Equine Science encompasses the study of horses and their management, health, and performance. This field integrates various scientific disciplines such as biology, genetics, nutrition, physiology, and veterinary medicine to understand and improve the well-being and capabilities of horses. Areas of focus include equine anatomy, reproduction, behavior, and disease prevention. Research in equine science aims to enhance horse care, optimize training and performance, and address health challenges. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine science, providing insights into the latest advancements and methodologies in the field.
Zhang C, Svensson RB, Montagna C, Carstensen H, Buhl R, Schoof EM, Kjaer M, Magnusson SP, Yeung CC.Tendon is a highly organized, dense connective tissue that has been demonstrated to have very little turnover. In spite of the low turnover, tendon can grow in response to loading, which may take place primarily at the periphery. Tendon injuries and recurrence of injuries are common in both humans and animals in sports. It is unclear why some areas of the tendon are more susceptible to such injuries and whether this is due to intrinsic regional differences in extracellular matrix (ECM) production or tissue turnover. This study aimed to compare populations of tenocytes derived from the tendon c...
Williamson KM, Wheeler S, Kerr J, Bennett J, Freeman P, Kohlhagen J, Peel AJ, Eby P, Merritt T, Housen T, Dalton C, Durrheim DN.In June 2019 the first equine case of Hendra virus in the Hunter Valley, New South Wales, Australia was detected. An urgent human and animal health response took place, involving biosecurity measures, contact tracing, promotion of equine vaccinations and investigation of flying fox activity in the area. No human or additional animal cases occurred. Equine vaccination uptake increased by over 30-fold in the surrounding region in the three months following the case. Black flying fox and grey-headed flying fox species were detected in the Valley. The incident prompted review of Hendra virus resou...
Sardinia, an island located to the west of Italy in the Mediterranean Sea, boasts three native horse breeds: Giara, Sarcidano, and Sardinian Anglo-Arab. Here, we have investigated for the first time three loci of the non-recombining region of the Y chromosome (NRY) in 34 stallions from these breeds and performed a phylogenetic analysis of the maternal relationships among 178 previously published mitochondrial control regions. We found that the current NRY diversity of Sardinian horse breeds is linked to three haplotypes (HT), all identified within Sarcidano. Each breed showed a typical HT: HT1...
Guinnefollau L, Gee EK, Norman EJ, Rogers CW, Bolwell CF.Horses are used in practical teaching classes in many equine and veterinary science degree programmes to develop and refine the handling and clinical skills of students. In this study, the activities of 24 teaching horses grouped in three herds were investigated over an entire calendar year. Although also used for research and general husbandry, teaching-related activities were the predominant use of the horses. Herd B was used for a greater number of teaching sessions (median = 28, IQR = 27-29.5 per year) than herds M (median = 21, IQR = 20-21 per year) and T (median = 19.5, IQR = 13.75-25.5 ...
Javanshir S, Younesi Soltani F, Dowlati G, Parham A, Naderi-Meshkin H.Managing tendon healing process is complicated mainly due to the limited regeneration capacity of tendon tissue. Mesenchymal stem cells (MSCs) have potential applications in regenerative medicine and have been considered for tendon repair and regeneration. This study aimed to evaluate the capacity of equine adipose tissue-derived cells (eASCs) to differentiate into tenocytes in response to platelet-derived growth factor-BB (PDGF-BB) and growth differentiation factor-6 (GDF-6) in vitro. Frozen characterized eASCS of 3 mares were thawed and the cells were expanded in basic culture medium (DMEM...
Ebel F, Vallejos A, Gajardo G, Ulloa O, Clavel E, Rodríguez-Gil JE, Ramírez-Reveco A.The aim of this study was to evaluate seasonal changes in basic parameters of sperm quality and freezability behaviour of ejaculates from 10 fertile heavy draft stallions. A total of 140 ejaculates were collected, processed and evaluated during both the breeding (September-November) and non-breeding seasons (April-June). Fresh semen was evaluated for volume, concentration, total spermatozoa per ejaculate, plasma membrane integrity and total sperm motility. Cryopreserved samples were evaluated for plasma membrane integrity and sperm motility by the CASA system, and for the freezability index (F...
Catalán J, Papas M, Gacem S, Mateo-Otero Y, Rodríguez-Gil JE, Miró J, Yeste M.Previous studies in other mammalian species have shown that stimulation of semen with red-light increases sperm motility, mitochondrial activity, and fertilizing capacity. This study sought to determine whether red-light stimulation using a light emitting diode (LED) at 620-630 nm affects sperm motility and structure of motile subpopulations, sperm viability, mitochondrial activity, intracellular ATP levels, rate of O consumption and DNA integrity of horse spermatozoa. For this purpose, nine ejaculates were collected from nine different adult stallions. Upon collection, semen was diluted in Ke...
Gaitskell-Phillips G, Martín-Cano FE, Ortiz-Rodríguez JM, Silva-Rodríguez A, Rodríguez-Martínez H, Gil MC, Ortega-Ferrusola C, Peña FJ.Some stallions yield ejaculates that do not tolerate conservation by refrigeration prior to artificial insemination (AI), showing improvement after removal of most of the seminal plasma (SP) by centrifugation. In this study, the SP-proteome of 10 different stallions was defined through high-performance liquid chromatography with tandem mass spectrometry and bioinformatic analysis in relation to the ability of the ejaculates to maintain semen quality when cooled and stored at 5°C. Stallions were classified into three groups, depending on this ability: those maintaining good quality after direc...
DeBoer M, Konop A, Fisher B, Martinson K.Thermoregulation is an energy-expensive process, which can be mitigated by blanketing horses in cold climates, potentially preventing weight loss or leading to decreased feed intake. The objective of this study was to evaluate feed intake, body weight (BW), and body condition scores (BCSs) in blanketed and nonblanketed horses. In October 2019, 16 mature adult horses were blocked by breed and BCS and randomly assigned to a blanketed (n = 8) or nonblanketed (n = 8) treatment; blankets were placed. Data were collected in December 2019 and January 2020 in River Falls, Wisconsin. During the study...
Kumar P, Mehta JS, Ravi SK, Dedar RK, Purohit GN, Legha RA, Tripathi BN, Talluri TR.The present study was conducted with the hypothesis that addition of cholesterol to the extender would stabilize the sperm membranes by increasing the cholesterol-to-phospholipid (C:P) ratio and would result in an improved post-thaw semen quality and reduce oxidative stress in the jack (Martina franca) semen. Forty-eight ejaculates from six jacks were collected and analyzed for the present study. The freshly collected semen sample of each jack stallion was divided into five equal fractions after addition of the primary extender without cholesterol-loaded cyclodextrin (CLC) (C) and with 1, 1.5,...
Bergmann IM.The idea of what is natural has particular relevance in the thoroughbred racing and breeding discourse. It guides breeding regulations; influences how the thoroughbreds' behaviour is perceived and has implications for husbandry, handling, training and racing practices. This study investigates how key industry and animal advocacy informants based in the US, Australia and the UK conceptualise naturalness within the context of common racing practices that potentially impact the horses' welfare. The informants were interviewed using semi-structured interviewing and photo-elicitation. Four common i...
Teixeira ACB, Valle GR, Riveros JAN, Diniz JHW, Wenceslau RR, Monteiro GA, Leme FOP, Oliveira LZ.The aim of this study was to evaluate the effect of equine chorionic gonadotropin (eCG) at the end of progesterone (P4) treatment on follicular and luteal characteristics during transition period (TP) and reproductive breeding season (RP). A total of 13 crossbred mares were distributed in two experimental groups in the spring and summer (n = 26). The animals received intravaginal P4 (1.9 g) releasing device from D0 to D10. On removal of P4 device, the mares received 400 IU of eCG (eCG group) or saline solution (control group). Human chorionic gonadotropin (hCG; 1.750 IU) was administered (Dh...
Loos CMM, McLeod KR, Stratton SC, van Doorn DA, Kalmar ID, Vanzant ES, Urschel KL.Activation of the mechanistic target of rapamycin (mTOR)-controlled anabolic signaling pathways in skeletal muscle of rodents and humans is responsive to the level of dietary protein supply, with maximal activation and rates of protein synthesis achieved with 0.2 to 0.4 g protein/kg body weight (BW). In horses, few data are available on the required level of dietary protein to maximize protein synthesis for maintenance and growth of skeletal muscle. To evaluate the effect of dietary protein level on muscle mTOR pathway activation, five mares received different amounts of a protein supplement t...
Golafshan N, Vorndran E, Zaharievski S, Brommer H, Kadumudi FB, Dolatshahi-Pirouz A, Gbureck U, van Weeren R, Castilho M, Malda J.One of the important challenges in bone tissue engineering is the development of biodegradable bone substitutes with appropriate mechanical and biological properties for the treatment of larger defects and those with complex shapes. Recently, magnesium phosphate (MgP) doped with biologically active ions like strontium (Sr) have shown to significantly enhance bone formation when compared with the standard calcium phosphate-based ceramics. However, such materials can hardly be shaped into large and complex geometries and more importantly lack the adequate mechanical properties for the treatment ...
Auclair-Ronzaud J, Jousset T, Dubois C, Wimel L, Jaffrézic F, Chavatte-Palmer P.Gestational length is highly variable in horses ranging from 320 to 360 days. Thus, determining parturition time is an important challenge for the horse industry. Body temperature can be used in cows and ewes as an indicator of parturition. Thus, the aim of this study is to determine if temperature can also be used as indicator of foaling. Thirty-nine mares were monitored over two foaling seasons (2018 and 2019). They were housed in 16 m stalls with access to pasture in group three times a week from 10:00 to 16:00. Night watch as well as video monitoring was ensured during foaling periods. Bo...
Dahlgren AR, Scott EY, Mansour T, Hales EN, Ross PJ, Kalbfleisch TS, MacLeod JN, Petersen JL, Bellone RR, Finno CJ.Long non-coding RNAs (lncRNAs) are untranslated regulatory transcripts longer than 200 nucleotides that can play a role in transcriptional, post-translational, and epigenetic regulation. Traditionally, RNA-sequencing (RNA-seq) libraries have been created by isolating transcriptomic RNA via poly-A selection. In the past 10 years, methods to perform ribosomal RNA (rRNA) depletion of total RNA have been developed as an alternative, aiming for better coverage of whole transcriptomic RNA, both polyadenylated and non-polyadenylated transcripts. The purpose of this study was to determine which librar...
Ferrer MS, Canisso IF, Ellerbrock RE, Podico G, Lister BN, Hurley DJ, Kline K, Palomares RA.Freezing cooled-transported semen allows veterinarians and breeders to collect and process the semen of stallions on farm, and then ship the semen to a semen freezing center. There, however, is a lack of standardization of shipping and freezing protocols. The objectives were to optimize and simplify protocols to freeze cooled-shipped semen. In Experiment 1, cooled-transported semen was centrifuged at room temperature or 5 °C before freezing. Sperm variables (motility, membrane integrity, acrosome integrity, membrane fluidity) were evaluated before and after freezing. Centrifugation temperat...
Dominguez EM, Moreno-Irusta A, Rodriguez MB, Salamone DF, de Arruda RP, Losinno L, Giojalas LC.The successful use of assisted reproduction techniques (ART) depends in part on the sperm physiological status. Several sperm selection procedures have been applied to improve quality of sperm population when using the ART. There has previously been development of a Sperm Selection Assay (SSA) for humans which is based on the attraction of capacitated sperm by chemotaxis towards progesterone (P), resulting in an enriched sperm population with an optimal physiological status similar to capacitated spermatozoa, with these cells having very little DNA fragmentation and optimal concentrations of r...
Fukuda K, Kuroda T, Tamura N, Mita H, Kasashima Y.Platelet-rich plasma (PRP) therapy has been widely applied in various medical fields including humans and horses. This study aimed to establish an optimal activation method to stably and reproducibly maximize the concentrations of platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-β1 (TGF-β1) contained in equine PRP. Autologous PRP was prepared from 11 Thoroughbreds. For the activation test, PRP was activated by either a single freeze-thaw cycle (Fr) or adding calcium and autologous serum containing thrombin (Ca). PDGF-BB and TGF-β1 concentrations in Fr, Ca, nonactiv...
Wilkins CA, Nankervis K, Protheroe L, Draper SB.Static assessment and grouping of riders by competition level are prevalent in equestrian coaching practice and research. This study explored sagittal pelvic tilt in 35 competitive dressage riders to analyse the relationship between static and dynamic postures and assess the interaction of competition level. Riders were assessed using optical motion capture on a riding simulator at halt and in walk, trot, and left and right canter. Mean, minimum and maximum pelvic tilt, and range of motion (ROM) were measured as the pitch rotation of a rigid body formed by markers placed on the rider's left/ri...
Guindos-Sanchez L, Lucena-Anton D, Moral-Munoz JA, Salazar A, Carmona-Barrientos I.Cerebral palsy (CP) is a permanent disorder of the posture and movement, which can result in impairments of gross motor function, among others. Hippotherapy (HPT) is an emerging intervention to promote motor recovery in patients with neurological disorders, providing a smooth, precise, rhythmic, and repetitive pattern of movement to the patient. The main objective of this systematic review and meta-analysis of randomized controlled clinical trials was to analyze the effectiveness of HPT interventions on gross motor function in subjects with CP. The following databases were searched in May 2019...
Elmeua González M, Šarabon N.Equestrian sports have been a source of numerous studies throughout the past two decades, however, few scientists have focused on the biomechanical effects, including muscle activation, that the horse has on the rider. Because equitation is a sport of two (the horse-human dyad), we believe there is a need to fill in the knowledge gap in human biomechanics during riding. To investigate the differences between novice and advanced riders at a neuromuscular level we characterized the motor output of a set of riders' key muscles during horse riding. Six recreational riders (24 ± 7 years) and nine ...
Garber A, Hastie P, McGuinness D, Malarange P, Murray JA.Abrupt dietary changes, as can be common when managing horses, may lead to compositional changes in gut microbiota, which may result in digestive or metabolic disturbances. The aim of this study was to describe and compare the faecal microbiota of ponies abruptly changed from pasture grazing ad libitum to a restricted hay-only diet and vice versa. The experiment consisted of two, 14-day periods. Faecal samples were collected on day 0 and days 1-3,7,14 after abrupt dietary change from grass to hay and from hay to grass. Microbial populations were characterised by sequencing the V3-V4 region of ...
Ricord M, Andrews FM, Yñiguez FJM, Keowen M, Garza F, Paul L, Chapman A, Banse HE.Phenylbutazone is commonly prescribed for treatment of various painful or inflammatory disorders in horses, but is associated with gastrointestinal (GI) adverse effects. Anecdotally, many practitioners prescribe omeprazole concurrently with phenylbutazone to reduce development of equine gastric ulcer syndrome (EGUS), but the efficacy and safety of this practice remains unknown. Objective: To evaluate the effect of omeprazole on phenylbutazone-induced equine glandular gastric disease (EGGD) and equine squamous gastric disease (ESGD). Methods: Randomised block experimental design. Methods: Twent...
Herrera C.Embryo cryopreservation is normally performed with great success in species like humans and cattle. The large size of in vivo-derived equine embryos and the presence of a capsule-impermeable to cryoprotectants-have complicated the use of embryo cryopreservation in equine reproduction. A breakthrough for this technique was obtained when large equine embryos could be successfully cryopreserved after collapsing the blastocoel cavity using a micromanipulation system. High pregnancy rates have been obtained when vitrification is used in combination with embryo collapse.
Goldstein DM, Engiles JB, Rezabek GB, Ruff CB.The elongated, distally tapered limbs of horses are adapted for high-speed locomotion. Because these traits are artificially selected for in modern racehorses, they operate at a morphological extreme with a high risk of fracture. Racehorses are subject to different training and racing regimes depending on their breed and gait, and are therefore an interesting model to examine bone functional adaptation under variable biomechanically intense conditions. This study compares bone structural properties in the third metacarpal (MCIII) of Thoroughbred (n = 9) and Quarter Horse (n = 11) racehorses, u...
Oldenhof H, Wolkers WF, Sieme H.In modern livestock breeding, cryopreserved semen is routinely used for artificial insemination. Sperm cryopreservation allows for long-term storage of insemination doses and secures reproduction at a desired time point. In order to cryopreserve semen, it needs to be carefully processed to preserve its vital functions after thawing. In this chapter, we describe the processes involved in cryopreservation of bull, stallion, and boar sperm. These include preparation of diluents, dilution of sperm in primary and freezing extender, slow cooling from room temperature to 5 °C, packaging of insemina...
The Journal of heredityAugust 3, 2016
Volume 107, Issue 6 537-543 doi: 10.1093/jhered/esw042
Norton EM, Mickelson JR, Binns MM, Blott SC, Caputo P, Isgren CM, McCoy AM, Moore A, Piercy RJ, Swinburne JE, Vaudin M, McCue ME.Recurrent exertional rhabdomyolysis (RER) in Thoroughbred and Standardbred racehorses is characterized by episodes of muscle rigidity and cell damage that often recur upon strenuous exercise. The objective was to evaluate the importance of genetic factors in RER by obtaining an unbiased estimate of heritability in cohorts of unrelated Thoroughbred and Standardbred racehorses. Four hundred ninety-one Thoroughbred and 196 Standardbred racehorses were genotyped with the 54K or 74K SNP genotyping arrays. Heritability was calculated from genome-wide SNP data with a mixed linear and Bayesian model, ...
Montgomery PC, Dorrington KJ, Rockey JH.Three independent methods have been used
to determine the molecular weights of the heavyand light-polypeptide chain subunits of equine yGab-,
yGc-, and yT-immunoglobulins. Extensively reduced
and alkylated proteins were filtered through standard
columns of Sephadex G-100 or G-200 in 8 M urea405
M propionic acid. Subunit molecular weights were obtained from the linear elution volume, V,, us. logarithm
molecular weight relationship defined for each column
with rabbit yG-globulin heavy and light chains and
horse heart cytochrome c. Molecular weights also were
determined by equilibrium se...
Brinkmann L, Gerken M, Riek A.Outdoor group housing is increasingly recognized as an appropriate housing system for domesticated horses. The objective of this study was therefore to investigate the effect of potential feed shortage in semi-natural horse keeping systems in winter on animal health and welfare. In 10 female Shetland ponies blood concentrations (NEFA, total protein (TP), total bilirubin (TB), beta-hydroxybutyrate (BHB) and thyroxine (T4)), body mass and the body condition score (BCS) were monitored for 7 months including a 4 months period of feed restriction in five of the 10 ponies. Restrictively fed animals ...
Soares JH, Brosnan RJ, Fukushima FB, Hodges J, Liu H.Anesthetic blood solubility predicts pharmacokinetics for inhaled agents and is essential for determination of blood anesthetic concentrations from end-tidal gas concentrations using Henry's Law. Though used to model anesthetic effects in humans, there are limited interspecies solubility comparisons that include modern haloethers. This study aimed to measure hematocrit-adjusted blood:gas anesthetic partition coefficients (λ B:G) for desflurane, sevoflurane, isoflurane, and methoxyflurane in humans and animals. Methods: Whole blood was collected from 20 rats, 8 horses, and 4 each of cats, catt...
Leśniak K, Whittington L, Mapletoft S, Mitchell J, Hancox K, Draper S, Williams J.Despite the likelihood that a horse's mass influences hoof morphology, empirical evidence is lacking. A clearer understanding of factors influencing hoof shape could enable prevention, or better treatment, of foot-based disorders; common causes of equine lameness. The study's aim was to investigate the relationship between horse body size, in terms of mass and height, and fore hoof dimensions. A further aim was to determine changes in the occurrence of hoof asymmetry as body size increases. Height, mass, and fore hoof dimensions; coronet band width (CBW); hoof base width (HBW); dorsal hoof wal...
Pearson RA, Archibald RF, Muirhead RH.Four cattle, sheep, ponies and donkeys were fed dehydrated lucerne, early-cut hay, later-cut hay or barley straw in a Latin square-based design for four periods of 35 d. In the first sub-period animals were fed the diets ad libitum (1-21 d) and in the second sub-period they were fed the same diet restricted to 0.75 of ad libitum intake (days 22-35). Measurements of forage intake, apparent digestibilities and gastrointestinal mean retention times (MRT) were made in the last 7 d of each sub-period. Differences between species in voluntary DM intake (VDMI; g/kg live weight (LW)(0.75) and g/LW) we...
Valenchon M, Lévy F, Górecka-Bruzda A, Calandreau L, Lansade L.The present study investigated the influence of temperament on long-term recall and extinction of 2 instrumental tasks in 26 horses. In the first task (backward task), horses learned to walk backward, using commands given by an experimenter, in order to obtain a food reward. In the second task (active avoidance task), horses had to cross an obstacle after a bell rang in order to avoid emission of an air puff. Twenty-two months after acquisition, horses exhibited perfect recall performance in both tasks. Accordingly, no influence of temperament on recall performance could be observed for either...
Pearce GP, May-Davis S, Greaves D.To investigate the occurrence of geometrical asymmetries in the macro-architecture of left and right femurs from Thoroughbred racehorses previously used in competitive training and racing in New South Wales, Australia. Methods: Detailed postmortem measurements were made of 37 characteristics of left and right femurs from eleven Thoroughbred racehorses euthanased for reasons unrelated to the study. Measurements focused on articulating surfaces and sites of attachment of muscles and ligaments known to be associated with hindlimb locomotion. Results: Five measurements were significantly larger in...
Eades SC.All cases of laminitis are characterized by failure of the attachment of the epidermal cells of the epidermal laminae to the underlying basement membrane of the dermal laminae despite the diversity of diseases that underlie the syndrome. The preponderance of evidence supports roles for inflammation, metabolic derangement, endothelial and venous dysfunction, and matrix degradation as causes of laminitis. Inflammation, oxidant stress, and matrix degradation may be factors common to each of these mechanisms that lead to the laminar damage of laminitis. The understanding of the pathophysiology and...
van Beek FE, de Cocq P, Timmerman M, Muller M.Injuries of horses might be related to the force the rider exerts on the horse. To better understand the loading of the horse by a rider, a sensor was developed to measure the force exerted by the rider on the stirrups. In the study, five horses and 23 riders participated. Stirrup forces measured in sitting trot and rising trot were synchronised with rider movements measured from digital films and made dimensionless by dividing them by the bodyweight (BW) of the rider. A Fourier transform of the stirrup force data showed that the signals of both sitting and rising trot contained 2.4 and 4.8 Hz...
The Journal of hereditySeptember 13, 2011
Volume 102, Issue 6 753-758 doi: 10.1093/jhered/esr091
Guastella AM, Zuccaro A, Criscione A, Marletta D, Bordonaro S.Genetic diversity and relationship among 3 Sicilian horse breeds were investigated using 16 microsatellite markers and a 397-bp length mitochondrial D-loop sequence. The analysis of autosomal DNA was performed on 191 horses (80 Siciliano [SIC], 61 Sanfratellano [SAN], and 50 Sicilian Oriental Purebred [SOP]). SIC and SAN breeds were notably higher in genetic variability than the SOP. Genetic distances and cluster analysis showed a close relationship between SIC and SAN breeds, as expected according to the breeds' history. Sequencing of hypervariable mitochondrial DNA region was performed on a ...
Gaitskell-Phillips G, Martín-Cano FE, Ortiz-Rodríguez JM, Silva-Rodríguez A, Gil MC, Ortega-Ferrusola C, Peña FJ.Although cryopreservation is widely used in animal breeding, the technique is still suboptimal. The population of spermatozoa surviving the procedure experiences changes attributed to alteration in their redox regulation. In order to expand our knowledge regarding this particular aspect, the proteome in fresh and frozen thawed aliquots of equine spermatozoa was studied to identify the proteins most severely affected by the procedure. If alteration of redox regulation is a major factor explaining cryodamage, proteins participating in redox regulation should be principally affected. Using a spli...
Mawdsley A, Kelly EP, Smith FH, Brophy PO.A linear assessment trait evaluation system is proposed to allow quantitative description of the static conformation of the horse. Measurements were made on 27 selected traits. The system was tested initially for repeatability of measurements on 4 horses. Twenty-one of the selected traits were satisfactory and 6 proved unsatisfactory in terms of reproducibility. A population of 101, superior 2- and 3-year-old Thoroughbreds and 19 premium Thoroughbred stallions were similarly assessed. More than 65% of the traits exhibited large (CV > 10%) phenotypic variation within the sampled population. ...
Sekhar VC, Plapp BV.The binding of NAD+ to liver alcohol dehydrogenase was studied by stopped-flow techniques in the pH range from 6.1 to 10.9 at 25 degrees C. Varying the concentrations of NAD+ and a substrate analogue used to trap the enzyme-NAD+ complex gave saturation kinetics. The same maximum rate constants were obtained with or without the trapping agent and by following the reaction with protein fluorescence or absorbance of a ternary complex. The data fit a mechanism with diffusion-controlled association of enzyme and NAD+, followed by an isomerization with a forward rate constant of 500 s-1 at pH 8: E E...
Birch HL, Smith TJ, Poulton C, Peiffer D, Goodship AE.Partial rupture occurs most often to the superficial digital flexor tendon (SDFT) of the forelimb at the mid-metacarpal level. In this study, we tested the hypothesis that the mid-metacarpal region of the SDFT has the smallest cross sectional area (CSA) and a similar collagen content to other regions and, therefore, represents a weak point in the tendon. The SDFT was collected from the forelimbs of 9 horses. Each tendon was marked at 7 different levels from the origin of the accessory ligament to the phalangeal region. The CSA, water content and collagen content was measured at each level. The...
Scarth JP, Teale P, Kuuranne T.A detailed understanding of equine drug metabolism is important for detection of drug abuse in horseracing and also in veterinary drug development and practice. To date, however, no comprehensive review of equine drug metabolism has been published. The majority of literature regarding equine drug metabolite profiles is derived from sports drug detection research and is generally targeted at detecting marker metabolites of drug abuse. However, the bulk of the literature on equine drug metabolism enzymology is derived from veterinary studies aimed at determining the molecular basis of metabolism...
Forssmann A.The islets of Langerhans of the equine pancreas were examined with the electron microscope after immersion or perfusion fixation. Five cell types could be distinguished after fixation by either technique: 1. A-cells, situated at the center of the islets, 2. B-cells, containing mostly "pale granules" and constituting the principal cell type of the periphery of the islets, 3. D-cells, also located mainly at the periphery of the islets, 4. G-cells, found at the edge of the islets and in the exocrine pancreas, and 5. S-cells, (small granule cells), which are relatively few in number and occur only...
Hess MF, Roser JF.The large amount of testicular estrogens produced by the stallion is unique compared to the amounts found in other domestic species. Although the cellular locale of the cytochrome P450 aromatase (P450arom) enzyme that converts C19 androgens to C18 estrogens has been identified in the Leydig cell of adult equine testis, the location in the immature equine testis is not known. The goal of this work was to localize the enzyme in colts and stallions during sexual development. Testes were obtained from prepubertal (n=7), pubertal (n=6), and postpubertal (n=8) colts and stallions during both the bre...
Simhofer H, Griss R, Zetner K.The main objective of this study was to evaluate an endoscopic examination protocol for routine dental examination in horses. The oral cavities of 300 standing, sedated horses were examined under field and hospital conditions with a rigid endoscope using a standardised technique that included examination of the occlusal, lingual (palatal) and buccal surfaces of all cheek teeth rows. The most common cheek teeth abnormalities detected were sharp enamel edges (present in 96.3% of horses), focal overgrowths (64.3%), fissure fractures (54.3%), diastemata (24.3%) and infundibular hypoplasia/caries (...
Harman J.Examining the fit of the saddle is perhaps the most important aspect of examining a horse with a suspected back problem. If the back problem is corrected and a poorly fitting saddle is placed on the back, the problems will return. An ill-fitting saddle contributes to direct and compensatory lower leg lameness making it even more imperative to correct the fit. A correctly fitting saddle enhances both the horse and rider's ability to perform with accuracy, lightness, and freedom of movement.
BAER H, KABAT EA, KNAUB V.Blood group substances have been isolated from the saliva of human beings of blood group B and from the linings of individual horse stomachs. The properties of the human B substances are similar to those of hog and human blood group substances previously isolated. The horse substances showed lower hexosamine and reducing sugar and higher total and non-hexosamine nitrogen than do the materials from the other species. Materials isolated from individual horse stomachs possess either A or B activity or both. Certain stomachs yielded products of identical analytical composition but with neither blo...
Pickett BW, Sullivan JJ, Byers WW, Pace MM, Remmenga EE.The effect of centrifugation of diluted and undiluted semen on equine and bovine spermatozoan motility and fertility was examined, as was the effect of seminal plasma and dilution on stallion spermatozoa during incubation before and after freezing. Centrifugation at 370 g or 829 g was not detrimental (P greater than 0.05) to prefreeze or postfreeze motility if a final concentration of 10% seminal plasma was present. A reduction of seminal plasma from 10% to 2% significantly (P smaller than 0.05) reduced motility. A centrifugal force of 956 g significantly reduced prefreeze but not postfreeze m...
Guérin G, Bailey E, Bernoco D, Anderson I, Antczak DF, Bell K, Biros I, Bjørnstad G, Bowling AT, Brandon R, Caetano AR, Cholewinski G, Colling D....A low-density, male-based linkage map was constructed as one of the objectives of the International Equine Gene Mapping Workshop. Here we report the second generation map based on testing 503 half-sibling offspring from 13 sire families for 344 informative markers using the CRIMAP program. The multipoint linkage analysis localized 310 markers (90%) with 257 markers being linearly ordered. The map included 34 linkage groups representing all 31 autosomes and spanning 2262 cM with an average interval between loci of 10.1 cM. This map is a milestone in that it is the first map with linkage groups ...
