The physiology of horses encompasses the study of the biological functions and processes that occur within the equine body. This includes the examination of various systems such as the cardiovascular, respiratory, musculoskeletal, digestive, and nervous systems. Understanding equine physiology is essential for comprehending how horses adapt to different environmental conditions, perform physical activities, and respond to health challenges. Research in this field often focuses on the mechanisms of energy metabolism, thermoregulation, and muscle function during exercise, as well as the physiological responses to stress and disease. This page compiles peer-reviewed research studies and scholarly articles that explore the diverse aspects of equine physiology, providing insights into the biological processes that support the health and performance of horses.
Harlow BE, Lawrence LM, Kagan IA, Flythe MD.The goals of this study were to determine if β-acid from hops (Humulus lupulus L.) could be used to control fructan fermentation by equine hindgut micro-organisms, and to verify the antimicrobial mode of action on Streptococcus bovis, which has been implicated in fructan fermentation, hindgut acidosis and pasture-associated laminitis (PAL) in the horse. Results: Suspensions of uncultivated equine faecal micro-organisms produced fermentation acids when inulin (model fructan) was the substrate, but β-acid (i.e. lupulone) concentrations ≥9 ppm inhibited lactate production and mitigated the d...
Underwood C, Collins SN, van Eps AW, Allavena RE, Medina-Torres CE, Pollitt CC.There are no experimentally validated pharmacological means of preventing laminitis; however, locally acting pharmaceutical agents with the potential to prevent laminitis have been identified. Demonstrating therapeutic drug concentrations in lamellar tissue is essential for evaluating the efficacy of these agents. The aim of this study was to develop an experimental technique for repeatedly sampling lamellar interstitial fluid. A technique for placing ultrafiltration probes was developed in vitro using 15 cadaver limbs. Subsequently, lamellar ultrafiltration probes were placed in one forelimb ...
Hubbell JA, Muir WW.Horses are the most difficult of the common companion animals to anaesthetise. Hypoxaemia or inadequate oxygen delivery to peripheral tissues during anaesthesia would seem a potential cause of increased mortality, but no direct link has been established. A number of methods of increasing oxygenation and oxygen delivery have been reported, with varying results and potential applicability. The purpose of this article is to review the literature with regard to oxygenation, oxygen delivery and methods to improve each and to make recommendations for clinical application.
Cecchini S, Paciolla M, Caputo AR, Bavoso A.In order to counteract harmful effects of oxidative stress due to pathological conditions or physical exercise, horses are often administered dietary supplements having supposed high antioxidant activities. The aim of the present study was to identify the in vitro antioxidant potential of "ImmuPlus", a polyherbal formulation (Global Herbs LTD, Chichester, West Sussex, Great Britain), containing three medicinal plants (Withania somnifera, Tinospora cordifolia, and Emblica officinalis), known in Ayurveda for their use in human disease treatment. Extracts obtained by different solvents (water, me...
Stine JM, Michau TM, Williams MK, Kuebelbeck KL, Stengard ME.Original study. Objective: To evaluate the effect of sedation with romifidine hydrochloride 1% (Sedivet: Boehringer-Ingelheim) on intraocular pressure (IOP) in the normal horse and horses with incidental ophthalmic findings as measured by applanation tonometry. Methods: Nineteen clinically normal horses (13 geldings, six mares) and eight horses (three geldings, five mares) with incidental ophthalmic findings were included in this study. Methods: All horses underwent complete ophthalmic examination with pharmacologic mydriasis a minimum of 2 weeks prior to IOP evaluation. Baseline intraocular p...
Sheats MK, Pescosolido KC, Hefner EM, Sung EJ, Adler KB, Jones SL.Neutrophil infiltration is a prominent feature in a number of pathologic conditions affecting horses including recurrent airway obstruction, ischemia-reperfusion injury, and laminitis. Cell signaling components involved in neutrophil migration represent targets for novel anti-inflammatory therapies. In order to migrate into tissue, neutrophils must respond to chemoattractant signals in their external environment through activation of adhesion receptors (i.e. integrins) and reorganization of the actin cytoskeleton. Myristoylated Alanine-Rich C-Kinase Substrate (MARCKS), a highly conserved actin...
De Sordi N, Bombardi C, Chiocchetti R, Clavenzani P, Trerè C, Canova M, Grandis A.The objective of the present study was to verify if polyurethane foam is a suitable material to make accurate casts of vessels and viscera, and to develop a method based on its use for anatomical studies. This new technique has been tested primarily on the lungs of different animals, but also on the renal, intestinal and equine digital vessels. It consisted of three steps: specimen preparation, injection of the foam and corrosion of the cast. All structures injected with foam were properly filled. The bronchial tree and the vessels could be observed up to their finer branches. The method is in...
Furukawa S, Kuroda Y, Sugiyama A.The primary function of the placenta is to act as an interface between the dam and fetus. The anatomic structure of the chorioallantoic placenta in eutherian mammals varies between different animal species. The placental types in eutherian mammals are classified from various standpoints based on the gross shape, the histological structure of the materno-fetal interface, the type of materno-fetal interdigitation, etc. Particularly, the histological structure is generally considered one of the most useful and instructive classifications for functionally describing placental type. In this system,...
Rodrigues MN, Carvalho RC, Franciolli AL, Rodrigues RF, Rigoglio NN, Jacob JC, Gastal EL, Miglino MA.Since the horse has a highly precocial reproductive strategy, most organs are functionally well developed at birth and thus, embryonic and fetal life is interesting. Data on the development of important organs are very limited. Here, we detailed macroscopically and histologically the equine digestive system, focusing on the first third of gestation. At 21 days, the oral cavity was an empty space, and the liver contained proliferating endodermal cells. At 25 days, a fusiform stomach and the pancreatic bud were present. At 28 days, a small tongue and the esophagus occurred. At 30 days, primary a...
Bujacz A, Zielinski K, Sekula B.Serum albumin, a protein naturally abundant in blood plasma, shows remarkable ligand binding properties of numerous endogenous and exogenous compounds. Most of serum albumin binding sites are able to interact with more than one class of ligands. Determining the protein-ligand interactions among mammalian serum albumins is essential for understanding the complexity of this transporter. We present three crystal structures of serum albumins in complexes with naproxen (NPS): bovine (BSA-NPS), equine (ESA-NPS), and leporine (LSA-NPS) determined to 2.58 Å (C2), 2.42 Å (P61), and 2.73 Å (P2₁2₁...
Sayasith K, Sirois J.The interaction between stromal cell-derived factor-1 (SDF1) and chemokine CXC motif receptor 4 (CXCR4) has been implicated in leukocyte attraction, tissue remodeling and angiogenesis. The objective of the present study was to characterize the expression and regulation of SDF1 and CXCR4 in equine follicles during the ovulatory process. Equine preovulatory follicles were isolated during estrus 0-39h after hCG treatment. Follicle wall preparations (theca interna with attached granulosa cells) and isolated preparations of granulosa cells and theca interna were obtained, and total RNA extracts wer...
Gaivão MM, Rambags BP, Stout TA.Experimental studies and field surveys suggest that embryonic loss during the first 6 weeks of gestation is a common occurrence in the mare. During the first 2 weeks of development, a number of important cell differentiation events must occur to yield a viable embryo proper containing all three major germ layers (ectoderm, mesoderm, and endoderm). Because formation of the mesoderm and primitive streak are critical to the development of the embryo proper, but have not been described extensively in the horse, we examined tissue development and differentiation in early horse conceptuses using a c...
Ing NH, Forrest DW, Love CC, Varner DD.Stallions are unique among livestock in that, like men, they commonly receive medical treatment for subfertility. In both species, about 15% of individuals have normal semen parameters but are subfertile, indicating a need for novel analyses of spermatozoa function. One procedure for improving fertilizing capability of stallions and men is isolation of dense spermatozoa from an ejaculate for use in artificial insemination. In the current study, dense and less dense spermatozoa were purified by density gradient centrifugation from individual ejaculates from seven reproductively normal adult sta...
Santos MP, Gutierrez-Nibeyro SD, Horn GP, Johnson AJ, Stewart MC, Schaeffer DJ.To compare the mechanical properties of laryngeal tie-forward (LTF) surrogate constructs prepared with steel fixtures and No. 5 braided polyester or braided polyethylene by use of a standard or a modified suture placement technique. Methods: 32 LTF surrogate constructs. Methods: Surrogate constructs were prepared with steel fixtures and sutures (polyester or polyethylene) by use of a standard or modified suture placement technique. Constructs underwent single-load-to-failure testing. Maximal load at failure, elongation at failure, stiffness, and suture breakage sites were compared among constr...
Beckwith-Cohen B, Elad D, Bdolah-Abram T, Ofri R.To determine baseline tear pH in dogs, horses, and cattle by use of a microelectrode. Methods: 28 dogs, 24 horses, and 29 cattle. Methods: Under manual restraint, tears were collected from each subject's left eye with cotton spears. A Schirmer tear test was performed in the right eye. Tears were extracted from the spears by centrifugation. Tear volume was measured, pH was determined with a microelectrode, and total solids (TS) concentration was measured by refractometry. Results: Mean ± SD pH of tears in cattle, dogs, and horses was 8.32 ± 0.14, 8.05 ± 0.26, and 7.84 ± 0.30, respectively. ...
de Oliveira FS.Anatomical specimens used in human or veterinary anatomy laboratories are usually prepared with formaldehyde (a cancerous and teratogenic substance), glycerin (an expensive and viscous fluid), or ethanol (which is flammable). This research aimed to verify the viability of an aqueous 30% sodium chloride solution for preservation of anatomical specimens previously fixed with formaldehyde. Anatomical specimens of ruminant, carnivorous, equine, swine and birds were used. All were previously fixed with an aqueous 20% formaldehyde solution and held for 7 days in a 10% aqueous solution of the same ...
Menzies-Gow NJ, Wray H, Bailey SR, Harris PA, Elliott J.Insulin and inflammatory cytokines may be involved in equine laminitis, which might be associated with digital vascular dysfunction. This study determined the effects of TNF-α and insulin on the endothelial-dependent relaxant responses of equine digital blood vessels and on equine digital vein endothelial cell (EDVEC) cGMP production. Methods: Isolated rings of equine digital arteries (EDAs) and veins (EDVs) were obtained and EDVECs were cultured from horses euthanized at an abattoir. Methods: The effect of incubation with TNF-α (10 ng/ml) and/or insulin (1,000 μIU/ml) for 1.5 h or overn...
Ayo JO, Dzenda T, Olaifa F, Ake SA, Sani I.The study was designed to determine diurnal and seasonal changes in basic physiologic responses of donkeys adapted to the tropical Savannah. The rectal temperature (RT), respiratory rate (RR) and heart rate (HR) of six male Nubian pack donkeys, and the dry-bulb temperature (DBT), relative humidity and heat index of the experimental site were concurrently recorded hourly, from 06:00 h to 18:00 h (GMT +1), for three days, spread 1 week apart, during the cold-dry (harmattan), hot-dry and humid (rainy) seasons, in an open grazing field. Values of the physiologic parameters recorded during the morn...
Barsby T, Bavin EP, Guest DJ.The natural reparative mechanisms triggered by tendon damage often lead to the formation of biomechanically inferior scar tissue that is prone to re-injury. Before the efficient application of stem cell-based regenerative therapies, the processes regulating tenocyte differentiation should first be better understood. Three-dimensional (3D) growth environments under strain and the exogenous addition of transforming growth factor beta3 (TGF-β3) have separately been shown to promote tendon differentiation. The aim of this study was to determine the ability of both of these factors to induce tendo...
Burns TA, Watts MR, Weber PS, McCutcheon LJ, Geor RJ, Belknap JK.In EMS-associated laminitis, laminar failure may occur in response to energy failure related to insulin resistance (IR) or to the effect of hyperinsulinemia on laminar tissue. 5'-Adenosine-monophosphate-activated protein kinase (AMPK) is a marker of tissue energy deprivation, which may occur in IR. Objective: To characterize tissue AMPK regulation in ponies subjected to a dietary carbohydrate (CHO) challenge. Methods: Twenty-two mixed-breed ponies. Methods: Immunohistochemistry and immunoblotting for total AMPK and phospho(P)-AMPK and RT-qPCR for AMPK-responsive genes were performed on laminar...
Mangal D, Uboh CE, Soma LR, Liu Y.Glucocorticoids (corticosteroids) are widely used anti-inflammatory agents in veterinary medical practice. These drugs are considered doping agents because they mask pain and thus, increase injury potential in equine athletes. They exhibit anti-inflammatory property by binding to glucocorticoids receptor (GR) to control the transcription of pro- and anti-inflammatory cytokines and enzymes involved in the synthesis of bioactive eicosanoids. To evaluate the role of triamcinolone acetonide (TA) on concentrations of bioactive eicosanoids in equine plasma, TA (0.04 mg/kg) was intravenously administ...
Curtis S, Martin J, Hobbs S.A circumferential ring in the hoof horn of foals occurs at birth and grows down to the distal border as the fetal hoof is replaced. Horn growth and complete hoof capsule renewal have not been measured in Thoroughbred foals but the determination of time of hoof renewal may allow accurate predictions of healing time to be made in cases of hoof lesions. The objective of this study was to measure the time taken for the fetal hoof of newborn foals to grow to the distal border and be replaced by hoof grown since birth. The age of the foal in days on the day that routine hoof trimming removed the hoo...
Warnock JJ, Fox DB, Stoker AM, Beatty M, Cockrell M, Janicek JC, Cook JL.Introduction. Tissue engineering is a new methodology for addressing meniscal injury or loss. Synovium may be an ideal source of cells for in vitro meniscal fibrocartilage formation, however, favorable in vitro culture conditions for synovium must be established in order to achieve this goal. The objective of this study was to determine cellularity, cell distribution, and extracellular matrix (ECM) formation of equine fibroblast-like synoviocytes (FLS) cultured on synthetic scaffolds, for potential application in synovium-based meniscal tissue engineering. Scaffolds included open-cell poly-L-l...
Moens Y, Schramel JP, Tusman G, Ambrisko TD, Solà J, Brunner JX, Kowalczyk L, Böhm SH.The use of alveolar recruitment maneuvers during general anaesthesia of horses is a potentially useful therapeutic option for the ventilatory management. While the routine application of recruitments would benefit from the availability of dedicated large animal ventilators their impact on ventilation and perfusion in the horse is not yet well documented nor completely understood. Methods: A healthy 533 kg experimental horse underwent general anaesthesia in lateral recumbency. During intermittent positive pressure ventilation a stepwise alveolar recruitment maneuver was performed. Results: Anae...
Sessions-Bresnahan DR, Graham JK, Carnevale EM.IVF in horses is rarely successful. One reason for this could be the failure of sperm to fully capacitate or exhibit hyperactive motility. We hypothesized that the zona pellucida (ZP) of equine oocytes prevents fertilization in vitro, and bypassing the ZP would increase fertilization rates. Limited availability of equine oocytes for research has necessitated the use of heterologous oocyte binding assays using bovine oocytes. We sought to validate an assay using bovine oocytes and equine sperm and then to demonstrate that bypassing the ZP using perivitelline sperm injections (PVIs) with equine ...
Pilarczyk B, Tomza-Marciniak A, Stankiewicz T, Błaszczyk B, Gaczarzewicz D, Smugała M, Udała J, Tylkowska A, Kuba J, Cieśla A.The aim of this study was to determine serum selenium concentrations in Polish Konik horses residing in the Odra Delta Nature Park (Poland) and to evaluate the activity of glutathione peroxidase and Se content in testes of this horse breed. In over 95% of cases, serum Se concentration was below the optimal range, and none of the horses examined was deficient in this trace element. The lack of Se deficiency in the animals examined suggests however, that the Polish Konik horses have a natural ability to the optimal use of nutrients available in their life area. Testicular content of Se and GSHPx...
Williams ZJ, Velez-Irizarry D, Petersen JL, Ochala J, Finno CJ, Valberg SJ.Myofibrillar myopathy (MFM) of unknown aetiology has recently been identified in Warmblood (WB) horses. In humans, 16 genes have been implicated in various MFM-like disorders. Objective: To identify variants in 16 MFM candidate genes and compare allele frequencies of all variants between MFM WB and non-MFM WB and coding variants with moderate or severe predicted effects in MFM WB with publicly available data of other breeds. To compare differential gene expression and muscle fibre contractile force between MFM and non-MFM WB. Methods: Case-control. Methods: 8 MFM WB, 8 non-MFM WB, 33 other WB,...
Naden J, Amann RP, Squires EL.Puberty was studied using 15 colts of Quarter Horse phenotype. Total scrotal width was measured every 8 weeks from 48 to 96 weeks. Blood samples were taken from 8 colts at 8, 16 and 24 weeks and then every 4 weeks until 100 weeks to measure changes in LH, FSH and testosterone concentrations. Seminal collections were attempted monthly from 48 to 64 weeks and every 2 weeks thereafter until puberty resumed every 3rd day from 96 weeks for 15 ejaculates. For all collections, times to erection, mount and ejaculation and seminal characteristics were recorded. Age at puberty was defined as the first e...
Tamanini C, Giordano N, Chiesa F, Seren E.Plasma cortisol variations have been determined by radioimmunoassay in 5 stallions during mating and in 2 teasers during oestrous female exposure. In all the animals, cortisol plasma levels consistently increase (71.1 ng/ml vs 44.0 and 63.0 ng/ml vs 35.1, in the stallions and in the teasers, respectively) 7-30 min after female exposure; 120 min after exposure, cortisol concentrations are again low.
Ortiz I, Dorado J, Ramírez L, Morrell JM, Acha D, Urbano M, Gálvez MJ, Carrasco JJ, Gómez-Arrones V, Calero-Carretero R, Hidalgo M.The aim of this study was to determine the effect of single layer centrifugation (SLC) using Androcoll-E-Large on donkey sperm quality parameters after 24 h of cool-storage. Ejaculates were collected from Andalusian donkeys and then cooled at 5°C. SLC was carried out after 24 h of cool-storage using Androcoll-E-Large. In the first experiment, all sperm parameters assessed (total and progressive sperm motility, viability, sperm morphology and sperm kinematics VCL, VSL, VAP, LIN, STR, WOB, ALH and BCF) were statistically compared between semen samples processed or not with Androcoll-E-Large. Si...
Cheng R, McKibbin L, Roy B, Pomeranz B.It was hypothesized that electroacupuncture releases beta-endorphin and ACTH from the pituitary. Since ACTH induces the release of cortisol from the adrenal glands, blood cortisol level should be enhanced by electroacupuncture. The present result shows that the blood cortisol levels of horses are significantly increased after 30 min of electroacupuncture treatment while the sham treatment (control) shows an insignificant effect.
Kang H, Zsoldos RR, Woldeyohannes SM, Gaughan JB, Sole Guitart A.Accurately measuring body temperature in horses will improve the management of horses suffering from or being at risk of developing postrace exertional heat illness. PTSM has the potential for measuring body temperature accurately, safely, rapidly, and noninvasively. This study was undertaken to investigate the relation between the core body temperature and PTSM temperatures prior to, during, and immediately after exercise. The microchips were implanted into the nuchal ligament, the right splenius, gluteal, and pectoral muscles, and these locations were then compared with the central venous te...
Bertelsmann H, Keppler S, Höltershinken M, Bollwein H, Behne D, Alber D, Bukalis G, Kyriakopoulos A, Sieme H.The essential trace element selenium is indispensable for male fertility in mammals. Until now, little data existed regarding the relationship between selenium and sperm quality in the stallion. Selenium, or selenium-dependent glutathione peroxidase activity, was determined in red blood cells, semen, seminal plasma and spermatozoa, and the percentages of spermatozoa with progressive motility (PMS), intact membranes (PMI), altered (positive) acrosomal status (PAS) and detectable DNA damage, determined by the sperm chromatin structure assay, were evaluated in 41 healthy stallions (three samples ...
Thomason JJ, McClinchey HL, Jofriet JC.Finite-element (FE) methods have great potential in equine biomechanics in evaluating mechanical stresses and strains in tissues deep within the hoof. In this study, we critically assessed that potential by comparing results of FE analyses of capsular strain with in vivo data. Nine FE models were developed, corresponding to the shape of hooves for which in vivo principal strain data are available. Each model had the wall, laminar junction, sole and distal phalanx (PIII). In a first loading condition (LC1), force is distributed uniformly to the bearing surface of the wall to determine reaction ...
Snow DH, Guy PS.The use of the technique of percutaneous needle biopsy in obtaining skeletal muscle samples in the horse is described. The biochemical, ultrastructural and histochemical investigations that can be carried out on this biopsy specimen are outlined. Analyses performed on the specimen may be used to obtain information on racing potential and state of fitness. These studies on normal horses will provide information for future investigations into the structural and biochemical alterations in muscle disorders in the equine.
Clément F, Barrey E.Variability of heart rate was analysed within a sample of 30 horses in order to determine the influence of factors (animal, age, sex and breed) associated with different behavioural patterns. The heart rate fluctuations were analysed by computing the power spectral density of a series of heartbeat intervals. A generalized linear model was used to compare the spectra and to reveal the effect of each factor: animal age, sex and breed. The scale and shape of spectral densities were significantly different between animals. This individual variability was partly explained by the sex and age effects...
Allen PZ, Dalton EJ.Donkey IgGa was isolated in purified form from normal and immune donkey sera by column chromatography on DEAE-cellulose. Isolated donkey IgGa and mixtures of (IgGa+IgGb) were used as antigens to prepare rabbit reagents specific for equine IgGa or IgGb. Antibodies present in sera obtained from a single donkey at various times during the course of hyperimmunization with BSA were isolated by immuno-adsorption. The class or subclass of immunoglobulins present among isolated, donkey anti-BSA antibodies was determined by use of specific rabbit anti-equine immunoglobulin reagents. The homologues of h...
Squires EL, Pickett BW, Amann RP.Five ejaculates were collected at hourly intervals from 32 sexually rested stallions. Gel volume, total seminal volume, sperm concentration and spermatozoa per ejaculate declined (P less than 0.01) from the first to the second or third ejaculate. Gel-free seminal volume or percentage of motile spermatozoa did not vary (P less than 0.05) among ejaculates. Ejaculates from 2- to 3-year-old stallions contained less volume and fewer spermatozoa than those from 9- to 16-year-old stallions. Regardless of the stallion's age the first, first 2, first 3 and first 4 ejaculates represented 50, 74, 86 and ...
Pérez Manrique L, Hudson R, Bánszegi O, Szenczi P.The study of individual differences in behavior and physiology has attracted considerable interest among behavioral biologists. Important questions include how early in life such differences emerge and to what extent they remain stable across development. Due to the demanding nature of longitudinal studies, there is still a lack of information on this in mammals, especially in large, long-lived species. Our aim in this study was to look for stable individual differences in behavior and physiology during early development in the domestic horse and for correlations between the two parameters. We...
Rogers CW, Back W.To quantify the effect of plain, wedged and eggbar shoes on the distribution of pressure under the hoof of horses at the walk, at selected areas of interest (AOI), to find scientific evidence for the perceived efficacy of these shoes in the treatment of palmar heel pain. Methods: Six clinically sound adult Warmblood mares weighing 551 (SD 25) kg were shod (forelegs) with either plain, eggbar or 6 degrees-wedge shoes using a latin-square experimental design. All horses were shod by the same farrier, and each balanced and aligned for its individual conformation. Data were collected on three walk...
Sengupta ME, Thapa S, Thamsborg SM, Mejer H.Strongyle eggs of helminths of livestock usually hatch within a few hours or days after deposition with faeces. This poses a problem when faecal sampling is performed in the field. As oxygen is needed for embryonic development, it is recommended to reduce air supply during transport and refrigerate. The present study therefore investigated the combined effect of vacuum packing and temperature on survival of strongyle eggs and their subsequent ability to hatch and develop into L3. Fresh faecal samples were collected from calves infected with Cooperia oncophora, pigs infected with Oesophagostomu...
McCrae P, Spong H, Golestani N, Mahnam A, Bashura Y, Pearson W.Electrocardiograms (ECGs), and associated heart rate (HR) and heart rate variability (HRV) measurements, are essential in assessing equine cardiovascular health and fitness. Smart textiles have gained popularity, but limited validation work has been conducted. Therefore, the objective of this study was to compare HR and HRV data obtained using a smart textile system (Myant) to the gold-standard telemetric device (Televet). Simultaneous ECGs were obtained using both systems in seven horses at rest and during a submaximal exercise test. Bland-Altman tests were used to assess agreement between th...
Bliss SB, Voge JL, Hayden SS, Teague SR, Brinsko SP, Love CC, Blanchard TL, Varner DD.The objective was to determine if decreased cushion-fluid volume and increased sperm number during centrifugation, or if sperm concentration of extended semen following centrifugation, affected stallion sperm quality. Three ejaculates from each of three stallions were subjected to cushioned centrifugation (1,000g for 20 min). Cushion-fluid volume was set at 1 or 3.5 ml, and sperm number per centrifuge tube was set 1 billion or 3 billion. Following centrifugation, sperm pellets were resuspended in semen extender containing 20% seminal plasma (v/v) with sperm concentrations of 25 or 250 million/...
Park JW, Choi JY, Hong SA, Kim NY, Do KT, Song KD, Cho BW.This study was performed to reveal the molecular structure and expression patterns of horse glutamate-cysteine ligase catalytic subunit () and glutamate-cysteine ligase modifier subunit () genes whose products form glutamate cysteine ligase, which were identified as differentially expressed genes in the previous study. Methods: We performed bioinformatics analyses, and gene expression assay with quantitative polymerase chain reaction (qPCR) for horse and genes in muscle and blood leukocytes of Thoroughbred horses. Results: Expression of showed the same pattern in both blood and muscle tissu...
Macuda T, Timney B.Equine colour vision was measured under conditions that minimised the possibility of animals using brightness cues to make chromatic discriminations. In a two-stage study, we first obtained luminance discrimination functions for achromatic targets then tested for chromatic discrimination over a range of target luminances. Horses were trained on a two-choice discrimination task. The positive stimulus was varied in luminance and/or colour using neutral density and broad band colour filters. The negative stimulus appeared as a uniform grey. In the brightness discrimination task, the horses perfor...
Moore RM, Hardy J, Muir WW.Six horses were subjected to 3 hours of low-flow ischemia and 3 hours of reperfusion of the large colon. After induction of anesthesia, the large colon was exteriorized through a ventral midline celiotomy. Colonic blood flow was measured continuously, using Doppler ultrasonic flow probes placed on the colonic arteries supplying the dorsal and ventral colons and was allowed to stabilize for 15 to 30 minutes after instrumentation. Low-flow ischemia was induced by reducing colonic arterial blood flow to 20% of baseline (BL) flow. Colonic mucosal, seromuscular, and full-thickness blood flow were d...
Champion ZJ, Breier BH, Ewen WE, Tobin TT, Casey PJ.A survey of standardbred horses was conducted to build up a normal population profile for insulin like growth factor-I (IGF-I) concentrations in racing standardbreds and to ascertain how age, sex and geographic location affect IGF-I. Blood samples were drawn by jugular venepuncture from 202 racing standardbred horses aged one to eight years located in five different geographic regions of New Zealand. IGF-I concentrations were determined by insulin like growth factor-I binding protein (IGFBP)-blocked radioimmunoassay validated for the horse. As described in other species, age played a significa...
McGuigan MP, Wilson AM.Horses with navicular disease have an increased load on the navicular bone in early stance. This has been suggested to be a response to pain in the heel region. Seven horses with clinical, radiographic and scintigraphic signs of navicular disease underwent forceplate and kinematic analysis before and after desensitisation of the heel region with a bilateral palmar digital nerve block. The compressive force exerted on the navicular bone during stance, and stride kinematics, were determined in each state. After regional analgesia of the palmar digital nerves (PDNB) the compressive force on the n...
Sloet van Oldruitenborgh-Oosterbaan MM, Barneveld A.Six Dutch warmblood horses, ridden by an experienced rider, cantered 3320 m at a speed adapted to the individual horse's anaerobic threshold, under four different conditions: 1, on a firm shell track with the speed varying from 6.5 to 9.4 m/s; 2, on a horizontal treadmill at the same speeds and for the same duration as in test 1; 3, on a horizontal treadmill for the same duration as in tests 1 and 2, but at a 10 per cent higher speed; and 4, on a treadmill at the same speed and for the same duration as in test 1, but at an inclination of 1 to 2 per cent adjusted individually to obtain heart ra...
Hosaka Y, Teraoka H, Yamamoto E, Ueda H, Takehana K.The aim of the present study was to clarify the presence and determine the role of apoptosis in the degenerative process of the superficial digital flexor tendon (SDFT) in the horse. Samples were obtained from normal and inflamed SDFTs of horses. To detect apoptosis and to identify apoptotic cells, the samples were subjected to immunohistochemical labelling and Western blot analysis. Although a large number of cells in degenerate areas showed positive reactions with caspase-3 and single stranded DNA antibodies, cells in normal tendon samples showed very weak reactions. Excessive apoptosis was ...
Kareskoski AM, Reilas T, Andersson M, Katila T.With the aim of investigating properties of stallion seminal plasma to eventually improve semen-handling techniques, sperm motility and plasma membrane integrity were analysed in different fractions of the ejaculates after storage. Semen was collected using a computer-controlled automated phantom that separates the ejaculates into five successive cups. Samples containing seminal plasma and skim milk extender were compared with samples stored in skim milk extender after the removal of seminal plasma by centrifugation. Fractionated ejaculates were stored cooled for 24 h after dilution with exten...
