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1.
OBJECTIVE: To quantify variation in the jumping technique within and among young horses with little jumping experience, establish relationships between kinetic and kinematic variables, and identify a limited set of variables characteristic for detecting differences in jumping performance among horses. ANIMALS: Fifteen 4-year-old Dutch Warmblood horses. PROCEDURE: The horses were raised under standardized conditions and trained in accordance with a fixed protocol for a short period. Subsequently, horses were analyzed kinematically during free jumping over a fence with a height of 1.05 m. RESULTS: Within-horse variation in all variables that quantified jumping technique was smaller than variation among horses. However, some horses had less variation than others. Height of the center of gravity (CG) at the apex of the jump ranged from 1.80 to 2.01 m among horses; this variation could be explained by the variation in vertical velocity of the CG at takeoff (r, 0.78). Horses that had higher vertical velocity at takeoff left the ground and landed again farther from the fence, had shorter push-off phases for the forelimbs and hind limbs, and generated greater vertical acceleration of the CG primarily during the hind limb push-off. However, all horses cleared the fence successfully, independent of jumping technique. CONCLUSIONS AND CLINICAL RELEVANCE: Each horse had its own jumping technique. Differences among techniques were characterized by variations in the vertical velocity of the CG at takeoff. It must be determined whether jumping performance later in life can be predicted from observing free jumps of young horses.  相似文献   

2.
The purpose of this study was to quantify performance characteristics of good jumping horses, and to determine whether these were already detectable at foal age. Kinematic data were collected of horses performing free jumps over a 0.60 m high fence at six months of age and of these same horses jumping with a rider over a 1.15 m high fence at five years of age. At five years of age the horses were divided into three groups on the basis of a puissance competition: a group of seven best jumpers that made no errors and in the end cleared a 1.50 m high fence, a group of nine worst jumpers that were unable to clear a 1.40 m high fence, and an intermediate group of 13 horses. Longitudinal kinematic data was available for all seven best jumpers and for six of the nine worst jumpers. Average values of variables for the best jumpers were compared with those of the worst jumpers for the jumps over 1.15 m. In the group of best jumpers, the forelimbs were shorter at forelimb clearance due to increased elbow flexion, and the hind limbs were further retroflexed at hind limb clearance. The same superior technique in clearing fences with the limbs was also found in this group at six months of age. Nevertheless, for individual horses it turned out to be too far-fetched to predict adult jumping capacity on the basis of kinematic variables collected during submaximal jumps at foal age.  相似文献   

3.
OBJECTIVE: To determine whether differences in jumping technique among horses are consistent at various ages. ANIMALS: 12 Dutch Warmblood horses. PROCEDURE: Kinematics were recorded during free jumps of horses when they were 6 months old (ie, no jumping experience) and 4 years old (ie, the horses had started their training period to become show jumpers). Mean +/- SD height of the horses was 1.40 +/- 0.04 m at 6 months of age and 1.70 +/- 0.05 m at 4 years of age. RESULTS: Strong correlations were found between values from 6-month-old foals and 4-year-old horses for variables such as peak vertical acceleration generated by the hind limbs (r, 0.91), peak rate of change of effective energy generated by the hind limbs (r, 0.71), vertical velocity at takeoff (r, 0.65), vertical displacement of the center of gravity during the airborne phase (r, 0.81), and duration of the airborne phase (r, 0.70). CONCLUSIONS AND CLINICAL RELEVANCE: Although there are substantial anatomic and behavioral changes during the growing period, certain characteristics of jumping technique observed in na?ve 4-year-olds are already detectable when those horses are foals.  相似文献   

4.
OBJECTIVE: To investigate whether training for show jumping that is commenced early after birth affects the characteristics of equine locomotory muscle. ANIMALS: 19 Dutch Warmblood horses. PROCEDURES: Horses were assigned to a trained or not trained (control) group. After weaning, training (free jumping [2 d/wk] that was alternated with a 20-minute period of exercise in a mechanical rotating walker [3 d/wk]) was started and continued until horses were 3 years old. Fiber type composition (determined from myosin heavy chain [MyHC] content), fiber area, diffusion index (area supplied by 1 capillary), citrate synthase activity, and Na(+),K(+)-ATPase content were assessed in gluteus medius muscle specimens collected at 0.5, 1, 2, and 3 years. RESULTS: Developmental changes included an increase in MyHC fiber type IIa and a decrease in type IIad; increases in fiber area, diffusion index, and citrate synthase activity; and a decrease in Na(+),K(+)-ATPase content. The MyHC fiber type I and type IId were detected in high and low proportions, respectively. Training increased Na(+),K(+)-ATPase content, but did not affect other variables. CONCLUSIONS AND CLINICAL RELEVANCE: In horses, show jumping training at an early age resulted in increased Na(+),K(+)-ATPase content of the deep portions of the gluteus medius muscle. The lack of training effects on the other muscle characteristics can partly be explained by the fact that an appropriate (aerobic) fiber type composition was already established at training commencement. These data also suggested that the developmental changes in equine muscle represent sufficient adaptation to meet the demands of this specific training.  相似文献   

5.
REASONS FOR PERFORMING STUDY: The costs and investments required for the purchase and training of showjumpers justify the need to find selection means for jumping horses. Use of objective kinematic criteria correlated to jumping ability could be helpful for this assessment. OBJECTIVES: To compare back kinematics between 2 groups of horses of different competition levels (Group 1, competing at high level; Group 2 competing at low level) while free jumping over a 1 m vertical fence. METHODS: Three-dimensional recordings were performed using 2 panning cameras. Kinematic parameters of the withers and tuber sacrale (vertical displacement, vertical and horizontal velocities), backline inclination and flexion-extension motion of the 3 main dorsal segments (thoracic, thoracolumbar and lumbosacral) were analysed. RESULTS: Group 2 horses had a lower displacement of their withers and tuber sacrale from the end of the last approach stride until the first departure stride (P<0.05). As a result, they increased the flexion of their thoracolumbar and lumbosacral junctions during the hindlimb swing phase before take-off (P<0.05). However, withers and tuber sacrale velocities were slightly modified. Group 1 horses pitched their backline less forward during the forelimb stance phase before take-off and straightened it more after landing (P<0.05), probably indicating a more efficient strutting action of their forelimbs. CONCLUSIONS AND POTENTIAL RELEVANCE: Because significant differences in back motion were found between good and poor jumpers when jumping a 1 m high fence, criteria based on certain back kinematics can be developed that may help in the selection of talented showjumpers.  相似文献   

6.
Between 1994 and 2001, guttural pouch tympany was diagnosed in 51 foals; there were approximately three times as many fillies as colts, of Arabian, different German warmblood breeds and Western horse breeds. There were significantly more Arabian and paint horse foals than expected in comparison with the breed distribution of the foals hospitalised at the Clinic for Horses. The foals' breed and sex did not influence the age of onset, the type and severity of the clinical signs or the recurrence rate. A surgical laser technique was used on 50 of the foals; in 35 cases only one surgical treatment was necessary, in seven cases a second operation was required during the foal's initial period of hospitalisation, and in eight cases a second operation was performed during a second period of hospitalisation. Long-term follow-up information was obtained for 44 of the 50 treated horses; 24 of them were under two years of age and 20 were over two years of age. In six horses, no follow-up information was available. Four horses were euthanased for reasons unrelated to the condition or its treatment. The horses over two years of age were in training or were being used for competitions in dressage or jumping or for breeding purposes, and in only one of them was an adventitious respiratory noise reported. All the horses up to two years of age were reported to be healthy.  相似文献   

7.
A matched case-control study was made of 100 thoroughbred horses which were coughing and 148 control horses which were free of clinical signs of respiratory tract disease. The variables identified by multivariable conditional logistic regression as being significantly associated with coughing included age (the risk decreased with age), the stage of training (horses in early training were at greatest risk), the time since the last race (horses that had never raced were at greatest risk) and the time since they were last transported (horses transported more than 14 days previously were more likely to cough than those transported within the last week). The coughing horses were significantly more likely to have high scores for upper and lower tracheal mucus and pharyngeal lymphoid hyperplasia. In addition, the tracheal aspirates of the coughing horses had increased odds of neutrophilia and were more likely to have intracellular bacteria than the control horses. However, a considerable proportion of the control horses had cytological and/or endoscopic evidence of airway inflammation.  相似文献   

8.
The aim of this study was to compare the effect of exercise on nitric oxide (NO), carbon monoxide (CO), and cyclic guanosyl monophosphate (cGMP) levels in jumping and dressage horses involved in competition. Blood samples were collected from the jugular vein of 100 horses involved in jumping or dressage competition at three time points: baseline at rest, on reaching the schooling but before exercise, and over a jump or dressage course. Fourteen healthy horses not involved in competition were used as control group. Exercise increased plasma CO concentration in both jumping and dressage horses, and this effect was more apparent in dressage horses. Exercise also increased NO plasma concentration in jumping horses, whereas it did not significantly modify NO plasma concentration in dressage horses. After exercise, plasma cGMP concentration was higher in both groups. Our results show that different signaling pathways are initially activated by exercise and that this activation is specific to the different modes of exercise. This information can be used to optimize warm-up and cool-down procedures for sport horses or to optimize training programs for equine athletes.  相似文献   

9.
Muscle biopsies were taken from the middle gluteal muscle of 28 Standardbred trotters, 3-4 years of age. The 13 horses in Group T were trained consistently from 18 months of age, whereas the 15 horses in Group UT were not exposed to any systematic training before 3 years of age. Group T horses had a lower percentage of Type IIB fibres (31%) than did Group UT horses (39%). Citrate synthase (CS) activity, representing oxidative capacity, was higher in Group T (72 mmol kg-1 min-1) than in Group UT (47 mmol kg-1 min-1). Biopsies were taken from 4 horses in each group when they were foals and then annually until 3-4 years of age. Results from this study indicate that regular training of Standardbreds from 18 months of age resulted in increased CS activity and a decrease in the percentage of Type IIB fibres. This study shows that training, not growth, is the main factor that induces a high oxidative capacity and a high Type IIA/IIB fibre ratio in muscle of Standardbred trotters.  相似文献   

10.
REASONS FOR PERFORMING STUDY: Early diagnosis and monitoring progression of chronic diseases in elastin-rich tissues, such as chronic progressive lymphoedema in draught horses and chronic obstructive pulmonary disease (COPD) is still a real challenge in the horse. Use of an enzyme-linked immunosorbent assay (ELISA) to detect anti-elastin antibody (AEAb) levels might be useful to assess the status of such diseases. Baseline levels, representing physiological breakdown of elastin in normal horses, are not available at present. HYPOTHESIS: Levels of AEAb in healthy horses are generally low and follow the same age-related pattern as found in man. Therefore, elevation of AEAb levels in serum can be used to evaluate pathological elastin breakdown in elastin-rich tissues. METHODS: Sera of 84 clinically healthy Warmblood horses were evaluated for the presence of AEAbs by means of a modified version of an ELISA technique used in man. The horses were divided in 5 age groups: A) < 4 months; B) 4-23 months; C) 2-3 years; D) 4-10 years; and E) > 11 years. RESULTS: Antibodies to elastin were found in all equine serum samples tested. Their levels were lowest in Group A, low in Groups B and E and highest in animals age 2-10 years. CONCLUSIONS: Measuring AEAbs in serum of horses by an ELISA technique proved to be possible and levels were stable during well-defined life stages. POTENTIAL RELEVANCE: Changes in AEAb levels are expected to be useful for early diagnosis and for monitoring progression of diseases that affect elastin-rich tissues, such as chronic progressive lymphoedema and COPD.  相似文献   

11.
The longevity of sport horses is an economic and ethical issue. The aim of this study was to analyze the duration of the competitive life of jumping horses in France to assess the potential for genetic evaluation and to propose rules of management for sport horses. Data included lifetimes spent in jumping competitions for the 209,296 horses born from 1968 onward with performances between 1972 and 2008; the data set contained 22% right-censored records. Longevity was measured in years. Discrete survival analysis included fixed effects of region of birth, month of birth, year of recording, age at first competition, interaction between sex and level of jumping performance as measured by the logarithm of earnings adjusted for sex, age, year, and random sire and maternal grand-sire effects. There were 16,668 sires and maternal grand-sires. All fixed effects were highly significant (P < 0.001). Management of the sports career had an important effect on longevity: against common belief, the younger the horse started competing, the longer it stayed in competition. For horses that started competing at an age of 6 yr, the risk of culling was 1.33-fold that of horses having started at 4 yr of age. The less success in competition, the greater was the chance for leaving competition, especially for horses without earnings. For a gelding without earnings, the risk of culling was 1.40-fold that of an average-performance gelding and 2.57-fold that of a top-rated gelding (performance at least 2 SD above the mean). Mares always had greater relative risk than geldings or stallions because they may be culled from competition to be used for breeding. The risk of culling for females was 1.45-fold that of a gelding with the same performance. The heritability of the length of competitive life was 0.10. Breeding values were predicted for sires, and 3,303 sires showed an accuracy greater than 0.60. Among these sires, 262 were used for breeding in 2008.  相似文献   

12.
Ten trotting Standardbred colts were recorded by high-speed cinematography at the ages of eight, 12 and 18 months. The horses were trotting on a treadmill operating at 4.0 m/secs. Five horses were subjected to a programme of intensified training from eight months of age, whereas the others were not trained and acted as controls. The films were analysed on a semi-automatic film-reading equipment and a number of variables used to demonstrate the gait symmetry were calculated and scaled by computer. Certain differences between left and right diagonal and contralateral pair of limbs, respectively, were noted, suggesting that laterality in horses may be inherited. The most pronounced systematic differences were found in 18-month old horses in the trained group. The results show the importance of careful gait examination and comprehensive coordination training at an early age.  相似文献   

13.
This paper presents the results of arthroscopic surgery in 42 Standardbred trotters and three Finnish horses. Forty-five horses were operated on. The age range was one to seven years; 73 per cent of the horses were three years old or younger. Horses showed a variety of clinical signs ranging from moderate to severe lameness at slow speeds, to obscure lameness manifesting only at high speeds. Synovial effusion of the fetlock joint was rare. In this series, 44 horses that had Type I fragments and one horse that had Type III fragments were operated on. Of the 45 horses operated on, 23 (51 per cent) returned to speed training in three months and 41 (91 per cent) returned to speed training in six months. Three of 45 (6 per cent) were lame three months after the surgery when the trainer attempted to start speed training. One of those was sound six months after the operation. The remaining two (4 per cent) stayed lame due to a lesion in the affected joint. Two of 45 (4 per cent) discontinued training for other reasons. The horse with Type III fragments returned to speed training in three months.  相似文献   

14.
Seven Warmblood horses without sport experience were trained and filmed four times during free jumping, with a 1-month interval between each investigation. Jumping parameters were measured on selected frames by means of video image analysis. Linear and angular parameters describing takeoff, landing, and lifting of limbs above the obstacle were studied. Statistical analysis revealed that the following parameters were affected by training: hind limbs distances at takeoff and landing, lifting of the limbs above the obstacle, and the angle of bascule.  相似文献   

15.
The objective of this study was to determine the incidence of serum neutralising (SN) antibody to ERAV, ERBV1 and ERBV2 in a population of horses from birth to 22 years of age. The prevalences of ERAV, ERBV1 and ERBV2 SN antibodies in 381 sera obtained from 291 horses were 37%, 83% and 66%, respectively. ERAV, ERBV1 and ERBV2 maternal antibody was present in foals 12 h postsuckling but by 10-12 months, ERAV SN antibody was not detected in any of the horses, while ERBV1 and ERBV2 SN antibodies were common (83% and 100%, respectively). Sera were obtained from 44 Thoroughbred horses when they were newly introduced into a training centre when their average age was 23 months and a second sample was obtained approximately 7 months later. ERAV SN antibody was present in 8 (18%) when first bled and in 27 (61%) when tested 7 months later. Accordingly 19 of the 44 horses (43%) seroconverted to ERAV within 7 months of entering the training stable. Among all the horses the average ERAV SN antibody titre was relatively high (3796) and in contrast, ERBV1 and ERBV2 titres were relatively low (average 84 and 45, respectively) and often fell to below detectable levels over time and at a rate comparable to new seroconversions in the same group of horses.  相似文献   

16.
AIM: To examine the growth of spring- and autumn-born Thoroughbred foals raised on pasture. METHODS: Bodyweight and growth rates were measured in pasture-raised Thoroughbred horses, born in either spring (n=56) or autumn (n=7), from birth to approximately 13 and 17 months of age. RESULTS: Birthweight tended to be lower in autumn- than spring-born foals (54.4, SD 7.92 kg vs 57.3, SD 5.90 kg; p=0.08). Between birth and 6 months of age, there was no difference in growth rate at equivalent ages between horses born in spring and autumn. Spring-born horses, which were weaned in the autumn, had lower post-weaning growth rates than autumn-born horses that were weaned in the spring. At time of the late yearling sales (March-April) in the Southern Hemisphere, unadjusted mean bodyweights of autumn-born horses (379.3, SD 24.8 kg) were lower (p=0.017) than those of the spring-born horses (437.2, SD 35.3 kg), although values in the autumn-born horses were all within two standard deviations (SD) of the mean of the spring-born animals. When adjusted for the covariates of birthweight and gender, the difference between spring- and autumn-born horses at that time was not significant (p=0.25). CONCLUSIONS AND CLINICAL RELEVANCE: Some autumn-born foals could be marketed for late yearling sales in the Southern Hemisphere, on the basis of bodyweight. Furthermore, they might also be competitive in the Northern Hemisphere industry (sales or racing), as they would be competing against horses of the same official age.  相似文献   

17.
Reason for performing study: Foot stance in grazing significantly influences hoof conformation and development from foal to yearling age. Objectives: To conduct a longitudinal study to establish if the relationship between motor laterality and uneven front feet persisted in 3‐year‐old horses at the time of studbook selection and to investigate if such laterality and unevenness might influence the horses' ability to perform symmetrically while trotting, cantering and free jumping. Methods: Seventeen clinically sound but untrained (with only minimal experience of handling) and sound Warmblood horses that had participated in a previous study were assessed as per the protocol reported. Laterality was tested in a preference test (PT) and z‐values were calculated for analysis purposes. Laterality and hoof unevenness were related to both relative limb length and relative head size, while the ability to perform symmetrically was tested in free trot‐canter transitions and free jumping exercises. Differences in performance between horses with and without a limb preference in the PT and those with ‘uneven’ and ‘even’ feet were tested for differences in performance metrics using Students' t test, while linearity was tested using a regression analysis (P<0.05). Results: Significant laterality was still present in 24% of the 3‐year‐old horses and the relationship between laterality and uneven feet pairs was stronger than at foal and yearling stages. Horses with significant motor laterality had almost 4 times more unevenness, a smaller head and longer limbs and the relationship between body conformation and laterality was still present. There was a strong linear relation between unevenness, laterality and a bias or side preference for trot‐canter transitions. However, this relationship was not significant during the free jumping exercise. Conclusion: Motor laterality and uneven feet pairs were still present and significantly related in the 3‐year‐old horses and both variables were also strongly related to sidedness in trot‐canter transitions. Potential relevance: Warmblood studbooks should include quantitative data on laterality at the time of studbook admission as part of the selection criteria.  相似文献   

18.
Physiological and hematochemical changes associated with exercise have been extensively investigated in equine species. It is known that stress elevates circulating levels of acute phase proteins (APPs). This survey evaluated whether horses trained with different training programs exhibit changes in APP levels after exercise event. Twenty Saddle Italian horses (11 geldings and 9 females, 9 ± 1 years old, body weight of 425 ± 35 kg) were divided into two equal groups according to the intensity of training programs they were subjected: group A was subjected to an intense training program, group B was subjected to a moderate training program. At the end of the training period, horses were subjected to a simulated exercise event (show jumping course of 400 m length with 12 obstacles). From horses, blood samples were collected at rest conditions (TREST) and after 12 and 24 hour from the end of exercise (T12 h and T24 h); the concentration of serum amyloid A (SAA), haptoglobin, albumin, total proteins, iron, and fibrinogen was assessed. The circulating levels of SAA, fibrinogen, and iron were influenced by simulated exercise event (P < .01), starting from 12 hour after the end of exercise, suggesting the onset of an acute phase–like response, and it would seem that training program intensity the horses underwent also affected the degree of response, although only SAA values were significantly different between groups (P < .001). The findings obtained suggest that jumping exercise induces an acute phase response; however, further studies are advocated to better evaluate mechanisms by which exercise activates this response in the athletic horse.  相似文献   

19.
Cardiac auscultation was carried out on 111 Thoroughbred horses age 2-5 years to test the hypothesis that athletic training might influence the development of atrioventricular (AV) valve regurgitation in young Thoroughbreds. Murmurs of valvular regurgitation were identified and graded on a 1-6 scale. There were 2 sources of auscultation data: 1) 55 2-year-old horses that were examined by auscultation before training commenced and 9 months later when at race fitness; 2) 56 horses age 2-5 years that were examined on one occasion only (25 2-year-olds, 23 3-year-olds, five 4-year-olds and five 5-year olds). All horses in the second data set were in full training and racing regularly at the time of the examination. To conclude the study, 35 horses were selected randomly from both groups of horses and examined with colour-flow Doppler echocardiography. The aim of the final part of the study was to check specificity and sensitivity of auscultation for detection of AV valve murmurs and therefore validate the auscultation findings. Prior to training, the prevalence in 2-year-old racehorses of murmurs of mitral regurgitation and tricuspid regurgitation was 7.3% (4/55) and 12.7% (7/55), respectively. After training, the prevalence proportions increased to 21.8% (12/55) and 25.5% (14/55). After training, one horse developed a murmur characteristic of aortic regurgitation. The differences in murmur prevalence were statistically significant for mitral and tricuspid regurgitation (paired t test results: mitral regurgitation, P = 0.019; tricuspid regurgitation, P = 0.007), as were the differences in mean murmur grade (P = 0.018 and P = 0.0006, respectively). There were no significant effects of age on the prevalence of valvular regurgitation in 56 horses examined at race fitness. Auscultation was a specific (specificity 100%) and reasonably sensitive method for detection of murmurs of mitral and tricuspid regurgitation (mitral regurgitation: positive predictive value 100%, negative predictive value 84%, tricuspid regurgitation: positive predictive value 100%, negative predictive value 65%). These data suggest that the prevalence and grade of murmurs of mitral and tricuspid valvular regurgitation increase in 2-year-old Thoroughbreds after 9 months of athletic training. Whereas the effects of age and growth on the prevalence of murmurs cannot be ruled out from these data, this study suggests that there is an influence of athletic training on the development of atrioventricular valvular regurgitation in flat-racing Thoroughbreds.  相似文献   

20.
REASONS FOR PERFORMING STUDY: Osteoarthrosis (OA) in the distal tarsal joints, bone spavin, is a well known condition which is common in Icelandic horses age 6-12 years. OBJECTIVES: To determine the nature, location and age of appearance of early radiographic and histological changes in the centrodistal tarsal joint (CD) of young Icelandic horses. METHODS: Slab sections from the CD of young Icelandic horses were examined by high detail radiography (age 6 months to 6 years, n = 111) and histology (age 6 months to 4 years, n = 82) to detect and describe the early changes indicative of OA. Horses younger than 5 years were unridden. RESULTS: Chondronecrotic lesions histologically similar to those described in the early pathogenesis of OA were seen in 33% of the joints, located both medially and laterally. Radiographic sclerosis of the subchondral bone was recorded in 60% of the specimens, most often medially. Medial location was not associated with chondronecrosis, but was strongly related to age. Sclerosis was an infrequent finding on the lateral side, and was probably secondary to chondronecrosis in the corresponding part of the joint. Small defects in the subchondral bone were considered to be the most specific radiographic sign of OA as they were strongly associated with chondronecrosis. CONCLUSIONS: The high prevalence of chondronecrosis in the young horses indicates an early onset and slow progression of the disease. The early appearance also shows that the initiation of the disease is unrelated to the use of horses for riding. As clinical manifestation of OA in the distal tarsal joints is most often described in mature or old horses, the first stages of the disease are not likely to result in clinical signs. Subchondral bone sclerosis did not appear to be a primary factor in the development of OA in the CD but was considered to reflect an uneven distribution of biomechanical forces within the joint. POTENTIAL RELEVANCE: The development of OA in the CD of young Icelandic horses seems to be due to poor conformation or joint architecture rather than trauma or overloading. These aetiological factors are likely to be of importance for OA in the distal tarsal joints in other breeds as well. The influence of hindlimb conformation and the architecture of the distal tarsal joints on the biomechanics of joints need to be investigated, preferably by locomotion analysis in young horses.  相似文献   

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