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.
Autio E, Heiskanen ML, Mononen J.Accommodating weanling horses in loose housing (sleeping hall with deep-litter bed and paddock) environments in winter at northern latitudes exposes the nonhuman animals to low ambient temperatures. We determined the heat loss of nine weanling horses in a cold environment by infrared thermography to assess their thermoregulatory capacity. The rate of heat loss was 73.5 to 98.7 W/m2 from the neck and 69.9 to 94.3 W/m2 from the trunk. The heat loss was higher at -16 degrees C than at 0 degrees C and -9 degrees C (p=.01), indicating that the lower critical temperature may have been between -9 d...
Cran DG.Many tens of thousands of calves resulting from artificial insemination (AI) have been born worldwide after XY sperm separation and commercial production is underway in several countries. Accuracy of sex selection is some 90% and can be achieved both in research facilities and at AI studs in rural locations. Most facilities sort X- sperm which have also be utilised for superovulation and embryo transfer projects and for in vitro fertilisation (IVF) as well as AI. Sort rates of some 15 x 10(6) sperm/h are currently achievable and are used for low dose insemination, generally at 2 x 10(6) frozen...
Morris GJ, Faszer K, Green JE, Draper D, Grout BW, Fonseca F.The cellular damage that spermatozoa encounter at rapid rates of cooling has often been attributed to the formation of intracellular ice. However, no direct evidence of intracellular ice has been presented. An alternative mechanism has been proposed by Morris (2006) that cell damage is a result of an osmotic imbalance encountered during thawing. This paper examines whether intracellular ice forms during rapid cooling or if an alternative mechanism is present. Horse spermatozoa were cooled at a range of cooling rates from 0.3 to 3,000 degrees C/min in the presence of a cryoprotectant. The ultra...
Quinn BA, Hayes MA, Waelchli RO, Kennedy MW, Betteridge KJ.During the third week of pregnancy, the equine conceptus is enclosed within a capsule, the glycan composition of which changes at around day 16 (ovulation = day 0) when the conceptus becomes immobilized (fixed) in the uterine lumen. Our objective was to characterize the process of fixation by identifying changes in major capsule-associated proteins. Individual equine conceptuses (n = 55) were collected transcervically by uterine lavage between days 13.5 and 26.5. Major proteins extracted from capsules were compared with those in fluids from the uterus and yolk sac by SDS-PAGE. Until day 14, a ...
Aurich C, Seeber P, Müller-Schlösser F.To maintain the fertility of stallion spermatozoa during cooled storage, extender media are added to semen. In this study, three semen extenders were compared: EquiPro which contains defined caseinates and whey proteins instead of dried skim milk. The extender is provided in dry form and dissolved in distilled water prior to use. EquiPro TM has the same composition as EquiPro but is provided in a sterilized ready-to-use liquid form. AndroMed-E contains soybean lecithin as protein source. Semen was collected from seven stallions. Ejaculates were divided into three aliquots, diluted with the dif...
El-Sabban ME, El-Khoury H, Hamdan-Khalil R, Sindet-Pedersen S, Bazarbachi A.Colloss and Colloss-E are sterile acellular lyophilizates extracted from bovine and equine bone matrix, respectively. Animal and clinical studies have shown that these xenogenic bone matrix extracts (BMEs) are effective as bone graft substitutes. In this report, we investigated the effect of Colloss and Colloss-E on human adult in vitro-expanded bone marrow-derived mesenchymal stem cells (BMMSCs). Specifically, we assessed whether these xenogenic BMEs induced osteoblastic differentiation of cultured BMMSC. We show that BMMSCs treated with either Colloss or Colloss-E exhibited characteristic os...
Mancini RA, Ramanathan R.Injection-enhancement of beef with lactate improves color stability; however, the mechanism is unclear. Thus, our objectives were to assess the effects of sodium lactate on equine myoglobin redox stability in vitro. Oxymyoglobin at pH 5.6 (50mM sodium citrate) and pH 7.4 (50mM sodium phosphate) was incubated at 4°C with lactate (0, 5, 10, 100, or 200mM) and myoglobin redox form was determined using absorbance spectra. Metmyoglobin formation at pH 5.6 and 7.4 was significantly (P<0.05) decreased by lactate at concentrations of 100 and 200mM. In general, increasing lactate concentration from...
Schober D, Aurich C, Nohl H, Gille L.Cryopreservation of spermatozoa is of essential importance for artificial insemination and breeding programs in horses. Besides other factors, spermatozoal motility depends on mitochondrial energy metabolism. Based on changes of single mitochondrial functions it has been suggested that mitochondrial damage during cryopreservation could be a major reason for diminished post thaw semen quality. However, it is still unclear to which extent this influences the whole bioenergetic performance of mitochondria and whether this plays a role during routine cryopreservation procedures. Therefore, it was ...
Strand E, Braathen LC, Hellsten MC, Huse-Olsen L, Bjornsdottir S.The Icelandic horse is a pristine breed of horse which has a pure gene pool established more than a thousand years ago, and is approximately the same size as living and extinct wild breeds of horses. This study was performed to compare the length of the skeletal growth period of the "primitive" Icelandic horse relative to that reported for large horse breeds developed over the recent centuries. This information would provide practical guidance to owners and veterinarians as to when the skeleton is mature enough to commence training, and would be potentially interesting to those scientists inve...
Gandini M.To compare 3 dorsal techniques for arthrocentesis of the distal interphalangeal joint in horses with regard to ease of performing the technique and to determine the role of operator experience in ease of performing these techniques. Methods: Observational study. Sample Population-Forelimbs from 17 equine cadavers and 12 horses (16 joints) undergoing arthrocentesis for therapeutic or diagnostic purposes. Methods: In both forelimbs from 7 of the equine cadavers, 3 arthrocentesis techniques (dorsal perpendicular, dorsolateral, and dorsal inclined) were performed in random order by a single experi...
Bigley RF, Gibeling JC, Stover SM, Hazelwood SJ, Fyhrie DP, Martin RB.Materials, including bone, often fail due to loading in the presence of critical flaws. The relative amount, location, and interaction of these flaws within a stressed volume of material play a role in determining the failure properties of the structure. As materials are generally imperfect, larger volumes of material have higher probabilities of containing a flaw of critical size than do smaller volumes. Thus, larger volumes tend to fail at fewer cycles compared with smaller volumes when fatigue loaded to similar stress levels. A material is said to exhibit a volume effect if its failure prop...
Bedenice D.One of the fundamental skills required for practicing evidence-based medicine is the development of a well-built clinical question, which specifies the patient group or problem, intervention, and outcome of interest. For this purpose, various "levels of evidence" have been developed in the human literature, which rank the validity of evidence. Our established conclusions and advice are thus supported by specific "grades of recommendations," which are intended to give an indication of the "strength" of a clinical recommendation. This article was compiled with these principles in mind.
Bertone JJ.The nature of the equine industry and equine veterinary medicine often requires veterinarians to prescribe drugs with little evidence for a drug's formulation safety or efficacy, or even assurance of the chemistry of the drug used. This means that equine veterinarians must remain skeptics and understand the limitations in their ability to attribute safety and efficacy to a particular drug or treatment. An evidence-based approach to pharmacology demands rigorous testing and an unbiased analysis of results.
Caston SS, Reinertson EL.Musculoskeletal disorders comprise a large portion of the conditions treated by equine veterinarians. Surgical intervention is the treatment of choice in many cases. The body of literature describing and exploring surgical correction of musculoskeletal disorders in horses is steadily growing but still lacking. At this juncture, we can use what information we have with the understanding that as the quality of research advances, we should apply stricter standards to the evidence we use to answer our clinical questions.
Eliashar E.The first aim of this article is to review the progress made in the field of distal limb biomechanics. By understanding limb biomechanics, it is then possible to review the rationale behind a few of the more common techniques that veterinarians routinely use when treating their patients and to evaluate the evidence in support of them.
Brinsko SP.Many procedures performed as part of routine broodmare practice are based on sound clinical judgment and experience or scientific evidence; however, others are based on perceived problems and needs to address them. This article presents four procedures commonly used in broodmare practice, for which there is questionable evidence to substantiate their use.
Uhlinger CA.This article focuses on what has been established concerning the interaction of equine parasites and their hosts, highlighting those issues for which convincing data are still lacking. There is a compelling need for the participation of the veterinarian in the design of appropriate anthelmintic treatments and prevention strategies.
Gillingwater K, Büscher P, Brun R.The animal pathogenic protozoan, Trypanosoma evansi, leads to a wasting disease in equines, cattle and camels, commonly known as Surra. It is extensively distributed geographically with a wide range of mammalian hosts and causes great economical loss. Trypanosoma equiperdum causes a venereal disease called Dourine in horses and donkeys. Chemotherapy appears to be the most effective form of control for T. evansi, whereas infections caused by T. equiperdum are considered incurable. Due to emerging drug resistance, efficient control of T. evansi is severely threatened, emphasising the urgent need...
Kramer J, Coates JR, Hoffman AG, Frappier BL.To describe surgical approaches to the equine cranium and brain for limited craniectomy. Methods: Descriptive anatomic study. Methods: Equine cadavers (n=7). Methods: Head and neck sections from cadavers were used to establish techniques for exposing areas of the equine brain. Three basic approaches were used: rostrotentorial, suboccipital, and transfrontal. Techniques were adapted from small animal descriptions and modified to account for anatomic differences. Results: Descriptions of the rostrotentorial, suboccipital, and transfrontal approaches to the equine cranium and brain were defined. ...
Gandini G, Pizzi F, Stella A, Boettcher PJ.The aim of this work was to compare costs, in the horse, cattle, sheep, swine, and rabbit species, for the creation of gene banks for reconstruction of an extinct breed, using different strategies: embryos-only, embryos in combination with semen, and semen-only. Three cost measures were used: time required for population reconstruction, cost for creation of the gene bank, number of years-keeping-female to reach reconstruction. Semen costs were estimated across four scenarios: the presence or absence of a commercial market for semen, purchase of semen donors, and semen extracted from the epidid...
Ibrahim S, Steinbach F.In addition to the 379 monoclonal antibodies (mAbs) tested in the animal homologues section of HLDA8, another 155 mAbs were screened at the Institute for Zoo and Wildlife Research, Berlin for cross-reactivity with equine leukocytes. For this purpose, one colour flow-cytometric analysis was performed as screening test. This additional screening indicated further 16 mAbs as positive with staining homologous to human pattern, 1 mAb with weak (positive) reactivity, 11 mAbs with positive, but likely not valuable staining, 12 mAbs with alternate expression pattern from that expected from human immun...
Larenza MP, Knobloch M, Landoni MF, Levionnois OL, Kronen PW, Theurillat R, Schatzmann U, Thormann W.The pharmacokinetics of ketamine and norketamine enantiomers after administration of intravenous (IV) racemic ketamine (R-/S-ketamine; 2.2 mg/kg) or S-ketamine (1.1 mg/kg) to five ponies sedated with IV xylazine (1.1mg/kg) were compared. The time intervals to assume sternal and standing positions were recorded. Arterial blood samples were collected before and 1, 2, 4, 6, 8 and 13 min after ketamine administration. Arterial blood gases were evaluated 5 min after ketamine injection. Plasma concentrations of ketamine and norketamine enantiomers were determined by capillary electrophoresis and wer...
Kirkpatrick JF, Turner A.Intensive population management by means of fertility control has been shown to change the age profile of a wild horse herd. The primary change has been an increase in the number and percent of older animals, as expected, but also the appearance of new and older age classes. An examination of direct effects of fertility control on two groups of treated animals shows a significant increase in longevity over non-treated animals that is associated with contraceptive treatment. The mean age at death (MAD) was calculated for 128 wild horses for which precise birth and death dates were known, includ...
Huser CA, Davies ME.Chondrocyte apoptosis is an important factor in the progression of osteoarthritis. This study aimed to elucidate the mechanisms involved upstream of caspase 9 activation and, in particular, calcium signaling and mitochondrial depolarization. Methods: Articular cartilage explants obtained from healthy horses were subjected to a single impact load (500-gm weight dropped from a height of 50 mm) and cultured in vitro for up to 48 hours. Chondrocyte death was quantified by the TUNEL method. Release of proteoglycans was determined by the dimethylmethylene blue assay. Weight change was measured, and ...
Theurillat R, Knobloch M, Schmitz A, Lassahn PG, Mevissen M, Thormann W.CE with multiple isomer sulfated beta-CD as the chiral selector was assessed for the simultaneous analysis of the enantiomers of ketamine and metabolites in extracts of equine plasma and urine. Different lots of the commercial chiral selector provided significant changes in enantiomeric ketamine separability, a fact that can be related to the manufacturing variability. A mixture of two lots was found to provide high-resolution separations and interference-free detection of the enantiomers of ketamine, norketamine, dehydronorketamine, and an incompletely identified hydroxylated metabolite of no...
Yamada M, Aramaki S, Okayasu T, Hosoe T, Kurosawa M, Kijima-Suda I, Saito K, Nakazawa H.Anabolic steroids with the 17alpha-methyl,17beta-hydroxyl group, which were developed as oral formulations for therapeutic purposes, have been abused in the field of human sports. These anabolic steroids are also used to enhance racing performance in racehorses. In humans, structurally related 17alpha-methyltestosterone (MTS) and mestanolone (MSL), which are anabolic steroids with the 17alpha-methyl,17beta-hydroxyl group, have metabolites in common. The purpose of this study was to determine metabolites common to these two steroids in horses, which may serve as readily available screening targ...
Duggan VE, Holyoak GR, MacAllister CG, Cooper SR, Confer AW.The objective of this study was to investigate the protein, amyloid A3 (AA3), in equine colostrum and early milk. We hypothesized that AA3 was consistently present in equine colostrum and early milk, that no correlation existed between serum and colostrum concentrations of this protein in individual mares at parturition and that colostrum/milk concentrations of this mammary protein may be affected by age, breed, length of gestation and/or induction of parturition. Thirty-eight peripartum mares and seven non-pregnant, non-lactating mares were included in the study. Mean serum concentrations of ...
Allsopp MT, Lewis BD, Penzhorn BL.The intra-erythrocytic parasite Theileria equi is one of two tick-transmitted causative agents of equine piroplasmosis. Piroplasms of T. equi can be transmitted across the equine placenta and once a horse is infected, it appears to remain a lifelong carrier, since anti-theilerial drugs suppress but do not eliminate the parasite. Carrier mares may transmit the organism to their offspring and this may result in abortion or neonatal piroplasmosis, but observations by some researchers suggest that foals may be born as carriers yet remain apparently healthy. Using a T. equi-specific oligonucleotide...
Hendrickson DA.Equine surgery continues to benefit from advances in endoscopic surgical techniques. Much of what we have learned in equine endoscopy comes from techniques used in humans. Descriptions of the normal anatomy of the standing horse and advances in instrumentation have improved our ability to perform laparoscopic surgery in standing and dorsally recumbent horses. This article describes the history of laparoscopy and available instrumentation.
Li X, Morris LH, Allen WR.This study investigated the basic conditions required for the production of horse embryos by the transfer of the nuclei of fetal and adult fibroblast cells to enucleated oocytes. Cumulus-oocyte complexes were recovered from abattoir ovaries and matured in vitro in groups of 20-30 for 28-30 h in tissue culture medium 199 containing 20% v:v fetal bovine serum in coculture with equine oviduct epithelial cells. Fetal fibroblast cells (FFC) were derived from a 32-day-old Thoroughbred x Pony fetus, and adult skin fibroblast cells (SFC) were obtained from subdermal biopsies recovered from a 4-yr-old ...
Laut JE, Houpt KA, Hintz HF, Houpt TR.In order to determine if horses will increase their intake in response to caloric dilution, four pony geldings were fed ad lib a mixed grain diet either undiluted (3.4 Mcal/kg of digestible energy) or diluted (wt/wt) with 25% sawdust (2.6 Mcal/kg) or with 50% sawdust (1.7 Mcal/kg). The mean daily caloric intake was 17,457 kcal (3.4 Mcal diet), 17,546 kcal (2.6 Mcal diet) and 12,844 kcal (1.7 Mcal). The mean time spent eating was 246 (3.4 Mcal), 351 (2.6 Mcal), and 408 (1.7 Mcal) minutes/day. Meal size increased and meal frequency decreased with increasing dilution. The median long survivorship...
Barr AR, Dow SM, Goodship AE.Recordings of forelimb ground reaction forces were made from 48 normal ponies moving at the trot, to evaluate the relationships between bodyweight, vertical ground reaction forces, the timing of individual events within the stance phase and the total contact time. There were highly significant correlations between the mean vertical ground reaction forces and bodyweight. The mean vertical ground reaction forces, corrected for bodyweight, were inversely correlated with the total contact time suggesting that higher trotting speeds may be associated with greater vertical ground reaction forces. Th...
Krueger AS, Kinden DA, Garner HE, Sprouse RF.The morphologic and pathologic changes which occurred within the cecal mucosa of 4 horses during the onset of laminitis were determined from cecal biopsy materials obtained via a cecal fistula; the laminitis was induced with carbohydrate overload. The cecal epithelial mucosa specimens were obtained at 0 (base line), 24, 32, 48, and 72 hours after horses were given carbohydrate overload, and these were fixed and subsequently photographed. Changes in the cecal epithelium were examined by transmission electron and scanning electron microscopies. These histopathologic changes indicated that the mu...
Bergsten G, Holmbäck R, Lindberg P.Blood Se of adult horses was 26.1, 25.8, and 27.0 ng/ml (mean values at 3 farms), where the Se of food was about 20 ng/g dry substance. Experimental adult horses which received about 41 ng Se/g food showed 45.3 ng/ml blood. At low Se intake suckling foals show higher blood Se than mares, but with high Se intake, the opposite will occur. This is reflected in milk Se, which raises but slowly with rise of mare’s blood Se. Se in blood plasma and in blood corpuscles is on the same level. The effect of various dose levels of Se on blood Se was studied: From 1.5 to 6 mg Se/week, blood Se rose rathe...
Bigley RF, Gibeling JC, Stover SM, Hazelwood SJ, Fyhrie DP, Martin RB.Volume effects are a fundamental determinant of structural failure. A material exhibits a volume effect if its failure properties are dependent on the specimen volume. Many brittle ceramics exhibit volume effects due to loading a structure in the presence of "critical" flaws. The number of flaws, their locations, and the effect of stress field within the stressed volume play a role in determining the structure's failure properties. Since real materials are imperfect, structures composed of large volumes of material have higher probabilities of containing a flaw than do small volumes. Consequen...
Pennington PM, Splan RK, Jacobs RD, Wang Y, Wagner AL, Freeman EW, Pukazhenthi BS.The reproductive cycle and early pregnancy represent dynamic physiological states in mammals, but mechanisms involved in early pregnancy in the domestic horse remain poorly understood. Proteins in uterine secretions have been studied, but the proteome of peripheral serum during various reproductive states has not been investigated. This study characterized and compared the serum proteome in the domestic horse during various reproductive states. Serum was collected from three mares during: (1) estrus (day [d] -1; d 0 = ovulation), (2) diestrus (d 12.5, non-mated), (3) early pregnancy (d 12.5,...
Silva ILS, Junqueira GSB, Oliveira CAA, Costa RB, DE Camargo GMF.Grullo is a dun dilution on a black coat that is common in the Campolina horse: an autochthonous Brazilian breed. The aims of this case study were to evaluate inconsistencies in grullo coat color registration and to explain their possible causes. A total of 3,270 grullo Campolina horses were evaluated. To confirm the genetic possibility of having grullo animals, the coat color genotypes of parents were inferred by phenotype and compared with those of progeny. A total of 242 horses that were registered as grullos could not have this coat based on their parents' information. Possible explanation...
Quinlan TJ, Goulden BE, Barnes GR, Anderson LJ, Cahill JI.The nerve supply to the intrinsic laryngeal muscles of the horse was studied by gross dissection and by electromyography which was carried out before, during and after section of various intralaryngeal nerve branches. The anatomical relationships and passage of the laryngeal nerves throughout the larynx were defined. Unlike the dog and man there was no evidence of the passage of motor nerve fibres from one side of the larynx to the other.
Vizcarra JA, Ford JJ.The sperm mobility assay used in the present study measures the rate of sperm penetration in a biologically inert cell-separation solution (Accudenz). When a sample of sperm is overlaid in a cuvette containing Accudenz, sperm penetrate the solution and absorbance of the sample can be measured with a spectrophotometer. This assay has been successfully used to select chicken and turkey semen donors. We validated this assay for semen from boars and stallions. Absorbance was measured after overlaying fresh semen from each species in prefilled cuvettes for 1, 5, 10, 15, 20, and 40 min. There were n...
Li CH, Chung D.Isolation of prolactin from equine pituitary glands has been described. It has a potency of 42 IU/mg in the pigeon crop-sac test and consists of 199 amino acids. The hormone has only four half-cystine residues in contrast to other mammalian prolactins which have six residues. From NH2-terminal sequence analysis and amino acid composition of cyanogen bromide fragments, the NH2-terminal disulfide loop is missing in the equine prolactin molecule. Circular dichroism spectra indicate that the alpha-helical content of equine prolactin appears to be lower (50%) than that found in the ovine hormone (6...
McDonnell SM, Hinze AL.Periodic spontaneous erection and penile movements known as masturbation (SEAM) occur normally at approximately 90 min intervals in awake equids. SEAM in horses has traditionally been misunderstood by many horsemen as aberrant behavior that should be eliminated. Accordingly, it is not uncommon for trainers of performance stallions or managers of breeding stallions to punish SEAM in an attempt to eliminate the behavior. Previous clinical observations and preliminary unsystematic trials had suggested that attempts to stop stallion SEAM may lead to an increase rather than a decrease in SEAM, and ...
Malekipour F, Oetomo D, Lee PV.Subchondral bone microdamage due to high-impact loading is a key factor leading to post-traumatic knee osteoarthritis. A quantified assessment of the mechanical characteristics of subchondral bone at the tissue-level is essential to study the mechanism of impact-induced microdamage. We combined mechanical impact testing of equine cartilage-bone with µCT image-based finite element models (μFEM) of each specimen to determine subchondral bone (including calcified cartilage: CCSB) elastic tissue modulus and local stresses and strains associated with micro-fractures within the CCSB tissue. The ma...
Bronstein A, Marx A.Comparison of myoglobin structures reveals that protein isolated from horse heart consistently adopts an alternate turn conformation in comparison to its homologues. Analysis of hundreds of high-resolution structures discounts crystallization conditions or the surrounding amino acid protein environment as explaining this difference, that is also not captured by the AlphaFold prediction. Rather, a water molecule is identified as stabilizing the conformation in the horse heart structure, which immediately reverts to the whale conformation in molecular dynamics simulations excluding that structur...