bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elemental composition of muscle at rest and potassium levels in muscle, plasma and sweat of horses exercising at 20°C and 35°C
Authors: GOTTLIEB‐VEDI M. , DAHLBORN K. , JANSSON A. , WROBLEWSKI R. 
Published: June 2010

SummaryIn this study, 4 Standardbred geldings were exercised at 20 and 35°C. The exercise test (ET) consisted of 2 exercise bouts separated by 2 h of rest in their boxes. Blood samples were taken before, during and after the second exercise bout and muscle (m. gluteus medius) biopsies were taken before the first exercise bout and after an intensive trot over 2600 m in the second exercise bout. The blood samples were analysed for plasma potassium and total plasma protein concentration (TPP) and the muscle fibres were analysed for elemental composition by x‐ray microanalysis. The intracellular content was as follows: sodium (Na) = 40 ± 7; magnesium (Mg) = 32 ± 4; phosphorus (P) = 282 ± 15; sulphur (S) = 222 ± 13; chloride (Cl) = 119 ± 31; potassium (K) = 304 ± 21 and calcium (Ca) = 8 ± 2 mmol/kg dry weight under resting conditions. Intracellular potassium content increased after exercise compared to resting values. There was a good correlation between exercise intensity, plasma potassium concentration and shifts in plasma volume, indicated by alterations in TPP. This probably reflects the very fast shift of potassium and fluid between muscle and plasma. Plasma potassium concentrations decreased below resting values post exercise. The higher dehydration degree and potassium sweat loss after exercise at 35°C was not reflected in lower muscular potassium content, but by a lower plasma potassium/total plasma protein ratio after exercise, indicating less circulating potassium.
Acid‐base and electrolyte effects of shortening steeplechase in a Three‐day‐event
Authors: FOREMAN J. H. , GRUBB T. L. , BENSON G. J. , FREY L. P. , FOGLIA R. A. , GRIFFIN R. L. 
Published: June 2010

SummaryThis study was designed to characterise the acid‐base and electrolyte effects of shortening the distance required during steeplechase (Phase B) in the face of hot and humid weather conditions during a treadmill‐simulated Speed and Endurance test.Eight conditioned Thoroughbred horses underwent 3 randomised permutations of a standardised exercise test on a high speed treadmill. Each test consisted of trotting at 3.7 m/s for 10 min (Phase A); galloping at 11 m/s (Phase B) for 4 (cool laboratory conditions), 3 (hot and humid), or 2 (hot and humid) min; trotting at 3.7 m/s for 30 min (Phase C); and walking at 1.8 m/s for 10 min (Phase X). The treadmill slope was 4% for trotting and galloping and 0% for walking. Cool versus hot and humid conditions were 20°C and 50–60% relative humidity vs. 26–28°C and 80–85% relative humidity, respectively.Pulmonary artery blood samples were obtained at rest prior to exercise (Rest); at the end ofPhases A(A10) andB(B2‐4); at 10 (C10), 20 (C20) and 30 (C30) min throughPhase C; and at 5 min intoPhase X(X5). Additional samples for lactate (LA) and glucose (GLC) analysis were obtained 5 min intoPhase C(C5) and at the end ofPhase X(X10). Samples were analysed for packed cell volume (PCV), haemoglobin (HB), total plasma protein (TP), sodium (Na), potassium (K), chloride (Cl), anion gap (AG), plasma glucose (GLC) and lactate (LA), pH, PCO2, bicarbonate (HCO3) and base excess (BE).Shortening steeplechase distance by 50% under hot and humid conditions (2 min B) resulted in a consistent return to control measurements (4 min B) only for plasma LA. Changes in PCV, HB, TP, K and Cl were related more to the longer galloping distance in the 4 min B trials than to hot vs. cold laboratory conditions. Alternatively, changes in LA, GLC, pH, PCO2and AG were more related to hot and humid laboratory conditions than they were to galloping distance. These latter variables, when combined with physical measures such as core temperature, bodyweight loss, point of fatigue onPhase Cand recovery heart rates may serve as the best monitors of positive responses in future studies of proposed modifications toPhase C, rather than those variables which were more distance than weather‐related.
Ground reaction forces in horses, assessed from hoof wall deformation using artificial neural networks
Authors: SAVELBERG H. H. C. M. , VAN LOON T. , SCHAMHARDT H. C. 
Published: June 2010

SummaryAn artificial neural network (ANN) was developed to investigate whether hoof wall deformation could be used to determine ground reaction forces (GRF) in horses. The ANN was taught this relationship under certain conditions and was able to generalise this knowledge to conditions for which it was not trained before.To acquire data to train and test the ANN, a horse was equipped with strain gauges attached to the dorsal, lateral and medial parts of the hoof to assess hoof wall deformation. A force plate was used to measure the GRFs. Both hoof wall deformation and GRF were recorded simultaneously at different speeds, gaits, surfaces and loads. An ANN was trained with some of these data, and subsequently provided with strain gauge recordings of strides, not used for training. By comparing the GRF calculated by the ANN based on the hoof wall deformation with that recorded simultaneously by the force plate, the generalisability of the ANN was determined. It was found that an ANN is capable of ‘learning’ the relationship between hoof wall deformation and GRF, and to generalise it to a wide range of new conditions. This technique enables assessment of GRF under difficult conditions, such as on a treadmill or on surfaces where a force plate cannot be employed.
Radiological assessment of the effects of a full rolling motion shoe during asymmetrical bearing
Authors: CAUDRON I. , MIESEN M. , GRULKE S. , VANSCHEPDAEL P. , LEROY P. , SERTEYN D. 
Published: June 2010

SummaryThe authors used a new radiological method to assess asymmetrical articular compression of the interphalangeal joints. This method was based on the measurements of 3 angles obtained on dorsopalmar radiographs. Variations of these angles were studied during experimental asymmetrical bearing on unshod feet. It was concluded that 2 angles were interesting parameters to assess asymmetrical articular compression and to define the position of the phalanx in the horny box. Furthermore, variations of these angles induced by experimental asymmetrical bearing were compared without shoe, with a standard shoe and with an orthopaedic full rolling motion shoe. It was observed that the effects of the asymmetrical bearing were reduced when feet were shod with a full rolling motion shoe.
Model for injury to the foreleg of the Thoroughbred racehorse
Authors: PRATT G. W. 
Published: June 2010

SummaryA discussion is presented of contributing factors to the injury to the foreleg of the Thoroughbred racehorse. The critical part of the step is taken to be the first 10–20 ms after ground contact as the hoof slides forward and stops. Large nonaxial loads associated with the deceleration of the hoof are shown to arise. Results of accelerometer measurements on the hoof of a horse running at racing speed are presented as well as mechanical properties of the racing surface. The mechanical properties of the track surface, the type of shoe, and the degree of fatigue of the horse all work together to determine the level of risk.
Joint moments and power in equine gait: a preliminary study
Authors: COLBORNE G. R. , LANOVAZ J. L. , SPRIGINGS E. J. , SCHAMHARDT H. C. , CLAYTON HILARY M. 
Published: June 2010

SummaryA method is described for the estimation of joint moments of force and power in the equine forelimb using S‐VHS video and force platform data. Video and force data were collected for 5 walking trials in a sound Dutch Warmblood horse. The sagittal plane positional and angular data were combined with the vertical and cranio‐caudal ground reaction forces to calculate net joint moments of force in the sagittal plane across the carpal, fetlock and coffin joints during the stance phase of the forelimb. The mechanical power was calculated as the product of the net joint moment and the joint's angular velocity. The carpus demonstrated oscillating periods of energy generation and absorption in early stance against a flexor moment, then an absorption phase at the end of stance as the carpus flexed against an extensor moment. The fetlock absorbed energy in early stance as it flexed against an extensor moment, then showed short periods of positive and negative work in mid‐stance. Energy was generated across the fetlock as it extended for push‐off. An extensor moment was measured at the coffin joint through most of stance, and this coincided with a phase of energy absorption followed by a longer phase of generation. In terminal stance, a flexor moment was produced and this was accompanied by a period of generation for push‐off.
Power flow in the equine forelimb
Authors: COLBORNE G. R. , LANOVAZ J. L. , SPRIGINGS E. J. , SCHAMHARDT H. C. , CLAYTON HILARY M. 
Published: June 2010

SummaryA method is described for the estimation of segmental powers and power flow during the stance phase in the equine forelimb, to demonstrate the sources and paths of energy flow through the limb segments. S‐VHS video and force platform data were collected for 5 walking trials in a sound Dutch Warmblood horse. Two camera views were combined using direct linear transformation and the resultant sagittal plane positional and angular data used together with the vertical and cranio‐caudal ground reaction forces to calculate moments about the ends of the 4 lowermost segments of the forelimb, and the reaction forces at the segment ends. Power flows were calculated across the proximal and distal ends of each segment and total segmental power computed. During initial and terminal stance, power flowed into the cannon segment proximally, and out distally. For the rest of stance, the flow in the cannon was distal to proximal. At the pastern, power flowed in proximally during initial loading, and out distally. For most of the rest of stance, the pattern of flow was distal to proximal, except for terminal stance, when power flowed in through both ends. The largest effect at the hoof is a loss of energy in terminal stance as power flowed out proximally and into the pastern. The pastern appears to receive most of the energy during loading and pushoff and transfers this energy up the limb during midstance.
Effect of added weight on landing kinematics in jumping horses
Authors: CLAYTON HILARY M. 
Published: June 2010

SummarySix event horses jumped a 1.10 m high table fence 4 times under each of 2 conditions; the rider weight condition involved carrying the weight of the rider and saddle (61 kg), whereas the added weight condition included an additional 18 kg weight cloth. Sagittal view, 60 Hz video recordings were analysed using standard methods. Comparisons between the rider weight and added weight conditions using pairedttests (P<0.05) showed a number of significant differences. In the added weight condition the leading forelimb landed closer to the fence, and there were increases in the maximal extension of the fetlock and carpal joints in this limb during the landing phase. In the first departure stride, the stance durations of both hindlimbs increased, and the advanced placement between them was reduced for the added weight condition. The head was significantly further ahead of the vertical in the added weight condition at the instants of ground contact of the TrH, LdH and TrF in the first departure stride.
Effects of trot quality and collection on the angular velocity in the hindlimbs of riding horses
Authors: HOLMSTRÖM M. , DREVEMO S. 
Published: June 2010

SummaryThe angular velocities of the hindlimb angles of 14 horses, including 6 Grand Prix dressage horses, 4 horses judged as good at the trot and 4 horses judged as poor, were analysed. The horse material was the same as previously used by Holmström (1994) in studies on conformation and trotting gaits in the Swedish Warmblood riding horse. Four consecutive strides of each horse and the corresponding pace were analysed and mean velocity curves (Xh) for each angle were calculated. Before calculation the data were filtered forwards and backwards with a Butterworth third order filter with a cut off frequency of 60 Hz. During the last 60% of the stance phase there were differences between the horses judged as good and poor at the trot in all the analysed hindlimb angles except the femur inclination. The angular velocity in the hock joint, pelvis inclination and hindlimb pendulation was larger in the good horses. The angular velocity of the hindlimb pendulation decreased with collection in the Grand Prix horses. During parts of the stance phase, there was also a gradual decrease in the femur angular velocity from trot at hand to piaffe. In the hock joint, there was no difference in angular velocity between trot at hand and passage during the last 30%. The higher compression of the hock angle and pelvic angle to the horizontal plane probably reflects a higher compression of the whole hindlimb. It probably contributes to the greater springiness in the movements of good young horses and Grand Prix dressage horses. The results from the present study confirmed the importance of storing elastic strain energy for the quality of the dressage horse gaits.
Effects of treadmill inclination on kinematics of the trot in Dutch Warmblood horses
Authors: VAN OLDRUITENBORGH‐OOSTERBAAN MARIANNE M. SLOET , BARNEVELD A. , SCHAMHARDT H. C. 
Published: June 2010

SummaryTo evaluate the effects of uphill trotting on stride characteristics, 6 well trained Dutch Warmblood horses trotted at 4 m/s on a horizontal and on an inclined (6%) treadmill. This was done under 3 different conditions, unloaded, mounted by an experienced 90 kg rider and loaded with 90 kg of lead, to study whether extra weight provoked more or different alterations than the incline per se. In all 3 test situations (unloaded, mounted and lead‐loaded), heart rates were significantly higher on the inclined treadmill than on the horizontal treadmill. Stride duration tended to increase on the inclined treadmill. Stance duration increased significantly on a slope, more in the hindlimbs than in the forelimbs. In the unloaded condition, maximal fetlock extension of the forelimb decreased on the incline, whereas maximal fetlock extension of the hindlimb and tarsal range of motion increased significantly on the slope in all 3 conditions.The overall effect was that on an inclined treadmill the hindlimbs seemed to carry more weight (higher maximal fetlock extension), and to provide greater propulsion (higher tarsal flexion and increased pro/retraction).
Kinematics and kinetics of the carpus
Authors: JOHNSTON C. , DREVEMO S. , ROEPSTORFF L. 
Published: June 2010

SummaryThis study investigated the kinematics and kinetics of the carpus during the stance phase. Five Standardbred horses trotted on a treadmill at 8.9 m/s. The kinematics of the horses were filmed and hoof reaction forces (HRF) were recorded. The carpus was overextended throughout most of the stance. There were 2 periods of overextension, a more rapid period in the beginning of the stance and second directly following the first period. Maximal overextension occurred slightly before the second minimum of the braking horizontal HRF. The metacarpal and antebrachial segments rotated counterclockwise for most of the stance. The angular velocities of these segments attained absolute and local extremes that were concurrent. The absolute maxima in the longitudinal and the transversal acceleration of the proximal metacarpus were coincident in time with the minimal horizontal braking force. The moment of force about the carpus was extending throughout most of the stance, with a short period of flexion near the end of the stance. The results show that horizontal braking of the hoof results in impulsive loading followed by maximal overextension of the carpus. The second phase of overextension is suggested to be related to the tension or active roll of the flexor tendons of the distal limb. The carpus is, therefore, subjected to rapid and high loading in both the longitudinal and transversal directions, as well as large moments and forces.
Investigating locomotion of dairy cows by use of high speed cinematography
Authors: HERLIN A. H. , DREVEMO S. 
Published: June 2010

SummaryThe longterm influence of management systems on the locomotion of 17 dairy cows was investigated by high speed cinematography (100 frames/s) and kinematic analysis. Angular patterns and hoof trajectories of the left fore‐ and hindlimbs are presented and statistics made of occurring minimum and maximum angles. At the recording, 3 cows had been kept in tie‐stalls (TI) and 6 cows in cubicles (CI) for a consecutive time of about 2.5 years while 8 cows had been kept on grass for about 3 months. Four of the grazing cows had earlier been kept in cubicles (CG) and 4 in tie‐stalls (TG) during earlier off grazing seasons together with TI and CI cows. The CI cows had a smaller maximum angle of the elbow joint compared to TI, TG and CG cows. The hock joint angle of the CI cows was less flexed during the stance phase than in TI and CG cows while the minimum angle during the swing phase was greater in the TI and CI cows compared to TG and CG cows. Pastured cows (TG and CG) had a less pronounced flexion of the fetlock joint angle during the stance compared to cows kept indoors (TI and CI). The results suggest that slatted floor and lack of exercise during summer grazing may affect locomotion. This is indicated by restrictions in the movements of the elbow and hock joints and in less fetlock joint flexion at full support.
Aspects of autonomic and neuroendocrine function
Authors: EDWARDS A. V. 
Published: June 2010

SummaryThis article provides a brief review of aspects of autonomic and neuroendocrine function studied initially in collaboration with the late Marian Silver. The importance of the sympathetic innervation to the liver in the control of glycogenosis was established in anaesthetised animals of various species. Otherwise the work has been carried out mainly in conscious animals under strictly physiological conditions and below behavioural threshold.Investigations of the role of the autonomic innervation to the endocrine pancreas in controlling the release of pancreatic hormones, led to the realisation that the parasympathetic innervation mediates reponses to glycaemic stimuli while the sympathetic innervation mediates responses to any form of stress. Studies of adrenal medullary function have confirmed that its threshold for many forms of stress is much higher than that of other components of the sympathetic system and revealed the importance of the pattern of electrical stimulation in determining the rates of release of catecholamines, enkephalins, corticotrophin‐releasing factor (CRF) and adrendocorticotrophin (ACTH). The splanchnic sympathetic innervation to the adrenal cortex also plays an important role in determining glucocorticoid output by sensitising the cells to ACTH, probably mainly by the release of vasoactive intestinal peptide (VIP) from cortical nerve terminals. Finally studies of feeding in milk‐fed calves have shown that suckling is associated with a remarkable hypertension and tachycardia. These cardiovascular effects are due to a selective sympathetic discharge, which does not involve the adrenal medullae, or the release of neuropeptide Y (NPY) and, at least in the calf, can be attributed to activation of adrenoceptors.
Follicular fluid is not a compulsory carrier of the oocyte at ovulation in the mare
Authors: PALMER E. , DUCHAMP G. , CRIBIU E.P. , MAHLA R. , BOYAZOGLU SONIA , BÉZARD JACQUELINE 
Published: June 2010

SummaryThe aim of this study was to test the possibility that ovulation can occur from a preovulatory follicle emptied of its follicular fluid. Transport of the oocyte into the oviduct and fertilisation in 29% of cases demonstrated that ovulation can occur in the absence of follicular fluid but the higher fertility achieved in control mares (62.5%) suggested that follicular fluid does serve a role during ovulation, fertilisation and oviductal transport. Injection of horse oocytes into preovulatory follicles in mules after removal of the follicular fluid, followed by insemination of the mules with horse semen, resulted in the production of one horse x horse embryo.
Equine oocyte‐cumulus morphology as affected by follicular size
Authors: MLODAWSKA W. , OKÓLSKI A. 
Published: June 2010

SummaryFrom the ovaries of 256 slaughtered mares a total of 1713 follicles were isolated from which 1641 (95.8%) oocytes were recovered (6.4/mare). A total of 564 follicles and oocytes were evaluated for the degree of vascularisation of the follicle wall, the appearance of the follicular fluid and the location and morphology of the cumulus‐oocyte‐complex. Follicles with a diameter of >10 mm displayed more numerous, well branched and more pronounced blood vessels than the smaller ones (4–10 mm diameter) and most of them contained clear, yellowish fluid with few granulosa cells. The percentage of oocytes with compact cumuli increased significantly with an increasing diameter of the follicle, being 233%, 43.9%, 55.6% and 64.2% (P < 0.01) for the follicles with diameters of 4–10, 11–15, 16–20 and 21–35 mm, respectively. The percentage of oocytes attached to the follicle wall also increased with increasing follicle size, being 48.0%, 59.6%, 81.5% and 90.1% (P < 0.01), respectively. On the contrary, the percentage of oocytes floating in the follicular fluid decreased with increasing follicle diameter, from 52.0% in the smallest follicles to 9.9% in the biggest ones. A significantly greater percentage of oocytes found on the follicular wall than in the follicular fluid had a compact cumulus (56.6 versus 213%; P < 0.01). Forin vitroculture were accepted 30.4%, 54.3%, 60.7% and 77.8% (P < 0.01) of oocytes from the follicles with diameters of 4–10, 11–15, 16–20 and 21–35 mm, respectively. After culture for 28–40 h in TCM 199 medium, 90 of a total of 165 (54.5%) oocytes reached the metaphase II stage of maturation.
Treatment of equine oocytes with A23187 after intracytoplasmic sperm injection
Authors: KATO H. , SEIDEL G. E. , SQUIRES E. L. , WILSON J. M. 
Published: June 2010

SummaryIn vitro matured horse oocytes with a first polar body (n = 68) were each injected with a single spermatozoon and divided into 2 groups: Group 1 oocytes were treated with 10 μM calcium ionophore A23187 for 5 min while Group 2 oocytes received no activation treatment. After culture in vitro for 2 days, significantly more oocytes treated with A23187 (5/24, 21%) cleaved than oocytes without activation treatment (2/44, 5%, P < 0.05). All 7 cleaved zygotes from both treatment groups were transferred to recipient mares but no pregnancies resulted.
Spontaneous multiple ovulation and development of multiple embryonic vesicles in a mare
Authors: BRÜCK INGRID , LEHN‐JENSEN H. , YDE G. 
Published: June 2010

SummaryA Warmblood mare was observed to ovulate spontaneously 12 follicles within 2 days, none of which exceeded 22 mm in diameter. On Days 13 and 17 after ovulation, 6 embryonic vesicles were identified in the uterus by ultrasonography but by Day 26, 5 of the vesicles had disappeared. Development of the surviving conceptus was monitored until Day 42. Plasma progesterone concentrations rose to 14 ng/ml on Day 7, decreased over the next 8 days and then plateaued to around 4–6 ng/ml until Day 70. The occurrence of multiple spontaneous ovulations was diagnosed repeatedly in this mare. However, the developmental competence of the ovulated oocytes seemed to be impaired.