Analyze Diet

Topic:Stress

Stress in horses refers to the physiological and behavioral responses of equines to various stressors, including environmental changes, social dynamics, and physical exertion. These responses can manifest through alterations in heart rate, cortisol levels, and behavior, among other indicators. Stress can affect a horse's overall health, performance, and welfare, making it a significant area of study in equine research. This topic encompasses research on identifying stressors, measuring stress responses, and understanding the implications of stress on equine health and behavior. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, effects, and management of stress in horses.
Stress response to chronic inflammation in the horse.
Equine veterinary journal    December 31, 1997   Volume 29, Issue 6 483-486 doi: 10.1111/j.2042-3306.1997.tb03163.x
Mills PC, Ng JC, Kramer H, Auer DE.Five clinically healthy Thoroughbred geldings were injected with Freund's adjuvant 3 times to induce a chronic inflammatory response. Blood was collected at various times before and after adjuvant administration. Clinical responses (rectal temperature and general demeanor) were also monitored. Adjuvant injection induced increases in rectal temperature and plasma fibrinogen concentration (maximum levels measured were mean +/- s.d. 39.7 +/- 0.5 degrees C and 8.2 +/- 0.3 g/l, respectively), indicative of an inflammatory response. A mild clinical depression was also observed in the horses for 24 h...
Development and validation of a series of three-dimensional finite element models of the equine metacarpus.
Journal of biomechanics    July 1, 1997   Volume 30, Issue 7 737-742 doi: 10.1016/s0021-9290(97)00007-9
Les CM, Keyak JH, Stover SM, Taylor KT.Three-dimensional finite element (FE) models of the left metacarpi of five adult horses were developed from quantitative computed tomography data, using the algorithms of Keyak et al. (1990, J Biomed. Engng 12, 389-397). The metacarpi were then equipped with 12 rosette strain gauges and loaded non-destructively in a mechanical testing machine. The bones and the models were loaded in axial compression, with the load evenly distributed across the distal row of carpal bones, and with a point load placed mediad to the sagittal midline, to a load equivalent to three times body weight (-15 kN); and ...
Additional research on tendon strains and stresses.
American journal of veterinary research    June 1, 1997   Volume 58, Issue 6 569-570 
Crevier-Denoix N, Pourcelot P.No abstract available
Catecholamines, enkephalins and the response of the fetal adrenal medulla to hypoxaemia.
Equine veterinary journal. Supplement    June 1, 1997   Issue 24 68-73 doi: 10.1111/j.2042-3306.1997.tb05081.x
McMillen IC, Simonetta G, Roberts ML, Adams MB.No abstract available
Effect of transportation on lower respiratory tract contamination and peripheral blood neutrophil function.
Australian veterinary journal    June 1, 1997   Volume 75, Issue 6 433-438 doi: 10.1111/j.1751-0813.1997.tb14349.x
Raidal SL, Bailey GD, Love DN.To evaluate the effect of transportation on lower respiratory tract contamination and peripheral blood neutrophil function in horses and to compare results from transported horses with those obtained in earlier experiments from horses confined with heads elevated. Methods: A prospective study. Methods: Six horses were transported by road for 12 h. Clinical and haematological examination, transtracheal aspiration and cell function studies were conducted before and after transportation. Results obtained after transportation were compared to pre-transportation values. Results: After transportatio...
Cortisol concentrations in post competition horse urine: a French and British survey.
Equine veterinary journal    May 1, 1997   Volume 29, Issue 3 226-229 doi: 10.1111/j.2042-3306.1997.tb01673.x
Popot MA, Houghton E, Ginn A, Jones M, Teale P, Samuels T, Lassourd V, Dunnett N, Cowan DA, Bonnaire Y, Toutain PL.The purpose of the present report was to estimate the population parameters of cortisol concentrations in urine, an endogenous hormone used as a 'doping' agent and for which an international threshold (1.0 micrograms/ml) has been proposed. Two data bases (French and UK) corresponding to 112 and 142 samples, respectively were considered. Urine was collected under specific post competition conditions. Cortisol concentrations were obtained by validated methods (HPLC for the French samples, and GC-MS for UK samples). No difference was observed between the 2 data sets and statistical analyses were ...
Very high pressures are required to cause stress failure of pulmonary capillaries in thoroughbred racehorses.
Journal of applied physiology (Bethesda, Md. : 1985)    May 1, 1997   Volume 82, Issue 5 1584-1592 doi: 10.1152/jappl.1997.82.5.1584
Birks EK, Mathieu-Costello O, Fu Z, Tyler WS, West JB.Thoroughbred horses develop extremely high pulmonary vascular pressures during galloping, all horses in training develop exercise-induced pulmonary hemorrhage, and we have shown that this is caused by stress failure of pulmonary capillaries. It is known that the capillary transmural pressure (Ptm) necessary for stress failure is higher in dogs than in rabbits. The present study was designed to determine this value in horses. The lungs from 15 Thoroughbred horses were perfused with autologous blood at Ptm values (midlung) of 25, 50, 75, 100 and 150 mmHg, and then perfusion fixed, and samples (d...
Mechanical properties of pathological equine superficial digital flexor tendons.
Equine veterinary journal. Supplement    May 1, 1997   Issue 23 23-26 doi: 10.1111/j.2042-3306.1997.tb05046.x
Crevier-Denoix N, Collobert C, Pourcelot P, Denoix JM, Sanaa M, Geiger D, Bernard N, Ribot X, Bortolussi C, Bousseau B.The objective of this study was to mechanically characterise superficial digital flexor tendon (SDFT) lesions. Eight pathological SDFTs, isolated from 6 adult horses, were tested in traction until rupture (at 1 mm/s). The stresses and strains simultaneously undergone by each of the 7 segments of a tendon were determined throughout the test, and the modulus of elasticity of each segment was evaluated from the segmental stress-strain curve thus obtained. These mechanical data were compared to those obtained on 10 normal SDFTs. After the test, the tendinous segments were submitted to a histologic...
Plasma glucose and cortisol responses to exogenous insulin in fasted donkeys.
Research in veterinary science    May 1, 1997   Volume 62, Issue 3 265-269 doi: 10.1016/s0034-5288(97)90202-2
Forhead AJ, Dobson H.Susceptibility to equine hyperlipaemia is increased by poor food intake. To assess the contribution of changes in insulin sensitivity, plasma glucose and cortisol responses to an intravenous insulin challenge (0.4 IU kg-1 bodyweight) were compared with those observed after saline administration in six donkeys fasted either overnight or for three days. Three days of fasting decreased both the rate of insulin-induced hypoglycemia and the maximal hypoglycemic response. A transitory increase in plasma cortisol which peaked within one to four hours of insulin administration was observed in three of...
Residual strength of equine bone is not reduced by intense fatigue loading: implications for stress fracture.
Journal of biomechanics    February 1, 1997   Volume 30, Issue 2 109-114 doi: 10.1016/s0021-9290(96)00113-3
Martin RB, Gibson VA, Stover SM, Gibeling JC, Griffin LV.Fatigue or stress fractures are an important clinical problem in humans as well as racehorses. An important question in this context is, when a bone experiences fatigue damage during extreme use, how much is it weakened compared to its original state? Since there are very limited data on this question and stress fractures are common in racehorses, we sought to determine the effect of fatigue loading on the monotonic strength of equine cortical bone. Beams were machined from the dorsal, medial and lateral cortices of the third metacarpal bones of six thoroughbred racehorses. Beams from left and...
The effect of detomidine and its antagonism with tolazoline on stress-related hormones, metabolites, physiologic responses, and behavior in awake ponies.
Veterinary surgery : VS    January 1, 1997   Volume 26, Issue 1 69-77 doi: 10.1111/j.1532-950x.1997.tb01467.x
Carroll GL, Matthews NS, Hartsfield SM, Slater MR, Champney TH, Erickson SW.Six ponies were used to investigate the effect of tolazoline antagonism of detomidine on physiological responses, behavior, epinephrine, norepinephrine, cortisol, glucose, and free fatty acids in awake ponies. Each pony had a catheter inserted into a jugular vein 1 hour before beginning the study. Awake ponies were administered detomidine (0.04 mg/kg intravenously [i.v.]) followed 20 minutes later by either tolazoline (4.0 mg/kg i.v.) or saline. Blood samples were drawn from the catheter 5 minutes before detomidine administration (baseline), 5 minutes after detomidine administration, 20 minute...
[The effect of the season and sexual stress on the concentration of testosterone and estradiol-17beta in the seminal plasma of stallions].
Tierarztliche Praxis    December 1, 1996   Volume 24, Issue 6 577-580 
Braun J, Muto Y, Sato K, Schallenberger E.Semen from three stallions was collected weekly for six months (December through May) to determine semen parameters and hormones (testosterone and estradiol-17 beta) in seminal plasma. Once a month three ejaculates were collected at intervals of one hour and examined accordingly. Testosterone and estradiol-17 beta were also determined in peripheral blood plasma (V. jugularis) collected twice a week. Semen parameters (volume, gel-free volume and sperm concentration) were clearly influenced by season. The testosterone concentration in peripheral blood plasma was lowest during December whereas in...
Effects of road transport on indices of stress in horses.
Equine veterinary journal    November 1, 1996   Volume 28, Issue 6 446-454 doi: 10.1111/j.2042-3306.1996.tb01616.x
Smith BL, Jones JH, Hornof WJ, Miles JA, Longworth KE, Willits NH.Stress associated with road transport is believed to be a significant contributor to the pathogenesis of post transport respiratory disease in horses. To determine the effects of road transport on pulmonary function, pulmonary aerosol clearance rates were measured in 4 horses 24 h before, and immediately after, 24 h of road transport by delivering aerosolised 99mtechnetium-labelled diethylenetriaminepentacetate (99mTc-DTPA) to the lungs and monitoring its washout. Each horse was transported twice, once while the trailer was equipped with a leaf-spring suspension and bias-ply tyres (trailer's o...
Exercise and immunity: a review with emphasis on the horse.
Journal of veterinary internal medicine    September 1, 1996   Volume 10, Issue 5 280-289 doi: 10.1111/j.1939-1676.1996.tb02063.x
Hines MT, Schott HC, Bayly WM, Leroux AJ.Exercise has been recognized as a stress, which can significantly alter the host's immune response and, therefore, its susceptibility to disease. Whereas research in this area has previously focused primarily on human subjects and laboratory animals, it has more recently extended to domestic animals, especially the equine athlete. Despite several studies, defining the relationship among exercise, the immune response, and disease has proven difficult due to a number of factors, including the complexity of the immune system and the variable nature of exercise itself. It now appears that exercise...
The effect of hole diameter on the torsional mechanical properties of the equine third metacarpal bone.
Veterinary surgery : VS    September 1, 1996   Volume 25, Issue 5 371-375 doi: 10.1111/j.1532-950x.1996.tb01429.x
Seltzer KL, Stover SM, Taylor KT, Willits NH.The torsional monotonic structural material properties of equine metacarpi with or without, either a 5/16 inch or 3/8 inch diameter bicortical lateromedial middiaphyseal hole were assessed to determine the effect of a hole on metacarpal strength. Torsional stiffness was not significantly effected by the presence of a bicortical hole, whereas yield and failure angles, torques and energies of metacarpi with a hole were 51% to 97% of those of intact bones. Significant differences were not apparent for yield and failure mechanical properties between metacarpi with a 5/16 inch diameter hole and met...
Segmental variations of in vitro mechanical properties in equine superficial digital flexor tendons.
American journal of veterinary research    August 1, 1996   Volume 57, Issue 8 1111-1117 
Crevier N, Pourcelot P, Denoix JM, Geiger D, Bortolussi C, Ribot X, Sanaa M.To determine the local variations of mechanical properties of the equine superficial digital flexor tendon (SDFT). Methods: 10 SDFT of adult horses, selected for absence of abnormality. Methods: Needles (with a dark marker at both ends) pinned perpendicularly through each tendon to delimit 7 segments. Each tendon was tested in traction until rupture; test was filmed, using an 8-mm video camera. For each image, the coordinates of the center of mass of each marker and the corresponding force were registered. The third-degree polynomial that best fits the stress-strain curve thus obtained was cal...
Effects of transporting horses facing either forwards or backwards on their behaviour and heart rate.
The Veterinary record    July 6, 1996   Volume 139, Issue 1 7-11 doi: 10.1136/vr.139.1.7
Waran NK, Robertson V, Cí·¯ord D, Kokoszko A, Marlin DJ.The effects of transporting horses facing either forwards or backwards were compared by transporting six thoroughbred horses in pairs in a lorry on one journey facing in the direction of travel, and on another journey facing away from the direction of travel, over a standard one-hour route. Heart rate monitors were used to record their heart rate before, during and after the journey and the horses' behaviour was recorded by scan sampling each horse every other minute. The average heart rate was significantly lower (P < 0.05) when the horses were transported facing backwards, and they also t...
Cortisol disposition and production rate in horses during rest and exercise.
The American journal of physiology    July 1, 1996   Volume 271, Issue 1 Pt 2 R25-R33 doi: 10.1152/ajpregu.1996.271.1.R25
Lassourd V, Gayrard V, Laroute V, Alvinerie M, Benard P, Courtot D, Toutain PL.The influence of a 56-km endurance exercise on cortisol kinetics and production rate was evaluated in six horses administered [3H]cortisol. Exercise resulted in an immediate two- to threefold increase in plasma cortisol, with values returning very rapidly to preexercise levels. During exercise, clearance and steady-state volume of distribution of total cortisol were greatly increased (338 +/- 95 vs. 137 +/- 34 ml.kg-1.h-1 for clearance and 359 +/- 82 vs. 229 +/- 18 ml/kg for volume of distribution), whereas the terminal half-life decreased significantly (0.97 +/- 0.16 vs. 1.55 +/- 0.33 h). The...
Use of adverse conditions to stimulate a cellular stress response by equine articular chondrocytes.
American journal of veterinary research    June 1, 1996   Volume 57, Issue 6 860-865 
Benton HP, Cheng TC, MacDonald MH.To determine the response of equine articular cartilage cells to heat and calcium stresses. Methods: Analysis of newly synthesized, [35S]methionine-labeled proteins after treatment of isolated primary equine chondrocytes. Methods: Primary cultures of equine articular chondrocytes were incubated at temperatures ranging from 37 to 42 C for heat stress experiments or incubated in the presence or absence of the intracellular calcium pump inhibitor, thapsigargin, for calcium stress experiments. Patterns of new protein synthesis were determined by incubating with [35S]methionine followed by separati...
Strain-rate-dependent mechanical properties of the equine hoof wall.
The Journal of experimental biology    May 1, 1996   Volume 199, Issue Pt 5 1133-1146 doi: 10.1242/jeb.199.5.1133
Kasapi MA, Gosline JM.The mechanical properties of fully hydrated equine hoof wall were examined at various loading rates in compact tension (CT) fracture, tensile and three-point bending dynamic tests to determine possible effects of hoof wall viscoelasticity on fracture toughness and tensile parameters. Four cross-head rates were used in CT tests: 1.7 x 10(-5), 1.7 x 10 (-3), 1.7 x 10(-2) and 2.5ms-1; four strain rates were used in tensile tests: 1.6 x 10(-3), 3.2 x 10(-2), 0.33 and 70s(-1). Speeds for the highest test rates were achieved using a large, custom-built impact pendulum. Bending test frequencies range...
[‘Weaving’ in horses].
Tijdschrift voor diergeneeskunde    March 1, 1996   Volume 121, Issue 5 145-146 
Breukink HJ.No abstract available
The integrative control of adrenocorticotrophin secretion: a critical role for corticotrophin-releasing hormone.
The Journal of endocrinology    March 1, 1996   Volume 148, Issue 3 475-483 doi: 10.1677/joe.0.1480475
Evans MJ, Mulligan RS, Livesey JH, Donald RA.Perifused equine anterior pituitary cells were used to investigate the relationships between the secretion of ACTH and substances known to either stimulate (corticotrophin-releasing hormone (CRH), and arginine vasopressin (AVP)) or inhibit (cortisol) ACTH secretion. The experiments were designed to mimic the hormone milieu present in vivo in the horse, with cortisol (0 or 100 nmol/l) and CRH (0 or 0.02 nmol/l) perifused continuously, and pulses of AVP (10 nmol/l) applied for 5 min at 30-min intervals. In columns perifused with 0.02 nmol CRH/l there was no significant overall effect of 100 nmol...
Dynamics of the regulation of the hypothalamo-pituitary-adrenal (HPA) axis determined using a nonsurgical method for collecting pituitary venous blood from horses.
Frontiers in neuroendocrinology    January 1, 1996   Volume 17, Issue 1 1-50 doi: 10.1006/frne.1996.0001
Alexander SL, Irvine CH, Donald RA.Since 1985, we have applied our nonsurgical technique for collecting pituitary venous (PitVen) blood from ambulatory horses to investigate the regulation of adrenocorticotropic hormone (ACTH) secretion. This method offers particular advantages for studying the hypothalamo-pituitary-adrenal axis since its benign nature enables hypothalamic and pituitary interactions to be monitored without disturbing the animal, and the horse's large blood volume allows 3- to 4-ml samples to be collected as frequently as every 20s for prolonged periods so that the secretion patterns of ACTH and its secretagogue...
Neutron anatomy.
Basic life sciences    January 1, 1996   Volume 64 17-27 doi: 10.1007/978-1-4615-5847-7_2
Bacon GE.The familiar extremes of crystalline material are single-crystals and random powders. In between these two extremes are polycrystalline aggregates, not randomly arranged but possessing some preferred orientation and this is the form taken by constructional materials, be they steel girders or the bones of a human or animal skeleton. The details of the preferred orientation determine the ability of the material to withstand stress in any direction. In the case of bone the crucial factor is the orientation of the c-axes of the mineral content-the crystals of the hexagonal hydroxyapatite- and this...
Metabolic, hormonal, and hemodynamic changes during dopamine infusions in halothane anesthetized horses.
Veterinary surgery : VS    January 1, 1996   Volume 25, Issue 1 88-97 doi: 10.1111/j.1532-950x.1996.tb01383.x
Robertson SA, Malark JA, Steele CJ, Chen CL.Selected metabolites, hormones and cardiovascular variables were measured in halothane anesthetized horses during 1 hour of dopamine infusion at a rate of 5 micrograms/kg/min (low) and 10 micrograms/kg/min (high), and for 1 hour after infusion. Plasma cortisol increased twofold in the low-infusion group but did not change significantly in the high-infusion group. Plasma nonesterified fatty acids, blood glucose, blood lactate, and plasma insulin increased in the high-infusion group. There was little difference in heart rate, systolic, diastolic, and mean arterial blood pressure between the two ...
Haematological and biochemical changes in horses competing in a 3 Star horse trial and 3-day-event.
Equine veterinary journal. Supplement    November 1, 1995   Issue 20 57-63 doi: 10.1111/j.2042-3306.1995.tb05009.x
Andrews FM, Geiser DR, White SL, Williamson LH, Maykuth PL, Green EM.Haematological and biochemical changes in horses competing in the Endurance Test (Phase T and D) of an advanced Horse Trial (HT, n = 22) and the Endurance Test (Phases A-D) of an advanced (CCI) 3-day-event (TD, n = 11) over a similar course on the same day were studied. Environmental conditions during the event were cool (5.5-11.1 degrees C). Blood samples were collected from the horses in each group the evening prior to the Endurance Test, within 60 s after, and 10 min after, completion of Phase D (cross-country jumping). The following were determined in the blood samples and compared between...
Preweaning diet and stall weaning method influences on stress response in foals.
Journal of animal science    October 1, 1995   Volume 73, Issue 10 2922-2930 doi: 10.2527/1995.73102922x
Hoffman RM, Kronfeld DS, Holland JL, Greiwe-Crandell KM.The stress response of foals during weaning was examined in terms of a behavioral protocol and the responses of plasma ascorbate, serum cortisol, and the serum cortisol response to an ACTH challenge. The experimental plan was a 2 x 2 factorial of two preweaning diets and two stall weaning methods. Dietary groups included foals raised on pasture supplemented with hay and a pelleted concentrate (PHC) and foals raised on pasture supplemented with hay only (PH). Stall weaning methods included foals placed in stalls singly or in pairs. Sex influences were also examined. The foals exhibited characte...
Quantitative electroencephalographic evaluation to determine the quality of analgesia during anesthesia of horses for arthroscopic surgery.
American journal of veterinary research    March 1, 1995   Volume 56, Issue 3 374-379 
Miller SM, Short CE, Ekström PM.We compared the anesthetic combination of detomidine, ketamine, and halothane in control horses not undergoing apparently painful procedures with that in horses during arthroscopic surgery. The effectiveness of this regimen in suppressing neurologic response to surgery was, thus, evaluated. In this study, significant differences were not observed in electroencephalographic total amplitude, spectral edge, or beta-to-delta frequency ratio between surgically treated and nonsurgically treated (control) horses. On the basis of its attenuation of encephalographic responses, we conclude that detomidi...
Stress protection afforded by a cast on plate fixation of the distal forelimb in the horse in vitro.
Veterinary surgery : VS    January 1, 1995   Volume 24, Issue 1 49-54 doi: 10.1111/j.1532-950x.1995.tb01292.x
Parente EJ, Nunamaker DM.Six forelimb specimens from three adult horses had the fetlock joint fused by application of a dorsal plate and by a screw placed in lag fashion through the metacarpus to each proximal sesamoid bone. Five specimens were instrumented on the central dorsal surface of the plate with a single rosette strain gage, and the plate of the sixth specimen was instrumented with four longitudinally oriented single-axis strain gages. The specimens were loaded axially in compression to 4,000 N in a cast (test 1), in a cast with a heel block (test 2), and uncast (test 3). The principal angle of strain in all ...
Effect of food deprivation on baseline iodothyronine and cortisol concentrations in healthy, adult horses.
American journal of veterinary research    January 1, 1995   Volume 56, Issue 1 116-121 
Messer NT, Johnson PJ, Refsal KR, Nachreiner RF, Ganjam VK, Krause GF.Six healthy, adult horses, with normal (mean +/- SEM) baseline serum concentrations of total triiodothyronine (T3, 1.02 +/- 0.16 nmol/L), free T3 (FT3, 2.05 +/- 0.33 pmol/L), total thyroxine (T4, 19.87 +/- 1.74 nmol/L), free T4 (FT4, 11.55 +/- 0.70 pmol/L), total reverse T3 (rT3, 0.68 +/- 0.06 nmol/L), and cortisol (152.75 +/- 17.50 nmol/L), were judged to be euthyroid on the basis of response to a standardized thyroid-stimulating hormone response test. Serum concentrations of T3, FT3, T4, FT4, rT3, and cortisol were determined immediately before and every 24 hours during a 4-day period of foo...
1 27 28 29 30 31 34