Kinematics of the Reciprocal Apparatus in the Horse

In vivo and in vitro studies concerning the anatomy and the function of the reciprocal apparatus in the horse are described. It appears that the movements of the stifle and hock joints are not fully congruous in spite of their being coupled by this reciprocal apparatus. Anatomical peculiarities are discussed which prevent the hindlimb from being blocked     

Effects of Shortening Breakover at the Toe on Gait Kinematics at the Walk and Trot

Point of breakover, defined as the portion of the hoof last in contact with the ground during the terminal stance phase of a limb, can be influenced by many factors including craniocaudal placement of the shoe. Shortening the point of breakover has been suggested to decrease strain on the deep digital flexor tendon and navicular bone as well as to improve the alignment of the second and third phalanx. The current experiment involved eight sound horses fitted with aluminum plates adhered to their front hooves, which were drilled and tapped to allow additional aluminum plates of various lengths to be attached (the longest plate was placed flush with the toe, while the shortest plate was moved 3.81 cm caudal to the toe). Horses were recorded on video while at the walk and trot over a distance of 70 meters for six repetitions to determine differences in gait kinematics. Results of this study show significant changes in stride kinematics caused by shortening the point of breakover. Retraction of the forelimbs was greatest when breakover was moved 1.27 cm back from the toe (P < .05), and minimum height of the fetlock at the trot was higher on all treatments where the breakover point was moved caudally (P < .05). Some improvements in gait quality were observed when breakover was shortened, although extreme caudal placement of the shoe (negative placement in relation to P3) resulted in a decrease in gait quality as seen by decreased retraction of the forelimb (P < .05) coupled with hoof height occurring earlier in the stride (P < .05).     

Analysis of Speed Characteristics on 1000 m Trot Training Race in Yili Horse

In order to provide some reference on scientific training and determination of horse trot training race, experiment was conducted on analysis of speed characteristic of Yili horse trot training race. The grade of 7 Yili horses 1000 m trot training race and the speed per 50 m were measured, which was used as a research object and sample, by statistical analysis, correlation analysis, the difference of the linear regression method for quantitative analysis. It was resulted that between subsection speed (2 to 18) and average speed were significantly or extremely significantly correlated (P<0.05;P<0.01), the 9^th subsection speed had the highest relevancy; 6 high correlation subsection speeds were choosed for regression analysis, equation:Y=4.039X₉+2.256X₈－2.653X₁₆－1.361X₅－3.739X₁₃+2.529X₁₉－0.728. The experiment preliminary proved the difference among every subsection speed of 1000 m speed training race and the correlation between subsection speed and average speed, establishing a regression equation of subsection speed and average speed.     

Kinematic Characterization of the Menorca Horse at the Walk and the Trot: Influence of Hind Limb Pastern Angle

This paper describes the handled walking and trotting kinematics (linear, temporal, and angular traits) of 35 Menorca Purebred (MEN) stallions, and the relationships among these variables is presented for the first time, along with a discussion of the influence of the hind limb pastern angle on kinematic variables at both gaits. For data collection, all animals, aged between 3 and 10 years old and belonging to 28 different studs, were recorded under the same experimental and environmental conditions, using a three-dimensional (3D) semiautomatic movement analysis system. A total of 24 kinematic variables (temporal, linear, and angular) at the walk and the trot and a morphometric variable measured at the mid stance position of walking (hind pastern angle) were included in this analysis. Angle-time diagrams of the hind pastern angle while walking and trotting normalized to stride duration were also obtained. Generally the MEN stallions' forelimb movements closely resembled the movement characteristics of other European dressage performance breeds, while the hind limb locomotion showed a greater likeness to Iberian dressage Purebreds. Despite this, their ability in collection and propulsion at the walk and the trot was relatively low. The hind limb pastern conformation was partially connected to the hind limb movements for both gaits, with an apparently negative effect of excessively upright pasterns on the amplitude at the trot, which indirectly reduced collection ability.     

The Influence of Speed and Height at the Withers on the Kinematics of Sound Horses at the Hand-Led Trot

The influence of speed and height at the withers on some biokinematic stride parameters (linear, temporal and angular) was measured in 15 Spanish Thoroughbreds (Andalusian Purebred) trotted hand-led along a track; analysis was made of the correlation between speed and height at the withers and of some biokinematic parameters of equine locomotion. Both height at the withers and speed were positively and significantly correlated to the linear parameters examined. Temporal parameters did not reveal a significant correlation with the height at the withers. The correlations with the angular parameters were variable, often being significant for both height at withers and speed, although in most cases the coefficient was relatively low, probably owing to the narrow ranges of speed and height at the withers and their low variability. It was concluded that horses at the hand-led trot tend to have low variability in speed during successive trials, although the speed at which they move does have a significant influence on both linear and temporal stride parameters, and also on several angular parameters, while height at the withers has a major effect on linear parameters but less on angular parameters, and does not affect the temporal parameters.     

Effects of Steel and Aluminum Shoes on Forelimb Kinematics in Stock-Type Horses as Measured at the Trot

To meet the needs of sport horses, horseshoes of various styles and materials have been implemented to enhance performance. Steel shoes are commonly used for their affordability and longevity; however, the use of aluminum horseshoes is being adopted to satisfy the various requirements of certain equestrian activities. Owing to the importance of the allure of movement in many aspects of competitive riding, the lightweight nature of aluminum horseshoes has been recognized to accentuate foreleg action. By performing a repeated-measures crossover study on nine healthy stock-type horses, the effects of these two horseshoe types on forelimb action were analyzed at the trot using two-dimensional kinematics. Horses were trotted in hand for three repetitions over a distance of 50.1 meters on days 4, 18, 32, and 46 postshoeing for two 6-week shoeing cycles. Video footage was collected and analyzed using gait analysis software (EquineTec) for each repetition. The measured stride length, fetlock extension, elbow and knee range of motion, and minimum and maximum elbow angle remained constant between treatments. However, there was a significant treatment effect on minimum carpal angle and maximum hoof height, with aluminum shoes having a larger minimum carpal angle than those in steel shoes (P < .05) and a lower maximum hoof height (P < .05). An overall 3-degree difference in minimum carpal angle and approximate 2.5-cm difference in maximum hoof height was observed between treatments. This finding is of particular importance to performance horse disciplines for which a lesser degree of knee action is desirable.     

伊犁马1000m速步训练赛各阶段静脉血中血气指标变化研究

利用i-STAT血气分析仪检测12匹伊犁马1000 m速步训练赛静息、热身后及赛后即刻、15 min、30 min、60 min时静脉血中的血气指标,并对各血气指标的差异性和相关性进行统计分析。结果表明,运动前后静脉血中PvCO₂、PvO₂、HCO₃、TCO₂、SvO₂和Glu变化差异不显著(P>0.05)。血液pH、BE和Ca²⁺在赛后即刻均明显降低,但经15 min休息后都基本回升到静息水平;K⁺、Hct和Hb在赛后即刻均显著增加(P<0.05),但经15 min休息后都基本回降到静息水平。血液pH与BE、HCO₃呈极显著正相关(P<0.01),与TCO₂浓度呈显著正相关(P<0.05),Hct、Hb与pH和HCO₃呈极显著负相关(P<0.01),与K⁺呈极显著正相关(P<0.01)。因此,BE、HCO₃、TCO₂、Hct和Hb对酸碱平衡均有一定的调节作用;Na⁺、K⁺和Ca²⁺对机体运动具有一定的调节作用。     

Influence of Seminal Plasma Antioxidants and Osteopontin on Fertility of the Arabian Horse

This study was designed to investigate enzymatic antioxidants’ activity and nonenzymatic antioxidants’ levels in seminal plasma of stallions and to relate them with season, age, and fertility of stallions. Fifty ejaculates were collected from six healthy Arabian stallions, 4-22 years old. Ejaculates were evaluated by conventional methods. Five milliliters of each semen sample was centrifuged, and the supernatant seminal plasma was stored at −20°C. Five antioxidants, in addition to osteopontin (OPN) and testosterone, were determined in stallion seminal plasma by using commercial enzyme-linked immunosorbent assay kits. Results revealed that uric acid, ascorbic acid, OPN, and testosterone concentrations and glutathione peroxidase (GPx) activity in stallions’ seminal plasma were high (P < .05) during spring. GPx activity was higher (P < .05) in age group B (11-18 years old) than in age group A (4-10 years old). The effect of stallions’ age on GPx activity in the fertility groups was highly significant (P < .01). OPN concentration was highest (P < .05) in age group A. Uric acid and OPN concentrations and GPx activity in stallions’ seminal plasma and percent of sperm motility were higher (P < .05) in fertility group III (>70%) than in fertility group I (<50%). However, ascorbic acid concentration, catalase activity and percentage of sperm abnormalities were lower (P < .05) in fertility group III than in fertility group I. It was concluded that season and stallion age may affect antioxidant defense systems in stallions’ seminal plasma. The impairment of seminal antioxidants and OPN could lead to low fertility.     

Genetic Diversity and Population Structure of Arabian Horse Populations Using Microsatellite Markers

Understanding the genetic diversity and the relationships among the show Arabian horse populations is a current issue for breeders and professionals. This study aimed to define the relationship among the Desert breed, the Straight Egyptian, and the Polish Arabian populations by considering the historical background of their origin and to verify their genetic diversity. All selected samples were related to Arabian show activities. One hundred forty four hair samples were collected from horses at stud farms having notoriety in the breeding of Arabians from different geographic regions. A set of 17 microsatellites markers for parentage control were used for genotyping. Genetic diversity among and between these populations were evaluated using several statistical methods. All the microsatellites were informative and the marker set analyzed provided 145 alleles. The average number of alleles per locus was 6.52, 6.35, and 7 for the Desert breed, Straight Egyptian, and Polish Arabian, respectively. The high genetic diversity observed within the three populations (0.63-0.71) was associated with a high number of effective alleles. Desert breed and Polish Arabian populations appeared the closest, whereas the Egyptian population was more distant. The significant positive inbreeding coefficient F_IS found in Desert breed, Straight Egyptian, and Polish Arabian horses (0.09, 0.14, and 0.11, respectively) confirmed the deficit of heterozygosity observed in these populations. These results suggested that the three populations have high levels of gene flow or share the same origin and have a recent divergence. This study may highlight the risk of the loss of gene diversity in these populations and help to implement appropriate breeding programs to preserve genetic diversity.     

Ultrasonography and Surgical Treatment of an Unusual Case of Urethral Calculus in an Arabian Horse

This case report records an obstructive urolithiasis due to a large calcium carbonate urethral stone in an 11-year-old Arabian stallion. The stallion had colicky pain, anuria, and reduction in food and water intakes. Palpation of the penis revealed rhythmic contractions of the urethra, a hard mass in the penile urethra at the level of the ischial arch, and a dilated urethra proximal to the mass. Rectal examination revealed a distended and turgid urinary bladder. Passing a urethral catheter revealed a complete urethral obstruction at the level of the ischial arch. Ultrasonography revealed a calculus that appeared as an irregular, hyperechoic arch-like thick line with acoustic shadowing. Subischial urethrotomy was conducted under epidural anesthesia. Uneventful recovery was seen with no recurrence or complications for 12 months of available follow-up. In conclusion, clinical, rectal, and ultrasound examinations are valuable for definite diagnosis of urethral calculi in horses and the subischial urethrotomy appears to be successful in correcting this condition in horses.     

The Impact of Horse Age,Sex, and Number of Riders on Horse Performance in British Eventing Horse Trials

Limited research has been undertaken to determine the impact of horse age, sex, and number of riders on horse performance in British Eventing (BE) horse trials. Improved understanding of this can aid professionals in planning a competition horse’s career. To investigate the impact of age, sex, and number of riders on the peak performance of horses at each of the main levels of BE competitions. The best score from each horse competing in BE horse trials in the years 2008–2018 was recorded, and principal component and hierarchical cluster analysis was performed. Basic data analysis was used to identify variables associated with particular better-performing clusters of horses. The interplay of the combinatory variables was then used to map out the trends in career trajectory for horses competing at each level of competition in the best-performing and worst-performing clusters. The peak performance of mares was worse than geldings and stallions at all levels. At Novice to Advanced, stallions did not perform as consistently with multiple riders as geldings. The age at which the best-performing groups peaked was similar for mares and geldings in all classes, although stallions peaked at an older age than mares and geldings at Novice and Intermediate level. All horses were a minimum of 4-years-old at the time of competition, as per BE rules.     

OIE高健康高性能马匹框架概述

世界动物卫生组织(OIE)为解决赛马跨境移动过程中各国检疫标准不一的问题,促进国际马术赛事的赛马临时进口便利化,提出了高健康高性能(HHP)马匹的新概念。本文从HHP马场和马匹认证、生物安全准则、HHP证书等方面概述HHP马匹实施框架,并回顾了HHP国内外实施现状,展望了其在我国的应用。建立HHP既可以便利赛马跨境移动,又保障良好的动物卫生保护水平,可为更多国家尤其是发展中国家举办高水平国际马术赛事及出境参赛提供更多机会。目前该规则在国际上的实际应用尚处起步阶段,在国内仍处于空白阶段。为进一步推动我国马术运动的可持续发展,应尽快建立一套适宜我国国情的赛马跨境移动检疫监管模式。