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Evaluation of Indicators of Weight-Carrying Ability of Light Riding Horses
Abstract
To answer the question of whether horse height, cannon bone circumference, and loin width can be used as indicators of weight-carrying ability in light horses, eight mature horses underwent a submaximal mounted standard exercise test under four conditions: carrying 15, 20, 25, or 30% of their body weight. Heart rate was monitored, plasma lactate concentration was determined in jugular blood samples pre-exercise, immediately post-exercise, and 10 minutes post-exercise, with serum creatine kinase activity determined at the same times as plasma lactate concentrations, with additional samples collected at 24 hours and 48 hours post-exercise. Muscle soreness and muscle tightness scores were determined using a subjective scoring system 24 hours before and 24 hours after exercise. Heart rates remained significantly higher when the horses carried 25 and 30% of their body weight. Plasma lactate concentrations immediately and 10 minutes after exercise differed when horses carried 30% of their body weight compared with 15, 20, and 25% weight carriage. Horses tended to have a greater change in muscle soreness and muscle tightness when carrying 25% of their body weight, and a significant change in soreness and tightness scores was found in horses carrying 30% of their body weight. Loin width and cannon bone circumference were found to be negatively correlated to the changes in muscle soreness and tightness scores. In conclusion, the data suggest that horses with wider loin and thicker cannon bone circumference became less sore when carrying heavier weight loads.
... Weight carrying capacity is important in riding horses and the capacity seems to be associated with back shape (Powell et al., 2008;Stefánsdóttir et al., 2017). In the study by Powell et al. (2008), a negative correlation was found between loin width and muscle soreness after weight carrying in light riding horses. ...
... Weight carrying capacity is important in riding horses and the capacity seems to be associated with back shape (Powell et al., 2008;Stefánsdóttir et al., 2017). In the study by Powell et al. (2008), a negative correlation was found between loin width and muscle soreness after weight carrying in light riding horses. In another study, Icelandic horses with a higher body condition score (BCS) of the back (i.e. ...
... This indicates that height at withers is important for usability in TRh and not only for performance at breeding tests (Holmström and Philipsson, 1993;Kristjansson et al., 2016;Ste-fánsdóttir et al., 2021). However, height at withers has not been found to be correlated with weight carrying capacity in previous studies (Powell et al., 2008;Stefánsdóttir et al., 2017). In this study, the usability of the horses was evaluated by the owner and only reflected the owner's perspective, which might not be the same as the horse's physiological response during exercise. ...
Many horse breeds are used for a variety of tasks and studies have shown within breed variations in conformation depending on the task. The Icelandic horse is used for several tasks, e.g. leisure riding, competitions and tour riding. Research about conformation and relationship to subjectively assessed performance (usability) in Icelandic horses used by tourist companies and riding schools (TRh) are lacking. Back condition score has been shown to be associated with weight carrying capacity in the breed. However, the association between back condition score and angle and performance in Icelandic horses participating in a breed evaluation field test (BEFTh) and usability in TRh has not been investigated previously. The aim of the study was to compare body measurements in BEFTh and TRh and examine the relationship with riding ability in BEFTh and usability in TRh. Data of height at withers, back and croup, body condition score (BCS) and back angle were collected in 48 BEFTh (age 8 ± 2 years) and 65 TRh (age 14 ± 5 years). Transversal back angle at the 18th thoracic vertebra was determined using a flexible curve ruler. A questionnaire was used to evaluate the relationship between body measurements and owners’ assessment of usability in TRh. The relationship between back condition score and angle and riding ability was evaluated in BEFTh. Compared with TRh, BEFTh had a greater difference between height at withers and height at back and croup, lower BCS and greater back angle ( ). In TRh, height were positively correlated with usability ( ). Back condition score and angle were not associated with riding ability in BEFTh or usability in TRh ( ). In conclusion, body measurements differs between BEFTh and TRh and further studies are needed to investigate if the same conformation traits are associated with good performance in BEFTh and usability in TRh.
... As the bodyweight of the horse riders increases [7,11,14], an increasing load negatively impacts the health of the horse's back [15], physical exercise of the horse [16,17], and horse welfare [18]. Therefore, the appropriate fit of rider size to the horse size is becoming increasingly important in riding horse usage [19,20]. ...
... Therefore, the greatest changes noted currently in the red and blue color components are in line with conventional thermal results, where two temperature measures, the minimal and maximal, differed both between effort states [33,64] and different rider bodyweights [20,21,34]. Those differences reflect the thermal energy emission increase with the increase in metabolic energy produced by loaded muscle units [15,16,67,68]. Interestingly, as the DispEn algorithm returned entropy measures that were not very sensitive to rotation, translation, or image size [57], DispEn may be applicable in smaller or larger image areas, unlike the entropy-related GLCM texture features [20]. ...
As obesity is a serious problem in the human population, overloading of the horse’s thoracolumbar region often affects sport and school horses. The advances in using infrared thermography (IRT) to assess the horse’s back overload will shortly integrate the IRT-based rider-horse fit into everyday equine practice. This study aimed to evaluate the applicability of entropy measures to select the most informative measures and color components, and the accuracy of rider:horse bodyweight ratio detection. Twelve horses were ridden by each of the six riders assigned to the light, moderate, and heavy groups. Thermal images were taken pre- and post-exercise. For each thermal image, two-dimensional sample (SampEn), fuzzy (FuzzEn), permutation (PermEn), dispersion (DispEn), and distribution (DistEn) entropies were measured in the withers and the thoracic spine areas. Among 40 returned measures, 30 entropy measures were exercise-dependent, whereas 8 entropy measures were bodyweight ratio-dependent. Moreover, three entropy measures demonstrated similarities to entropy-related gray level co-occurrence matrix (GLCM) texture features, confirming the higher irregularity and complexity of thermal image texture when horses worked under heavy riders. An application of DispEn to red color components enables identification of the light and heavy rider groups with higher accuracy than the previously used entropy-related GLCM texture features.
... Briefly, equine obesity has been found to cause an accumulation of adipose tissue around internal organs such as the kidney and heart [76,77]. Excess adipose tissue contributes to the weight of horses, and weight carriage has a clear impact on the effort required to exercise during both race-type events [78] and non-racing exercise [79][80][81]. Adiposity is also associated with movement asymmetry [82]. Overweight horses have a harder time dissipating heat, which could contribute to early fatigue [83]. ...
Obesity is an important health concern in horses, along with humans and companion animals. Adipose tissue is an inflammatory organ that alters the insulin-signaling cascade, ultimately causing insulin dysregulation and impaired glucose metabolism. These disruptions can increase the risk of metabolic disease and laminitis in horses and may also impact energy metabolism during exercise. A single bout of exercise, along with chronic exercise conditioning, increases insulin sensitivity and glucose disposal via both contraction- and insulin-mediated glucose uptake pathways. Regular exercise also increases calorie expenditure, which can facilitate weight (as body fat) loss. This paper explores the metabolic pathways affected by adiposity, as well as discusses the impact of exercise on insulin metabolism in horses.
... En los caballos deportivos evaluados, las medidas morfométricas de volumen (alzada, longitud corporal y perímetro torácico), las medidas del músculo glúteo medio y los índices musculares se relacionaron con el área muscular dorsal de los animales. En tal sentido, Powell et al. (2008) sugieren incluir la evaluación del área muscular equina para ajustar la capacidad de carga, ya que, según sus hallazgos, animales con un lomo más ancho, pueden tolerar cargas más pesadas que caballos con lomos más estrechos, siendo similar en peso; por esta razón, las variaciones individuales en la proporción muscular podrían influir en el bienestar animal y la capacidad de carga del peso soportado de los caballos deportivos. ...
Existen varias metodologías para determinar la condición corporal del caballo deportivo, siendo unas más objetivas que otras; sin embargo, la escala de condición corporal es la más usada para estimar las reservas corporales de animales en actividad atlética. El objetivo del estudio fue estimar, por métodos no invasivos, el espesor de grasa subcutánea y desarrollo muscular de caballos deportivos, de una academia de Cundinamarca y calcular algunos índices que definen la composición corporal. Se escogieron 29 caballos adultos (9 hembras, 20 machos), de cuatro tipos raciales; caballo deporte colombiano, criollo, polo argentino, Pura sangre inglés. Para evaluar la grasa subcutánea se usó el puntaje de condición corporal (PCC) escala Henneke, el ultrasonido en tiempo real UTR, midiendo espesor de grasa dorsal y de cadera. La musculatura se determinó usando UTR a nivel dorsal, midiendo el ojo del lomo y el glúteo medio. Se tomaron pesos y medidas morfométricas: altura de cruz, longitud corporal, perímetro torácico. Con estas medidas corporales o ecográficas se calcularon índices de desempeño o composición corporal: índice corporal (IC), índice de carga al paso-1 y al trote-2 (IC1 y IC2), % de grasa corporal (%GC), Índice de masa corporal (IMC), relación perímetro torácico–altura cruz (PT:AC), índice muscular (IM) e índice musculoesquelético (IME). Los índices de carga y de composición corporal indicaron diferencias entre tipos raciales (p<0,05). Entre índices de engrasamiento se presentaron correlaciones altas con PCC (EGD 0,78 y IMC 0,99). Algunos índices (IC1, IC2) serían indicadores indirectos de la relación fin-bienestar en los animales.
... This study added weights to the horse's backs via saddle, weight bags and feed bags attached to the horses, to remove any potential effects of the rider's ability. Powell, et al. [105] compared horses carrying additional weight of four different percentages of bodyweight (15,20,25, and 30% of BW). These additional weights were in the form of a rider with different weights of tack. ...
Simple Summary
Increased incidence of obesity in our equine population has clear negative impacts on equine health, such as increasing the risk of equine metabolic syndrome and laminitis. Excessive adipose tissue likely also has negative impacts on exercise performance, due to a combined inflammatory response and the effects of excessive weight carriage on work effort and limb health. This review explores research conducted in these areas.
Abstract
There is ample research describing the increased risk of health concerns associated with equine obesity, including insulin dysregulation and laminitis. For athletes, the negative effect of weight carriage is well documented in racing thoroughbreds (i.e., handicapping with weight) and rider weight has been shown to impact the workload of ridden horses and to some degree their gait and movement. In many groups of competitive and athletic horses and ponies, obesity is still relatively common. Therefore, these animals not only are at risk of metabolic disease, but also must perform at a higher workload due to the weight of their adipose tissue. Excess body weight has been documented to affect gait quality, cause heat stress and is expected to hasten the incidence of arthritis development. Meanwhile, many equine event judges appear to favor the look of adiposity in competitive animals. This potentially rewards horses and ponies that are at higher risk of disease and reinforces the owner’s decisions to keep their animals fat. This is a welfare concern for these animals and is of grave concern for the equine industry.
Excessive adiposity in horses is associated with equine metabolic syndrome and laminitis, and additional weight due to fat accumulation may cause further stress on the horse. This study aimed to determine the effect of additional weight carriage on work effort in horses, as estimated by changes in heart rate (HR) and body temperature (Temp). Eight mature mixed-breed horses were paired based on body size in a randomised crossover study. Each day tested a pair of horses with one horse carrying additional weight (15% of body weight; to represent approximately 3 body condition scores) and the other horse serving as a control, with treatments reversed the following week. Heart rate was determined before adding the weight, after a 2 h period of stall rest (prior to the exercise bout), and at the end of a 34 min exercise challenge of walking and trotting on an automated exerciser. Temp was recorded prior to exercise and after the horses were removed from the exerciser. Two-way ANOVA was conducted to determine the effect of exercise and weight carriage on HR and Temp, and paired t-tests were used to compare differences in HR and Temp pre- and post-exercise. HR increased with exercise ( ) and was higher following exercise in horses carrying additional weight ( ). Exercise increased Temp ( ) and the difference in Temp was greater in the weight-carrying group ( ). This study documents the effect of weight carriage that could be imposed with body fat, in addition to the known health detriments of adiposity.
Horseracing has been a prominent part of Mongolia’s history and culture for centuries during which time it has featured prominently in festivals and ceremonial events. Thanks to Mongolia’s traditionally pastoral lifestyle, Mongolian children were said to be ‘born in the saddle’ however, in the twenty-first century, the number of child jockeys has expanded rapidly and the conditions they experience have changed as tourism has fueled increasing demand for more racing. Regulation and enforcement in horseracing have not kept pace with this change, and what little accountability there is often erroneously placed on riders and their families, rather than horse owners and trainers who exploit loopholes in the rules and rural poverty for their own benefit. Protecting child jockeys requires a careful balance of respecting and preserving important cultural heritage practices while also resisting the pressure to excuse risk and children’s rights violations in the name of ‘culture’. The revenue generated by tourism and horseracing provides an opportunity for systemic change that acknowledges the new business model of Mongolian horseracing and leverages its value to address rural poverty and establish procedures to better regulate horseracing. Through this model, the rights of child jockeys can be protected while preserving the tradition of horseracing and using it to improve quality of life in the community.KeywordsAbuseChild jockeysChildren’s rightsCultural heritageExploitationHorseracing human rightsMongoliaRural poverty
Hypothesis: The goal of this study was to evaluate the impact of three different adaptive devices used to facilitate therapeutic horseback riding for riders with cerebral palsy (CP), the horses, and the assisting persons. The study hypothesis was that there is no difference in clinical benefit to the rider; stress or physical saddle pressure to the horse; or the level of exertion required from assisting persons when using any of the three adaptive devices. Population: Individuals with varying disability due to cerebral palsy who participated in a therapeutic horseback riding program at a Professional Association of Therapeutic Horsemanship (PATH) Premier Accredited Center.
Intervention: Therapeutic horseback riding sessions using one of three adaptive devices. Comparators: Two commonly used adaptive devices (English saddle and bareback pad with backrider), and one recently developed, less-used device (Independence saddle). Outcomes: Clinical benefit for the individual with Cerebral Palsy was evaluated using an osteopathic musculoskeletal exam score. Equine stress was evaluated using a horse stress behavior ethogram. Physical pressure under the saddle of the horse was evaluated using a
Pliance Saddle pad under each adaptive device. Required level of exertion by assisting persons was measured using an assistant exertion score.
Conclusion: Therapeutic riding using an English saddle, a backriding pad with backrider, or an Independence saddle, by individuals with various degrees of disability, does not cause excessive stress or result in excessive pressure to the horse. Using one assistive device over another also does not appear to change the likelihood of clinical benefit to the rider. However, exertion scores for assisting persons were lower when the Independence saddle was used compared to the English saddle or backriding pad. Adaptive devices that allow an individual with CP to improve function, ride more independently, provide some respite for the side walker and do not cause undue stress or frustration to the horse would be a great addition to the therapeutic regimen. Based on the results of this study, the Independence saddle is a viable alternative to the English saddle or the backriding pad for riders that would otherwise need extensive assisting person support in a therapeutic riding program.
It has been hypothesized that a major objective of morphological adaptation in limb-bone diaphyses is the achievement of uniform regional safety factors between discrete cortical locations (e.g. between cranial and caudal cortices at mid-diaphysis). This hypothesis has been tested, and appears to be supported in the diaphyses of ovine and equine radii. The present study more rigorously examined this question using the equine third metacarpal (MC3), which has had functionally generated intracortical strains estimated by a sophisticated finite element model. Mechanical properties of multiple mid-diaphyseal specimens were evaluated in both tension and compression, allowing for testing of habitually tensed or compressed regions in their respective habitual loading mode (`strain-mode-specific' loading). Elastic modulus, and yield and ultimate strength and strain, were correlated with in vivo strain data from a previously published finite element model. Mechanical tests revealed minor variations in elastic modulus, and yield and ultimate strength in both tension and compression loading, while physiological strains varied significantly between the cortices. Contrary to the hypothesis of uniform safety factors, the MC3 has a broad range of tension (caudo-medial, 4.0; cranio-lateral, 37.7) and compression (caudo-medial, 5.7; cranio-lateral, 68.9) safety factors.
The purpose of this study was to compare the analgesic effect of pulsating ultrasound treatment and placebo on delayed onset of muscle soreness produced by an eccentric exercise bout. In addition, the effect of pulsed ultrasound on muscular performance following an eccentric exercise bout was studied. Eighteen untrained subjects were randomly assigned to: 1) ultrasound (A) [N = 6] over the areas of concentrated muscle soreness, i.e. proximal vastus lateralis and distal vastus medialis; 2) placebo ultrasound (B) [N = 6]; and 3) no therapeutic intervention (C) [N = 6]. Baseline data were recorded for maximum isometric knee extension contraction (MVC), maximum knee extension torque (MT), knee extension work (W), and soreness perception (SP). All values were subsequently reassessed 24 and 48 hours after intense muscular activity. Immediately following the 24 hour reassessment the A group received ultrasound treatment, the B group received placebo ultrasound, while the C group received no treatment. Percent deviation from baseline of SP, MVC, MT and W were significantly less for A than B and C (p less than 0.05) at 48 hours post muscle soreness bout. These data indicate that pulsed ultrasound accelerates restoration of normal muscle performance, and thus is effective in decreasing delayed onset of muscle soreness. The mechanism for decreasing soreness perception in the muscle is unknown, but may be related to decreasing intramuscular pressure and/or decreasing the inflammatory response.
To answer the question whether an experienced rider or a dead weight influences a horse's workload and/or its locomotion, 9 well trained Dutch Warmblood horses, fully accustomed to treadmill exercise, underwent a submaximal standardised treadmill exercise test under 3 different conditions: unloaded, mounted by an experienced rider of 90 kg and loaded with 90 kg of lead. Heart rate was monitored continuously and plasma lactate concentrations were determined in venous jugular blood samples immediately before and 2 and 10 min after exercise. Temporal and angular stride variables were measured in fore- and hindlimbs at the walk (1.7 m/s), trot (4.0 m/s) and canter (7.0 m/s) with a modified CODA-3 computerised kinematic analysis system. Peak heart rates during exercise, and recovery heart rates thereafter were significantly lower in the unloaded horses compared to the mounted and lead-loaded horses. Plasma lactate concentrations immediately and 10 min after exercise were also significantly lower in the unloaded horses than in the mounted and lead-loaded horses. No differences were found in heart rate and plasma lactate concentration between the mounted and lead-loaded horses. Relative stance duration increased comparing the unloaded to the mounted and the lead-loaded horses (P<0.05). Small, but significant, differences were also observed in the fetlock extension and the maximal fetlock range of motion; both increased with loading. In conclusion, an experienced rider and a dead weight influence both workload and locomotion in exercising horses. Minimal differences were found between dead lead weight and a rider.
Ground reaction force (GRF) measurements are often normalised to body mass to facilitate inter-individual comparisons. The objective of this study was to explore the effect of a rider on the GRFs and fetlock joint kinematics of trotting horses. The subjects were 5 dressage-trained horses and 3 experienced dressage riders. Ground reaction force measurements and sagittal view videotapes were recorded as the horses trotted at the same velocity in hand (3.49 f 0.52 d s) and with a rider (3.49 f 0.46 d s). Data were time-normalised to stance duration. Ground reaction force measurements were expressed in absolute terms and normalised to the system mass (horse or horse plus rider). All the horses showed changes in the same direction when comparing the ridden condition with the in-hand condition. There was an increase in the absolute peak vertical GRFs of the fore-and hindlimbs with a rider. However, the mass-normalised peak vertical GRFs were lower for the ridden condition, with the peak occurring later in the forelimbs and earlier in the hindlimbs compared with the in-hand condition. Maximal fetlock angle and its time of occurrence were similar for the 2 conditions, but the fore fetlock joint was more extended during the later part of the stance phase in ridden horses. The presence of a rider appeared to affect the GRFs and fetlock joint kinematics differently in the fore-and hindlimbs, and the ridden horse did not seem to be equivalent to a proportionately larger horse. This should be considered when normalising for body mass in studies comparing horses in hand and ridden horses.
The behaviour of cortical bone under load is strain rate-dependent, i.e. it is dependent on the rate at which the load is applied. This is particularly relevant in the galloping horse since the strain rates experienced by the bone are far in excess of those recorded for any other species. In this study the effect of strain rates between 0.0001 and 1 sec-1 on the mechanical properties of equine cortical bone were assessed. Initially, increasing strain rates resulted in increased mechanical properties. Beyond a critical value, however, further increases in strain rate resulted in lower strain to failure and energy absorbing capacity. This critical rate occurred around 0.1 sec-1 which is within the in vivo range for a galloping racehorse. Analysis of the stress-strain curves revealed a transition in the type of deformation at this point from pseudo-ductile to brittle. Bones undergoing brittle deformation are more likely to fail under load, leading to catastrophic fracture and destruction of the animal.
The perception of muscle soreness is probably due to the activation of free nerve endings around muscle fibers. These nerve endings serve as receptors of noxious stimuli associated with muscle damage. Modulation of soreness may take place at the peripheral receptor sites or at a central or spinal level. This multilevel modulation may explain the large intersubject variation in the perception of muscle soreness. The type of exercise that produces the greatest degree of soreness is eccentric exercise, although isometric exercise may also result in soreness. Eccentric exercise has been shown to produce muscle cellular damage and decrements in motor performance as well. Although training is considered to prevent muscle soreness, even trained individuals will become sore following a novel or unaccustomed exercise bout. Thus, training is specific to the type of exercise performed. Our laboratories have shown that the performance of a single exercise bout will have an effect on a subsequent similar bout given up to 6 weeks later. Thus, when a second bout of downhill running was given to subjects 6 weeks after the first bout, with no intervening exercise, less soreness developed, and muscle damage was estimated to be reduced. The explanation for this long-lasting prophylactic or "training effect" is currently under investigation in our laboratories.
The application of transmission ultrasonics to the equine cannon holds promise as a method of monitoring metacarpal and metatarsal development, quality and integrity under a variety of experimental and field conditions. The validity of relating the velocities of sound pulses transmitted through the cannon to the mechanical breaking strengths of these bones was tested in two studies. Breaking strengths calculated from the sound velocities through sections of the metacarpal bones from 14 yearling ponies and 12 yearling horses were highly correlated with the mechanical breaking strengths of those sections (r = .907 and .927, respectively; P less than .01). Sound velocities through the cannons of the horses before sacrifice ranged from 2,453 to 3,130 m/s and were correlated with their mechanically determined breaking strengths (193 to 262 X 10(6) N/M2; r = .673; P less than .01). The correlation coefficient increased to .912 when the sound velocities were adjusted for the sound-delaying effects of the overlying soft tissues. In a third study, 13 horses were weaned at 2 to 4 mo of age and were fed diets providing either 100 or 130% of National Research Council (NRC) energy and protein recommendations. Metacarpal and metatarsal development was monitored monthly for 15 mo via transmission ultrasonics. Sound velocities, breaking strengths calculated from velocities adjusted for estimated soft tissue cover, measured bone mediolateral diameters and cannon diameters minus estimated soft tissue increased as quadratic functions of chronologic age (r greater than .840; P less than .0001). None of these variables was significantly affected by diet, leg or sex. These studies have demonstrated that the use of transmission ultrasonics to estimate and monitor metacarpal and metatarsal breaking strengths in the live horse is reliable, reproducible, simple, accurate and valid. They also suggest that NRC energy and protein recommendations meet the requirements for maximum bone growth and development in well-managed young equines.