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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 (down) 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
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ISSN 0022-0949 ISBN Medium
Area Expedition Conference
Notes PMID:17079726 Approved no
Call Number Serial 1782
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Author Natalini, C.C.; Robinson, E.P.
Title Effects of epidural opioid analgesics on heart rate, arterial blood pressure, respiratory rate, body temperature, and behavior in horses Type Journal Article
Year 2003 Publication Veterinary Therapeutics : Research in Applied Veterinary Medicine Abbreviated Journal Vet Ther
Volume 4 Issue 4 Pages 364-375
Keywords 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/administration & dosage/pharmacology; Alfentanil/administration & dosage/pharmacology; Analgesics, Opioid/administration & dosage/*pharmacology; Anesthesia, Epidural/*veterinary; Animals; Behavior, Animal/drug effects; Blood Pressure/drug effects; Body Temperature/drug effects; Butorphanol/administration & dosage/pharmacology; Cross-Over Studies; Female; Heart Rate/drug effects; Horses/*physiology; Injections, Epidural/veterinary; Male; Morphine/administration & dosage/pharmacology; Respiration/drug effects; Tramadol/administration & dosage/pharmacology
Abstract (down) Heart rate, arterial blood pressures, respiratory rate, body temperature, and central nervous system excitement were compared before and after epidural administration of morphine (0.1 mg/kg), butorphanol (0.08 mg/kg), alfentanil (0.02 mg/kg), tramadol (1.0 mg/kg), the k-opioid agonist U50488H (0.08 mg/kg), or sterile water using an incomplete Latin square crossover design in five conscious adult horses. Treatments were administered into the first intercoccygeal epidural space. Significant (P <.05) reductions in respiratory rate were detected after epidural administration of morphine, alfentanil, U50488H, and sterile water. Additionally, significant (P <.05) head ptosis was observed within the first hour after administration of morphine, U50488H, and tramadol, but neither of these changes appeared to be of clinical significance. No treatment-related changes in motor activity or behavior were observed.
Address Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
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ISSN 1528-3593 ISBN Medium
Area Expedition Conference
Notes PMID:15136978 Approved no
Call Number Serial 1902
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Author Hughes, K.L.; Sulaiman, I.
Title The ecology of Rhodococcus equi and physicochemical influences on growth Type Journal Article
Year 1987 Publication Veterinary Microbiology Abbreviated Journal Vet Microbiol
Volume 14 Issue 3 Pages 241-250
Keywords Animals; Feces/microbiology; Horses; Hydrogen-Ion Concentration; Rhodococcus/*growth & development; *Soil Microbiology; Temperature
Abstract (down) Growth of Rhodococcus equi was studied in vitro. Optimal growth occurred under aerobic conditions between pH 7.0 and 8.5, at 30 degrees C. R. equi survived better in a neutral soil (pH 7.3) than it did in two acid soils (pH less than 5.5). It grew substantially better in soils enriched with faeces than in soils alone. Simple organic acids in horse dung, especially acetate and propionate, appear to be important in supporting growth of R. equi in the environment. The ecology of R. equi can be best explained by an environmental cycle allowing its proliferation in dung, influenced by management, grazing behaviour and prevailing climatic conditions. Preventive measures should be aimed at reducing or avoiding focal areas of faecal contamination in the environment.
Address School of Veterinary Science, University of Melbourne, Parkville, Vic., Australia
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ISSN 0378-1135 ISBN Medium
Area Expedition Conference
Notes PMID:3672866 Approved no
Call Number Equine Behaviour @ team @ Serial 2678
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Author Dyson, H.J.; Beattie, J.K.
Title Spin state and unfolding equilibria of ferricytochrome c in acidic solutions Type Journal Article
Year 1982 Publication The Journal of Biological Chemistry Abbreviated Journal J Biol Chem
Volume 257 Issue 5 Pages 2267-2273
Keywords Animals; *Cytochrome c Group; Electron Spin Resonance Spectroscopy; Heme; Horses; Hydrogen-Ion Concentration; Kinetics; Ligands; Myocardium; Protein Binding; Protein Conformation; Spectrophotometry; Temperature
Abstract (down) Equilibrium, stopped flow, and temperature-jump spectrophotometry have been used to identify processes in the unfolding of ferricytochrome c in acidic aqueous solutions. A relaxation occurring in approximately 100 microseconds involves perturbation of a spin-equilibrium between two folded conformers of the protein with methionine-80 coordinated or dissociated from the heme iron. The protein unfolds more slowly, in milliseconds, with dissociation and protonation of histidine-18. These two transitions appear cooperative in equilibrium measurements at low (0.01 M) ionic strength, but are separated at higher (0.10 M) ionic strength. They are resolved under both conditions in the dynamic measurements. The spin-equilibrium description permits a unified explanation of a number of properties of ferricytochrome c in acidic aqueous solutions.
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ISSN 0021-9258 ISBN Medium
Area Expedition Conference
Notes PMID:6277891 Approved no
Call Number Equine Behaviour @ team @ Serial 3807
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Author Duncan, I.J.H.; Widowski, T.M.; Malleau, A.E.; Lindberg, A.C.; Petherick, J.C.
Title External factors and causation of dustbathing in domestic hens Type Journal Article
Year 1998 Publication Behavioural Processes Abbreviated Journal Behav. Process.
Volume 43 Issue 2 Pages 219-228
Keywords Dustbathing; Illumination; Laying hens; Radiant heat; Social facilitation; Temperature
Abstract (down) Dustbathing is known to be motivated by complex interactions between internal factors which build up over time and external factors, such as the sight of a dusty substrate. In this study, the effects of other external factors were investigated. Environmental temperature was shown to be important; frequencies of dustbathing were greater when hens were held at 22 than at 10[degree sign]C (P<0.01). In a second experiment, a radiant heat source or a radiant heat+light source, balanced to give the same radiant heat, resulted in more dustbathing behaviour during a 1-h stimulus period than during the same period with no stimulus (P<0.05). Components of dustbathing were increased more by the heat+light stimulus than by the heat stimulus alone (P<0.03). In a third experiment, the amount of dustbathing performed by individual hens in cages with dustbaths was increased by the presence of a group of hens dustbathing in an adjoining pen with a dustbath compared with the amount occurring when the hens were absent from the pen.
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Call Number Equine Behaviour @ team @ Serial 3607
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Author Piccione, G.; Caola, G.; Refinetti, R.
Title Temporal relationships of 21 physiological variables in horse and sheep Type Journal Article
Year 2005 Publication Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology Abbreviated Journal Comp Biochem Physiol A Mol Integr Physiol
Volume 142 Issue 4 Pages 389-396
Keywords Animals; Behavior, Animal/physiology; Blood Glucose/physiology; Body Temperature/*physiology; Circadian Rhythm/*physiology; Female; Horses/*physiology; Melatonin/blood/*physiology; Motor Activity/*physiology; Rectum/physiology; Sheep/*physiology; Time Factors
Abstract (down) Daily or circadian oscillation has been documented in a variety of physiological and behavioral processes. Although individual variables have been studied in great detail, very few studies have been conducted on the temporal relationships between the rhythms of different variables. It is not known whether the circadian pacemaker generates each and every rhythm individually or whether most rhythms are simply derived from a few clock-controlled rhythms. As a first step in elucidating this issue, 21 physiological variables were recorded simultaneously in horse and sheep. The results indicated that, in both species, different variables exhibit different degrees of daily rhythmicity and reach their daily peaks at different times of the day. The variables exhibiting strongest rhythmicity were locomotor activity, rectal temperature, and plasma concentrations of melatonin and glucose. Comparison of rhythmicity and acrophase in the various rhythms allowed inferences to be made about mechanisms of causation.
Address Dipartimento di Morfologia, Biochimica, Fisiologia e Produzioni Animali, Facolta di Medicina Veterinaria, Universita degli Studi di Messina, 98168 Messina, Italy
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ISSN 1095-6433 ISBN Medium
Area Expedition Conference
Notes PMID:16290083 Approved no
Call Number Serial 1884
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Author Miksovska, J.; Larsen, R.W.
Title Photothermal studies of pH induced unfolding of apomyoglobin Type Journal Article
Year 2003 Publication Journal of Protein Chemistry Abbreviated Journal J Protein Chem
Volume 22 Issue 4 Pages 387-394
Keywords Acoustics; Animals; Apoproteins/*chemistry/metabolism; Circular Dichroism; Horses; Myocardium/chemistry; Myoglobin/*chemistry/metabolism; Photolysis; Protein Conformation/radiation effects; Protein Denaturation/radiation effects; *Protein Folding; Temperature; Thermodynamics
Abstract (down) Conformational dynamic and enthalpy changes associated with pH induced unfolding of apomyoglobin were studied using photoacoustic calorimetry and photothermal beam deflection methods. The transition between the native state and the I intermediate was induced by a nanosecond pH jump from o-nitrobenzaldehyde photolysis. Deconvolution of photoacoustic waves indicates two kinetic processes. The fast phase (T < 50 ns) is characterized by a volume expansion of 8.8 ml mol(-1). This process is followed by a volume contraction of about -22 ml mol(-1) (tau approximately 500 ns). Photothermal beam deflection measurements do not reveal any volume changes on the time scale between approximately 100 micros and 5 ms. We associate the volume contraction with structural changes occurring during the transition between the native state and the I intermediate. The lack of any processes on the ms time scale may indicate the absence of structural events involving larger conformational changes of apomyoglobin after the pH jump.
Address Department of Chemistry, University of South Florida, Tampa, Florida 33620, USA
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ISSN 0277-8033 ISBN Medium
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Notes PMID:13678303 Approved no
Call Number Equine Behaviour @ team @ Serial 3780
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Author Czerlinski, G.H.; Erickson, J.O.; Theorell, H.
Title Chemical relaxation studies on the horse liver alcohol dehydrogenase system Type Journal Article
Year 1979 Publication Physiological Chemistry and Physics Abbreviated Journal Physiol Chem Phys
Volume 11 Issue 6 Pages 537-569
Keywords Alcohol Oxidoreductases/*metabolism; Animals; Buffers; Electron Transport; Ethanol/metabolism; Horses; Hydrogen-Ion Concentration; Liver/*enzymology; Mathematics; NAD/metabolism; Oscillometry; Osmolar Concentration; Temperature; Time Factors
Abstract (down) Chemical relaxation studies on the system horse liver alcohol dehydrogenase, nicotinamide adenine dinucleotide, and ethanol were conducted observing fluorescence changes between 400 and 500 nm. Temperature-jump experiments were performed at pH 6.5, 7.0, 8.0, and 9.0; concentration-jump experiments at pH 9.0. The reciprocal of the slowest relaxation time was found to be linearly dependent upon the enzyme concentration for relatively low enzyme concentrations, as predicted earlier. Use of the wide pH-range necessitated expression of the four apparent dissociation constants of the catalytic reaction cycle in terms of pH-independent constants. The system was described in terms of only one (or two) catalysis-linked protons not associated with the electron transfer. Protonic steps in a buffered system are in rapid equilibrium, too fast to be measured with the equipment available. Assuming only two of the four bimolecular reaction steps in the four-step cycle are fast compared to the remaining two, six cases may be considered with six expressions for the reciprocal of the slowest relaxation time. Comparison with the experimental data revealed that the bimolecular reaction steps governing the slowest relaxation time change with pH. Above the effective time resolution of the temperature-lump instrument with fluorescence detection (0.1 msec) only one other relaxation time was detectable and only at pH 9. This relaxation time, found to be independent of the concentration of all reactants within experimental error (r = 10 +/- 5 msec), is most likely due to an interconversion among ternary complexes.
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ISSN 0031-9325 ISBN Medium
Area Expedition Conference
Notes PMID:44918 Approved no
Call Number Equine Behaviour @ team @ Serial 3813
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Author Shaw, E.B.; Houpt, K.A.; Holmes, D.F.
Title Body temperature and behaviour of mares during the last two weeks of pregnancy Type Journal Article
Year 1988 Publication Equine veterinary journal Abbreviated Journal Equine Vet J
Volume 20 Issue 3 Pages 199-202
Keywords Animals; *Behavior, Animal; *Body Temperature; Circadian Rhythm; Eating; Female; Horses/*physiology; Labor, Obstetric/*physiology; Motor Activity; Pregnancy; Pregnancy, Animal/*physiology
Abstract (down) Average daily core body temperature and behavioural patterns of pregnant mares were studied, in search of definitive signs of parturition within 24 h of the event. Nineteen pony mares were sampled twice daily for core body temperature. A significant temperature drop, averaging 0.1 degrees C (0.2 degrees F) was observed during the day prior to parturition. Between 18.00 h and 06.00 h, during the two weeks before parturition, Thoroughbred and Standardbred mares (n = 52) spent an average 66.8 per cent of their time standing, 27.0 per cent eating, 4.9 per cent lying in sternal recumbency, 1.0 per cent lying in lateral recumbency, and 0.3 per cent walking. On the night before parturition, mares spent significantly less time lying in sternal recumbency than on previous nights and on the night of parturition all behaviour patterns except eating were significantly different from the nights of the two weeks before parturition. There was an increase in walking (5.3 per cent), lying in sternal recumbency (8 per cent) and lying in lateral recumbency (5.3 per cent) whereas standing (53.3 per cent) was decreased. In 58 observed pregnancies, 54 mares (97 per cent) foaled in a recumbent position and 50 mares (86 per cent) foaled between 18.00 h and 06.00 h.
Address Department of Physiology, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853
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ISSN 0425-1644 ISBN Medium
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Notes PMID:3402416 Approved no
Call Number refbase @ user @ Serial 46
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Author Steinhoff, H.J.; Schrader, J.; Schlitter, J.
Title Temperature-jump studies and polarized absorption spectroscopy of methemoglobin-thiocyanate single crystals Type Journal Article
Year 1992 Publication Biochimica et Biophysica Acta Abbreviated Journal Biochim Biophys Acta
Volume 1121 Issue 3 Pages 269-278
Keywords Animals; Crystallization; Horses; Kinetics; Methemoglobin/*chemistry; Solutions; Spectrum Analysis; Temperature; Thiocyanates/*chemistry
Abstract (down) Association equilibria and association kinetics of the thiocyanate binding reaction to methemoglobin in single crystals and solution are studied using temperature-jump technique and polarized absorption spectroscopy. Different kinetic constants are found for the reaction in solution and crystal phase for the alpha- and beta-subunits of the methemoglobin tetramer. The reduction of the reactivity of the alpha- and beta-subunits in crystalline phase is 6-fold and 2.4-fold, respectively, compared to the values found in solution. The intramolecular binding reaction of the N epsilon of the distal histidine E7 which is observed in methemoglobin in solution cannot be detected in single crystals. Our results suggest that crystallization of hemoglobin has little influence on small-scale structural fluctuations which are necessary for ligands to get to the binding sites and large-scale structural motions are suppressed.
Address Institut fur Biophysik, Ruhr-Universitat Bochum, Germany
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ISSN 0006-3002 ISBN Medium
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Notes PMID:1627604 Approved no
Call Number Equine Behaviour @ team @ Serial 3800
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