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.
Meyer W, Schoennagel B, Kacza J, Busche R, Hornickel IN, Hewicker-Trautwein M, Schnapper A.We studied the esophageal epithelium for keratinization characteristics from samples of domesticated mammals of three nutrition groups (herbivores: horse, cattle, sheep; omnivores: pig, dog, rat; carnivores: cat) using histochemistry (keratins, disulfides), sulfur measurements, and cryo-SEM. Keratins were found in all esophageal layers of all species, except for the equine Stratum corneum. The positive reaction staining of Pan-keratin was remarkable, but decreased in intensity toward the outer layers, whereas in the pig and cat, staining was confined to the corneal layer. The herbivores reveal...
Galvão AM, Szóstek AZ, Skarzynski DJ, Ferreira-Dias GM.Normal reproductive function involves the expression of inflammatory mediators. Regarding the corpus luteum (CL), cytokines promote the cross-talk between immune, vascular and steroidogenic cells, among others. Moreover, TNF, IFNG and FASL were shown to regulate equine CL establishment and regression. We hypothesized that cytokines action on equine CL may be mediated by nitric oxide (NO), through the regulation of endothelial NO synthase (eNOS) expression. TNF increased eNOS mRNA level and NO metabolite (nitrite) production during CL growth. Cytokines combined action (TNF+IFNG+FASL) promoted e...
van Beest FM, Uzal A, Vander Wal E, Laforge MP, Contasti AL, Colville D, McLoughlin PD.Density is a fundamental driver of many ecological processes including habitat selection. Theory on density-dependent habitat selection predicts that animals should be distributed relative to profitability of habitat, resulting in reduced specialization in selection (i.e. generalization) as density increases and competition intensifies. Despite mounting empirical support for density-dependent habitat selection using isodars to describe coarse-grained (interhabitat) animal movements, we know little of how density affects fine-grained resource selection of animals within habitats [e.g. using res...
Cluzel C, Blond L, Fontaine P, Olive J, Laverty S.Adult articular cartilage (AC) has a well described multizonal collagen structure. Knowledge of foetal AC organisation and development may provide a prototype for cartilage repair strategies, and improve understanding of structural changes in developmental diseases such as osteochondrosis (OC). The objective of this study was to describe normal development of the spatial architecture of the collagen network of equine AC using 1.5 T magnetic resonance imaging (MRI) and polarised light microscopy (PLM), at sites employed for cartilage repair studies or susceptible to OC. T2-weighted fast-spin e...
Dixon PM, du Toit N, Staszyk C.There have been many significant and interesting developments in equine dental anatomy during the past 20 years that are of major clinical significance in better understanding the physiology of equine mastication, the etiopathogenesis of some dental disorders, and their safe treatment. The many recent significant developments include descriptions of the enamel infolding of cheek teeth and of infundibular anatomy, including the frequent absence of cementum infilling in many infundibulae, which can lead to infundibular caries. Many important developments in equine dental anatomy are summarized i...
Casey M.Equine dental disease has a high prevalence. Because of developmental, functional, and anatomic differences, limited inference can be made from brachydont dental pathology to that of equine cheek teeth. This article reviews the pathology of equine cheek teeth and their associated oral tissues, with specific information on periodontitis, pulpitis, maxillary infundibular changes, dental fractures, dental overgrowths, mucosal ulceration, and the regenerative capacity of equine teeth.
Foster DL.This article discusses the primary odontogenic problems of the mature performance horse, including wolf teeth; hooks; overbite, overjet, underjet, and wry bite; equine odontoclastic tooth resorption and hypercementosis; infundibular caries; and secondary oral problems. It outlines the author's methods of taking the history, oral examination, and use of diagnostic nerve blocks.
Earley E, Rawlinson JT.This article discusses the classification systems for dental fractures and how the assessment affects treatment options. Diagonal incisor malocclusion is discussed in relation to skull asymmetry and how this commonly relates to premolar and molar occlusion. Oral and radiographic assessment of incisive bone fracture and incisor avulsion is reviewed for determining treatment options. A summary of incisor and canine resorption and hypercementosis is presented. Clinical presentations, staging, and classifications of tooth resorption as well as canine odontoplasty are discussed. Excessive plaque an...
Baxter C.This is a clinician's view of the current state of veterinary dentistry at the level of the general practitioner across the different species. An indication of the work done and the hazards commonly encountered are covered. Conclusions: To increase awareness within the dental profession of the current state of veterinary dentistry.
Viry S, Sleimen-Malkoun R, Temprado JJ, Frances JP, Berton E, Laurent M, Nicol C.In riding, most biomechanical studies have focused on the description of the horse locomotion in unridden condition. In this study, we draw the prospect of how the basic principles established in inter-personal coordination by the theory of Coordination Dynamics may provide a conceptual and methodological framework for understanding the horse-rider coupling. The recent development of mobile technologies allows combined horse and rider recordings during long lasting natural events such as endurance races. Six international horse-rider dyads were thus recorded during a 120 km race by using two t...
Gordon ME, Edwards MS, Sweeney CR, Jerina ML.The objective of this study was to test the hypothesis that feed additives such as chelated minerals, organic Se, yeast culture, direct-fed microbials, and Yucca schidigera extract would improve nutrient digestibility when included in an equine diet. Horses (Quarter Horse geldings 4.5 to 16 yr of age; mean BW 522 kg ± 46 kg) were acclimated to 100% pelleted diets formulated with (ADD) and without (CTRL) commercially available sources of the aforementioned additives followed by a 14-d collection period of feces and urine. Chelated sources of Cu, Zn, Mn and Co were utilized versus sulfated form...
Daly JM, Newton JR, Wood JL, Park AW.Mathematical modelling of infectious disease is increasingly regarded as an important tool in the development of disease prevention and control measures. This article brings together key findings from various modelling studies conducted over the past 10 years that are of relevance to those on the front line of the battle against equine influenza.
Nelis H, D'Herde K, Goossens K, Vandenberghe L, Leemans B, Forier K, Smits K, Braeckmans K, Peelman L, Van Soom A.Equine embryos remain for 6 days in the oviduct and thus there is a need for an in vitro model to study embryo-oviductal interactions in the horse, since this subtle way of communication is very difficult to analyse in vivo. Until now, no equine oviduct explant culture model has been characterised both morphologically and functionally. Therefore, we established a culture system for equine oviduct explants that maintained epithelial morphology during 6 days of culture, as revealed by light microscopy and transmission electron microscopy. We demonstrated the presence of highly differentiated, ta...
Marjamäki PH, Contasti AL, Coulson TN, McLoughlin PD.Movement away from an area or social group in response to increasing density (density-dependent dispersal) is known for most species; why it evolves is fundamental to our understanding of ecology and evolution. However, we have yet to fully appreciate how individuals of varying conditions (e.g., age and sex) might differently consider effects of density (quorum) when deciding to disperse or not, and scale dependence in their sense of quorum. We tracked movements of all individuals of a naturalized population of feral horses (Equus ferus caballus; Sable Island National Park Reserve, Nova Scotia...
Hamza E, Akdis CA, Wagner B, Steinbach F, Marti E.Insect bite hypersensitivity (IBH) is a recurrent allergic dermatitis of horses with similarities to human atopic eczema, caused by bites of insects of the genus Culicoides. Previous studies suggested a dysregulated T cell tolerance to Culicoides allergen in IBH-affected horses. Objective: We have investigated whether the suppressive function of CD4(+) CD25(high) cells is impaired in IBH-affected horses and possible ways to restore it. Methods: CD4(+) CD25(-) cells sorted from peripheral blood mononuclear cells (PBMC) were stimulated with irradiated autologous PBMC pulsed with Culicoides or te...
Mendez D, Büttner P, Speare R.A cross-sectional study of private veterinarians providing equine services in Queensland. Results: The study revealed that a majority of veterinarians would support the introduction of a Hendra virus (HeV) vaccine. Moreover, almost half of the respondents intended to make vaccination a prerequisite to horse patient presentation. However, participants also responded that a vaccine would not reduce the risk sufficiently to cease or downgrade their HeV management plan and infection control measures. Conclusions: When devising promoting and marketing campaigns, government agencies and manufacturer...
Walker VA, Dyson SJ, Murray RC.Development of core muscle strength is important for training and during rehabilitation following injury. A Pessoa training aid (PTA) is a system of ropes and pulleys which is commonly used during equine training and rehabilitation, but there is limited information on its effectiveness. The objective of the study was to determine the effect of the PTA on the temporal, linear and angular kinematics of the working trot. Influence of testing order on effect of a PTA was assessed in four horses. Twelve riding horses were lunged at working trot on a 16 m diameter circle without (WO) and with a PTA ...
Lange-Consiglio A, Rossi D, Tassan S, Perego R, Cremonesi F, Parolini O.We have recently demonstrated that heterologous transplantation of horse amniotic membrane-derived mesenchymal cells (AMCs) can be useful for cell therapy applications in tendon diseases, and hypothesized that these cells may promote tendon repair via paracrine-acting molecules targeting inflammatory processes. To test this hypothesis, here we examined the immunomodulatory characteristics of AMCs and of their conditioned medium (AMC-CM) in vitro, and studied the potential therapeutic effect of AMC-CM in thirteen different spontaneous horse tendon and ligament injuries in vivo. Our results demo...
Sharma R, Barakzai SZ, Taylor SE, Donadeu FX.Despite the high prevalence of skin conditions in the horse, there is a dearth of literature on the culture and biology of equine skin cells, and this is partially attributable to the lack of suitable in vitro skin models. The objective of this study was to develop a three-dimensional (3D) culture system that would support the proliferation and differentiation of equine keratinocytes, similar to that observed in natural epidermis. Cell monolayers were obtained from explants of equine skin and serially passaged as highly pure keratinocyte populations (> 95% of cells), based on their express...
Coleman SJ, Zeng Z, Hestand MS, Liu J, Macleod JN.Sequencing of equine mRNA (RNA-seq) identified 428 putative transcripts which do not map to any previously annotated or predicted horse genes. Most of these encode the equine homologs of known protein-coding genes described in other species, yet the potential exists to identify novel and perhaps equine-specific gene structures. A set of 36 transcripts were prioritized for further study by filtering for levels of expression (depth of RNA-seq read coverage), distance from annotated features in the equine genome, the number of putative exons, and patterns of gene expression between tissues. From ...
Ninomiya S, Anjiki A, Nishide Y, Mori M, Deguchi Y, Satoh T.In stabled horses, behavioral responses to frustration are often observed, especially around feeding time. These behavioral responses are a useful indicator of their welfare. In this study, we investigated the association between this behavioral indicator and DRD4 gene polymorphisms in stabled horses. Twenty one horses housed in two stables were used. The horses were observed for approximately 4 h around feeding over three or more days using focal-sampling and instantaneous-sampling. Horses were genotyped for the A-G substitution in the DRD4 gene. The effects of the A-G substitution (with or w...
Balao da Silva CM, Spinaci M, Bucci D, Giaretta E, Peña FJ, Mari G, Galeati G.The interest on sex sorting by flow cytometry on the equine industry has been increasing over the years. In this work, three different tests were performed in order to evaluate the membrane status of sorted stallion spermatozoa: assessment of binding ability to porcine oocytes, evaluation of acrosome integrity after stimulation with A23187, and detection of tyrosine phosphorylation. These evaluations were made after incubation for 0h, 1.5h and 3h in a capacitating medium. Sorted stallion spermatozoa attached similarly to the porcine oocytes, when compared with control samples. Sorted spermatoz...
Brinkschulte M, Bienert-Zeit A, Lüpke M, Hellige M, Staszyk C, Ohnesorge B.The system of the paranasal sinuses morphologically represents one of the most complex parts of the equine body. A clear understanding of spatial relationships is needed for correct diagnosis and treatment. The purpose of this study was to describe the anatomy and volume of equine paranasal sinuses using three-dimensional (3D) reformatted renderings of computed tomography (CT) slices. Heads of 18 cadaver horses, aged 2-25 years, were analyzed by the use of separate semi-automated segmentation of the following bilateral paranasal sinus compartments: rostral maxillary sinus (Sinus maxillaris ros...
Muniz E, Lobo Ladd AA, Lobo Ladd FV, da Silva AA, Kmit FV, Borges AS, Teixeira R, da Mota LS, Belli CB, de Zoppa AL, da Silva LC, de Melo MP, Coppi AA.Ileocolonic aganglionosis (ICA) is the congenital and hereditary absence of neurons that constitute the enteric nervous system and has been described in various species including humans - Hirschsprung's disease - and horses - overo lethal white syndrome (OLWS). Hirschsprung's disease affects circa 1 in 5,000 live births. At best, this disease means an inability to absorb nutrients from food (humans). At worse, in horses, it always means death. Despite our general understanding of the functional mechanisms underlying ICA, there is a paucity of reliable quantitative information about the structu...
Olsen E, Pfau T, Ritz C.Over ground motion analysis in horses is limited by a small number of strides and restraints of the indoor gait laboratory. Inertial measurement units (IMUs) are transforming the knowledge of human motion and objective clinical assessment through the opportunity to obtain clinically relevant data under various conditions. When using IMUs on the limbs of horses to determine local position estimates, conditions with high dynamic range of both accelerations and rotational velocities prove particularly challenging. Here we apply traditional method agreement and suggest a novel method of functional...
Cotugno R, Gallotta D, d'Avenia M, Corteggio A, Altamura G, Roperto F, Belisario MA, Borzacchiello G.In human cancer cells, BAG3 protein is known to sustain cell survival. Here, for the first time, we demonstrate the expression of BAG3 protein both in equine sarcoids in vivo and in EqS04b cells, a sarcoid-derived fully transformed cell line harbouring bovine papilloma virus (BPV)-1 genome. Evidence of a possible involvement of BAG3 in equine sarcoid carcinogenesis was obtained by immunohistochemistry analysis of tumour samples. We found that most tumour samples stained positive for BAG3, even though to a different grade, while normal dermal fibroblasts from healthy horses displayed very weak ...
Ohmura H, Hiraga A, Matsui A, Aida H, Inoue Y, Asai Y, Jones JH.Yearling horses are typically trained for more than a year before they begin racing; therefore, we questioned how relevant analyses of the initial responses to training are compared to physiological responses that occur over a year of training, and whether young horses with no history of training would respond the same as older horses that had been trained previously. We hypothesised that changes in O2 transport over the last months of a year of training would be different than at the beginning. We trained 5 yearling Thoroughbreds and evaluated metabolism, O2 transport and echocardiograms. Mea...
Licka T, Peham C, Zohmann E.The aim of this study was to establish basic reference data for evaluating 3-dimensional movement of the equine back at the trot. In 22 mature horses without any clinical signs of back pain, the movement of the back was measured during trotting on a treadmill with a system for motion analysis. The position of the markers placed on the head, hooves, skin above the spinous processes of T5, T10, T16, L3 and on 2 of the sacral spines was recorded. The results of all movements were expressed in percent of the horse's height at its withers. At the trot, the maximum lateral movement at the head was 1...
Siegers E, van Wijk E, van den Broek J, Sloet van Oldruitenborgh-Oosterbaan M, Munsters C.Friesian stallions have to complete a 10-week studbook approval test (70-day test) consisting of dressage and driving training for acceptance as a breeding stallion. Training response of the horses to this approval program was evaluated. External workload (EW) of 16 stallions (3.2 ± 0.4 years old) was registered during the 9 weeks preceding the 70-day test (preparation period) and during 70-day test. Ridden indoor standardized exercise tests (SET), measuring heart rate (HR) and plasma lactate concentration (LA) at walk, trot and canter, were performed in week 1 (SET-I), 6 (SET-II) and 10 (SET...
Johnston C, Roepstorff L, Drevemo S, Kallings P.Fast trotting Standardbred horses were filmed along a straight on an oval dirt track. Five consecutive stance phases were analysed to describe the planar kinematics of the distal hindlimb. The rapid changes in the geometry of the distal hindlimb that occur during the early stance phase were studied. The hoof segment was initially braked vertically and moved in the direction of the horse. The hoof moved forward on the track surface for more than 20% of the stance time (ST). Two specific deviations in the otherwise smooth course of the fetlock joint angle appeared at 16 and 29% of ST. Tarsal ang...
Clarke AF.This paper reviews the environmental and host factors which interact to affect the incidence and severity of episodes of respiratory disease in stabled horses. The folly of accepting housing criteria and management practices for the horse, based on direct extrapolations from intensive housing of meat producing animals, is discussed. The factors which affect air hygiene and physical environment of stables are considered in terms of short-term athletic performance and long-term welfare.
Rabb MH, Thompson DL, Barry BE, Colborn DR, Garza F, Hehnke KE.Six lighthorse stallions with previous sexual experience were used to determine the short-term effects of sexual stimulation (SS; 5 min exposure to an estrous mare), SS plus ejaculation (SSE), and no stimulation (control) on serum concentrations of LH, FSH, testosterone, cortisol and prolactin. Stallions received one treatment per day on d 1, 4 and 7. Treatments were assigned such that each stallion 1) received each treatment once and 2) experienced a unique sequence of treatments. Neither SS nor SSE had any consistent effects on LH or FSH concentrations. Testosterone concentrations during con...
Wolc A, Bresińska A, Szwaczkowski T.Twinning is a serious problem in Thoroughbred horses, as most of the multiple pregnancies are miscarried and live foals present lower performance values. The aim of this study was to estimate the heritability and repeatability of twinning in Thoroughbred horses. A total of 12648 pregnancies of 2033 Thoroughbred mares born between 1929 and 1994 in 11 studs were included. The analysis was performed by the use of AI-REML algorithm under three threshold animal models. The first model included effects of stud, mare's birth period and interaction between them as fixed. The second model included the ...
Garber A, Hastie PM, Farci V, McGuinness D, Bulmer L, Alzahal O, Murray JMD.There is a need to develop feeding strategies to prevent the adverse effect of concentrate feeding in high-performance horses fed energy-dense diets aiming to maintain their health and welfare. The objective of this study is to determine the effect of a VistaEQ product containing 4% live yeast Saccharomyces cerevisiae (S. cerevisiae), with activity 5 × 108 colony-forming unit/g and fed 2 g/pony per day, on faecal microbial populations when supplemented with high-starch and high-fibre diets using Illumina next generation sequencing of the V3-V4 region of the 16S ribosomal RNA gene. The four tr...
Sedgwick AD, Morris T, Russell BA, Lees P.Percoll gradients have been used to separate relatively pure populations of viable equine polymorphonuclear (PMN) and mononuclear (MN) cells. In preliminary studies, a continuous density gradient of 70% Percoll solution was used to separate two distinct leucocyte-rich bands. After measurement of the density of each band on the continuous gradient, discontinuous Percoll gradients, using 60% and 75% Percoll solutions, were used to provide a rapid means of separating PMN and MN cells. The yield of viable cells per ml of blood was 3.0 X 10(6) and 3.2 X 10(6) for MN and PMN cells, respectively. Cor...
Giannetto C, Arfuso F, Fazio F, Giudice E, Pietro SD, Bruschetta D, Piccione G.Depending on the intensity, duration and type of physical exercise, equine metabolism has to adapt to nervous, cardiovascular, endocrine and respiratory system requirements. In horses, exercise and training are known to have considerable effects on the mechanisms of hemostatic system involving platelet activity. The aim of the present study was to evaluate the effect of different training schedules on platelet aggregation in 15 Italian Saddle jumping horses. Animals were divided into three equal groups: Group A was subjected to a high intensity-training program; group B to a light training pro...
Daels PF, DeMoraes JJ, Stabenfeldt GH, Hughes JP, Lasley BL.Thirty pregnant mares were assigned to 3 groups: Group 1 (n = 10) mares served as controls; Group 2 (n = 10) mares were treated with altrenogest (44 mg/day) from Day 16 to 80 and Group 3 (n = 10) mares were treated with a luteolytic dose of PGF2 alpha on Day 16 followed by altrenogest (44 mg/day) until Day 80. Concentrations of progesterone and chorionic gonadotrophin (CG) in plasma and oestrogen conjugate (OC) in urine were determined between Days 16 and 80 of gestation. In Group 3, complete luteolysis occurred in all 10 mares following administration of PGF2 alpha. Six of the 10 mares did no...
Pitzer JB, Kaufman PE, Hogsette JA, Geden CJ, Tenbroeck SH.Beginning in November 2007 and continuing until December 2009, weekly stable fly, Stomoxys calcitrans (L.), surveillance was conducted at four equine facilities near Ocala, FL, by using alsynite sticky traps for adults and by searching immature developmental sites for pupae. Adult stable fly trap captures were highly variable throughout the year, ranging from 0 to 1,400 flies per trap per farm. The greatest adult stable fly activity was observed during the spring months of March and April, with weekly three-trap means of 121 and 136 flies per farm, respectively. The importance of cultural cont...
Budik S, Walter I, Tschulenk W, Helmreich M, Deichsel K, Pittner F, Aurich C.Expansion of the equine conceptus can be divided into blastocoel and yolk sac phases. The endodermal layer transforming the blastocoel into the yolk sac is completed around day 8 of pregnancy. From that time, the size of the spherical conceptus increases tremendously due mainly to the accumulation of fluid rather than cell multiplication. In this study, we have investigated the abundance and localisation of Na(+)/K(+)-ATPases and aquaporins (AQP) in the equine conceptus on days 8, 10, 12, 14 and 16 by multiplex reverse transcriptase PCR, Western blot and immunohistochemistry. During conceptus ...
Busoni V, Snaps F, Trenteseaux J, Dondelinger RF.The purpose of this study was to describe the normal magnetic resonance (MR) imaging characteristics of the palmar structures of the equine podotrochlear apparatus by means of retrospective evaluation of MR imaging studies of 16 cadaver limbs. The articular aspect of the distal sesamoid bone was not evaluated in this study. Equine digits were imaged with a human knee radiofrequency coil in a 1.5 T magnetic field, using spin echo (SE) T1-weighted, turbo spin echo proton density (TSE PD)-weighted with and without fat saturation (FS), and FS TSE T2-weighted sequences. The limbs were dissected aft...
Cherdchutham W, Becker C, Smith RK, Barneveld A, van Weeren PR.To test the hypothesis that exercise at very young age may influence the eventual molecular composition (and hence the biomechanical properties) of tendon tissue in the horse, 43 Dutch Warmblood foals were allotted to 3 differently exercised groups (box-rest, box-rest with training and pasture exercise). Twenty-four superficial digital flexor tendons (SDFTs) were collected at age 5 months (8 from each exercise group) and the others were obtained at 11 months after an additional period of light exercise that was equal for all remaining foals and was intended to see if any induced changes would ...
Merritt AM.This article represents an attempt to provide an overview of the current knowledge of equine gastroduodenal secretory and motor activity, with respect to how these functions are controlled and interact. First, the equine gastric mucosal anatomy is discussed in comparison with other monogastric species, with some attention directed at the large nonglandular portion in relation to its function, or lack thereof. Next, control of gastric acid secretion, as assessed by the collection of gastric contents from a cannula or continuous measurement of their changes in pH, is reviewed, pointing out that ...
Phetudomsinsuk K, Sirinarumitr K, Laikul A, Pinyopummin A.One of the semen quality parameters use to determine fertility is the percentage of sperm that express normal morphology. Sperm head morphometry is also correlated with fertility. The objectives of this study were 1) to investigate the sperm morphology and normal sperm head morphometry of Thai native crossbred stallions, and 2) to compare our results with the characteristics of proven fertile sperm from purebred stallions. Methods: Semen samples were collected monthly from nine stallions, of which five were Thai native crossbred (T) and four were purebred of proven fertility (F: F1 was a Stand...
Limone LE.Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a progressive, painful disease, affecting incisors, canines, and cheek teeth. Examination findings include gingival inflammation, gingival recession and/or hyperplasia, subgingival swelling, bulbous enlargement of teeth, associated periodontal disease, pathologic tooth fracture, and/or tooth mobility and loss. Current hypotheses include biomechanical stresses and secondary bacterial involvement. Early recognition allows case management, but it is a progressive disease. Owner education is crucial; horses with complete or multi...
Levine MA.Before the development of firearms, the horse was crucial to warfare and, before the invention of the steam engine, it was the fastest and most reliable form of land transport. It is crucial to the life of nomadic pastoralists on the Eurasian steppe and played a major role in the evolution of human society during the Bronze Age and Iron Age. Understanding the human past requires knowledge of the origins and development of horse husbandry. The problem of being able to identify the early stages of horse domestication is one that many researchers have grappled with for the most part unsuccessfull...
Cappellato A, Miletto Petrazzini ME, Bisazza A, Dadda M, Agrillo C.The perception of different size illusions is believed to be determined by size-scaling mechanisms that lead individuals to extrapolate inappropriate 3D information from 2D stimuli. The Muller-Lyer illusion represents one of the most investigated size illusions. Studies on non-human primates showed a human-like perception of this illusory pattern. To date, it is not clear whether non-primate mammals experience a similar illusory effect. Here, we investigated whether horses perceive the Muller-Lyer illusion by using their spontaneous preference for the larger portion of carrot. In control trial...
Garza F, Thompson DL, French DD, Wiest JJ, St George RL, Ashley KB, Jones LS, Mitchell PS, McNeill DR.Five lighthorse mares were actively immunized against gonadotropin releasing hormone (GnRH) to determine the relative importance of this hypothalamic hormone in the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Five mares immunized against the conjugation protein served as controls. Mares were initially immunized in November and received secondary immunizations 4 wk later, and then at 6-wk intervals until ovariectomy in June. All mares immunized against GnRH exhibited an increase (p less than 0.01) in the binding of tritiated GnRH by plasma, an indication that a...
Bochröder B, Schubert R, Bödeker D.Discs of stripped mucosa from the proximal ventral colon were prepared immediately after slaughter of 8 Shetland cross-breed ponies. The mucosae were fixed in incubation chambers and used in incubation experiments to study the transmucosal fluxes of the amino acids lysine, histidine and arginine (150 min) and of ammonia (90 min). When the amino acid concentrations in the mucosal solution were in the physiological range (2.8-3.0 mmol/l) no transport to the serosal side of the tissue was found. When the concentrations were raised 10-fold, less than 2% of the mucosal amino acid pool was recovered...
Dyer KR, Duncan ID.The intraneural course of nerve fibres in the equine recurrent laryngeal nerve was investigated by partially ligating the nerve at a proximal site, and 3-8 weeks later, tracing the course and spatial relationships of intact and degenerating fibres along the distal stump. This nerve was chosen because of its great length, the fact that it is a nonbranching motor nerve and because of debate about the course of abductor and adductor nerve fibres in the recurrent laryngeal nerve. Six ponies were used and in each the recurrent nerve was partially ligatured about 20 cm from the larynx, using a fine ...
Pedreros M, Ratto M, Guerra M.In the present study, we analysed the molecular mechanism(s) by which melatonin directly affects ovarian function in the mare. In Experiment 1, follicles and corpora lutea (CL) were collected from slaughterhouse ovaries and analysed for melatonin (MT(1)) receptor mRNA and protein. In Experiment 2, CL were collected from slaughterhouse ovaries and cultured in Dulbecco's modified Eagle's medium-F12 medium (control medium) supplemented with 50 ng mL(-1) equine chorionic gonadotrophin (eCG), 1 nM-1 μM melatonin, 1 μM forskolin or 1 μM luzindole. Explants were cultured for 3 h in the presence of...
Catalán J, Yánez-Ortiz I, Gacem S, Papas M, Bonet S, Rodríguez-Gil JE, Yeste M, Miró J.Previous research has determined that irradiation of mammalian sperm with red light increases motility, mitochondrial activity, and fertilization capacity. In spite of this, no study has considered the potential influence of the color of the straw and the extender used. Therefore, this study tests the hypothesis that the response of mammalian sperm to red light is influenced by the color of the straw and the turbidity/composition of the extender. Using the horse as a model, 13 ejaculates from 13 stallions were split into two equal fractions, diluted with Kenney or Equiplus extender, and stored...
Lewis N, Schnauffer K, Hinrichs K, Morganti M, Troup S, Argo C.The use of time-lapse imaging (TLI) in the evaluation of morphokinetics associated with invitro developmental competence is well described for human, cattle and pig embryos. It is generally accepted that embryos that complete early cleavage sooner are more likely to form blastocysts and that timing of later events, such as blastocyst formation and expansion, are predictive of implantation potential and euploid status. In the horse, morphokinetics as a predictor of developmental competence has received little attention. In this study we evaluated the morphokinetics of early equine embryo develo...
Karasek I, Butler C, Baynes R, Werners A.Ectoparasites infestations are a growing concern to horse owners and equine veterinarians alike. Ectoparasites cause significant health and welfare issues and can potentially can serve as vectors for a variety of pathogens. The prevalence of ectoparasites increases around the world, and especially in horses information on the successful prevention and treatment of ectoparasite infestations in scarce and in many instances anecdotal. This poses a challenge to the equine veterinarian and off-label use of drugs can lead to detrimental effects in horses. In this review we describe the current avail...
Hartman W, Schamhardt HC, Lammertink JL, Badoux DM.Rosette strain gauges were bonded to the cranial, caudal, and medial surfaces of the tibia in the middiaphyseal region of 6 adult ponies. While the ponies were walking, the cranial side was mainly subjected to tension, and the caudal side, to compression. The compression strain on the caudal side was 1.5 times greater than the tension strain on the cranial side. None of these principal strains was aligned along the long axis of the bone; both deviated laterally from the long axis. On the medial surface, the principal strain deviated caudally about 40 degrees from the long axis. From analysis o...
Shaw K, Ursini T, Levine D, Richards J, Adair S.Core strengthening and postural stability are desired outcomes of certain therapeutic exercises performed in horses. This study aimed to quantify changes in muscle activation at a walk and trot in horses traveling over eight consecutive ground poles evenly spaced (at 30 inches for walk and 48 inches for trot) in parallel fashion in a straight line, and with hindquarter and abdominal elastic resistance bands applied at 25% stretch. Surface electromyography (sEMG) data were collected for the longissimus dorsi and rectus abdominus muscles in six horses. A 2 × 2 repeated measures ANOVA was perf...
Weitkamp LR, Allen PZ.Ancient origin of the equine vitamin D binding protein (Gc) polymorphism is suggested by the finding of two alleles, Gc(F) and Gc(S), in each of three equine subgenera, Equus, Asinus and Hippotigris. The equine Gc and albumin loci are closely linked (lod score = 6). Although no recombinants were observed, the data are not inconsistent with a map distance similar to the 2 centimorgans reported for the human albumin/Gc linkage relationship. Gametic association between the Gc(F) and Alb(F) alleles appears probable in the American Standardbred horse, perhaps as a result of population structure. Si...
