2 (0.33) l x min(-1) with a mean HR of 155 beats x min(-1) during canter in suspension, obstacle trot and obstacle canter. The jumping course significantly enhanced VO2 and HR up to mean values of 2.40 (0.35) l x min(-1) and 176 beats x min(-1), respectively. The comparison among horses and riders during the dressage session shows differences in energy expenditure according to the horse for the same rider and between riders. During the jumping session, there was no statistical difference between riders riding known and unknown horses. In conclusion these data confirm that riding induces a significant increase in energy expenditure. During jumping, a mean value of 75% VO2max was reached. Therefore, a good aerobic capacity seems to be a factor determining riding performance in competitions. Regular riding practice and additional physical training are recommended to enhance the physical fitness of competitive riders.
Address Universite Paris XII-STAPS-61, Creteil, France. Mfdevienne@aol.com
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1439-6319 ISBN Medium
Area Expedition Conference
Notes PMID:10985607 Approved no
Call Number Equine Behaviour @ team @ Serial 3731
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Author Gutierrez Rincon, J.A.; Vives Turco, J.; Muro Martinez, I.; Casas Vaque, I.
Title A comparative study of the metabolic effort expended by horse riders during a jumping competition Type Journal Article
Year 1992 Publication British Journal of Sports Medicine Abbreviated Journal Br J Sports Med
Volume 26 Issue 1 Pages 33-35
Keywords Adult; Animals; Energy Metabolism/*physiology; *Exertion; Heart Rate/physiology; Horses; Humans; Lactates/blood; *Sports
Abstract The three main Olympic horse riding disciplines are dressage, jumping, and three-day eventing (including dressage, cross country and jumping). In the jumping discipline (obstacle race), the 'team' (horse rider) is judged under the different conditions that might take place in a varied run. The horse is expected to show power and ability; the rider must show riding skill and good physical condition. However, the different conditions encountered by the rider during competition (duration of event, continuous isometric working level, especially in the inferior trunk, lead us to consider the need for a rider to develop different metabolic pathways to meet the high energy requirements of the competition.
Address Centre de Medicina de l'Esport de Barcelona, Spain
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0306-3674 ISBN Medium
Area Expedition Conference
Notes PMID:1600451 Approved no
Call Number Equine Behaviour @ team @ Serial 3754
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Author Jansen, W.L.; van Alphen, M.; Berghout, M.; Everts, H.; Beynen, A.C.
Title An approach to assessment of the efficiency of dietary energy utilization by horses and ponies kept at riding schools Type Journal Article
Year 2001 Publication The Veterinary quarterly Abbreviated Journal Vet Q
Volume 23 Issue 4 Pages 195-198
Keywords *Animal Feed; Animal Husbandry; Animals; Body Weight; Dietary Fats; Dietary Fiber; *Energy Intake; *Energy Metabolism; Female; Horses/*physiology; Male
Abstract The ratio of calculated net energy intake (NEi) to calculate net energy requirement (NEr) might serve as an indicator of the efficiency of dietary energy utilization. The ratio was determined for 93 horses and ponies from 10 riding schools. For each animal with an assumed constant body weight, energy intake and energy requirements were assessed. On average, the estimated NEi was 14% greater than NEr. There was a significant, negative association between crude fibre intake and the NEi: NEr ratio. Earlier work indicated that extra fat intake may lead to over estimation of the calculated energy value of the ration due to changes in macronutrient digestibility. Dietary fat concentration was found to range from 32 to 52 g/kg dry matter (5 to 6 g/MJ net energy), but on the basis of digestibility trials this range in fat concentration is too small to significantly influence the NEi: NEr ratio. This study shows that assessment of the efficiency of dietary energy utilization under normal conditions, on the basis of the NEi: NEr ratio is fraught with uncertainty.
Address Department of Nutrition, Faculty of Veterinary, Medicine, Utrecht University, The Netherlands
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0165-2176 ISBN Medium
Area Expedition Conference
Notes PMID:11765239 Approved no
Call Number Serial 1807
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Author Ralston, S.L.
Title Controls of feeding in horses Type Journal Article
Year 1984 Publication Journal of Animal Science Abbreviated Journal J. Anim Sci.
Volume 59 Issue 5 Pages 1354-1361
Keywords Animal Feed; Animals; Digestive Physiology; Energy Metabolism; Feeding Behavior/*physiology; Food Preferences; Horses/*physiology; Oropharynx/physiology; Satiation/physiology; Smell; Taste
Abstract Members of the genus Equus are large, nonruminant herbivores. These animals utilize the products of both enzymatic digestion in the small intestine and bacterial fermentation (volatile fatty acids) in the cecum and large colon as sources of metabolizable energy. Equine animals rely primarily upon oropharyngeal and external stimuli to control the size and duration of an isolated meal. Meal frequency, however, is regulated by stimuli generated by the presence and (or) absorption of nutrients (sugars, fatty acids, protein) in both the large and small intestine plus metabolic cues reflecting body energy stores. The control of feeding in this species reflects its evolutionary development in an environment which selected for consumption of small, frequent meals of a variety of forages.
Address
Corporate Author Thesis
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8812 ISBN Medium
Area Expedition Conference
Notes PMID:6392275 Approved no
Call Number refbase @ user @ Serial 1954
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Author Rands, S.A.; Cowlishaw, G.; Pettifor, R.A.; Rowcliffe, J.M.; Johnstone, R.A.
Title Spontaneous emergence of leaders and followers in foraging pairs Type Journal Article
Year 2003 Publication Nature Abbreviated Journal Nature
Volume 423 Issue 6938 Pages 432-434
Keywords Animals; *Energy Metabolism; Food; *Food Chain; *Models, Biological; Motor Activity; *Social Behavior; Time Factors
Abstract Animals that forage socially often stand to gain from coordination of their behaviour. Yet it is not known how group members reach a consensus on the timing of foraging bouts. Here we demonstrate a simple process by which this may occur. We develop a state-dependent, dynamic game model of foraging by a pair of animals, in which each individual chooses between resting or foraging during a series of consecutive periods, so as to maximize its own individual chances of survival. We find that, if there is an advantage to foraging together, the equilibrium behaviour of both individuals becomes highly synchronized. As a result of this synchronization, differences in the energetic reserves of the two players spontaneously develop, leading them to adopt different behavioural roles. The individual with lower reserves emerges as the 'pace-maker' who determines when the pair should forage, providing a straightforward resolution to the problem of group coordination. Moreover, the strategy that gives rise to this behaviour can be implemented by a simple 'rule of thumb' that requires no detailed knowledge of the state of other individuals.
Address Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK. s.rands@zoo.cam.ac.uk
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0028-0836 ISBN Medium
Area Expedition Conference
Notes PMID:12761547 Approved no
Call Number Equine Behaviour @ team @ Serial 5138
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