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.
Loux S, Robles M, Chavatte-Palmer P, de Mestre A.Development and the subsequent function of the fetal membranes of the equine placenta require both complex and precise regulation of gene expression. Advancements in recent years in bioinformatic techniques have allowed more extensive analyses into gene expression than ever before. This review starts by combining publically available transcriptomic data sets obtained from a range of embryonic, placental and maternal tissues, with previous knowledge of equine placental development and physiology, to gain insights into key gene families relevant to placentation in the horse. Covering the whole o...
Robles M, Loux S, de Mestre AM, Chavatte-Palmer P.Equine placental development is a long process with unique features. Implantation occurs around 40 days of gestation (dpo) with the presence of a transient invasive placenta from 25-35 to 100-120 dpo. The definitive, non-invasive placenta remains until term (330 days). This definitive placenta is diffuse and epitheliochorial, exchanging nutrients, gas and waste with the endometrium through microvilli, called microcotyledons. These are lined by an external layer of haemotrophic trophoblast. Moreover, histotrophic exchange remains active through the histotrophic trophoblast located along the are...
Lo Feudo CM, Stucchi L, Stancari G, Alberti E, Conturba B, Zucca E, Ferrucci F.Exercise-induced pulmonary hemorrhage (EIPH) is a condition affecting up to 95% of racehorses, diagnosed by detecting blood in the trachea after exercise and/or the presence of hemosiderophages in the bronchoalveolar lavage fluid (BALf). Although EIPH is commonly associated with poor performance, scientific evidence is scarce. The athletic capacity of racehorses can be quantified through some parameters obtained during an incremental treadmill test; in particular, the speed at a heart rate of 200 bpm (V200), and the speed (VLa4) and the heart rate (HRLa4) at which the blood lactate concentrati...
Pruß D, Oldenhof H, Wolkers WF, Sieme H.The aim of this study was to establish an alginate encapsulation procedure for stallion sperm, and investigate if sperm encapsulation enhances longevity during cold storage and survival after cryopreservation. First, biocompatibility of the compounds needed for encapsulation was tested and factors determining capsule structure were identified. Sperm encapsulation was realized either by depositing droplets (20 µL) of sperm solution supplemented with barium or calcium chloride (10 mM) in alginate solution (0.25%, w/v), or by adding sperm-alginate droplets in solution containing barium or calc...
de Faria DA, do Prado Paim T, Dos Santos CA, Paiva SR, Nogueira MB, McManus C.Since domestication, horse breeds have adapted to their environments and differentiated from one another. This paper uses two methods to detect selection signatures in 23 horse breeds, eight of which are Brazilian (610 animals), both cold-blooded and warm-blooded, from temperate and tropical regions. These animals were genotyped using the GGP Equine BeadChip and we analysed the data by Principal Component Analysis (PCA). The samples were separated into groups based on their geographical area of origin and PCA results studied. The genomic regions under selection were detected by hapFLK and PCAd...
Huricha , Kawai M, Ninomiya S.In this study, we investigated suckling behavior and the distance between a foal and its mare as indicators of foal growth in Hokkaido native horses (HKD) during the first 40 days of life. Direct observations were made of 22 mare and foal pairs from two consecutive days 1 and 2, 5 and 6, 10 and 11, 20 and 21, 30 and 31, and 40 and 41 after birth by focal animal sampling for 3 h per day. Suckling behavior was continuously recorded, along with the terminator. The distance between the foal and its mare was determined using the instantaneous sampling method (1 min), and the percentage was calc...
Tucker ML, Wilson DG, Reinink SK, Carmalt JL.To characterize the 3-D geometry of the equine larynx replicating laryngeal hemiplegia and 4 surgical interventions by use of CT under steady-state airflow conditions. Secondly, to use fluid mechanic principles of flow through a constriction to establish the relationship between measured airflow geometries with impedance for each surgical procedure. Methods: 10 cadaveric horse larynges. Methods: While CT scans were performed, inhalation during exercise conditions was replicated for each of the following 5 conditions: laryngeal hemiplegia, left laryngoplasty with ventriculocordectomy, left lary...
Muñoz KA, Szarek M, Manfredi JM, Robertson SA, Hubbell JA, Holcombe SJ.To determine the effects of intravenous ethyl pyruvate, an anti-inflammatory with putative benefits in horses with endotoxemia, on cardiopulmonary variables during anesthesia and the quality of anesthetic recovery. Methods: Randomized, crossover, blinded experimental design. Methods: A total of six healthy Standardbred geldings, aged 13 ± 3 years and weighing 507 ± 66 kg (mean ± standard deviation). Methods: Horses were anesthetized for approximately 90 minutes on two occasions with a minimum of 2 weeks apart using xylazine for sedation, ketamine and diazepam for induction, and isoflurane i...
Ginther OJ.Intrauterine mobility of the fetal-amniotic unit is unique in equids among domestic species. Intrinsic activity begins as head nods on ∼ Day 40 (Day 0 = ovulation) and by Day 60 has progressed into intermittent subtle to vigorous head, neck, limb, and body movements. On Days 60-100, fetal mobility is maximal with traveling of the fetal-amniotic unit throughout an allantoic pool that encompasses the uterine horns, and uterine body. The fetus may be entirely within one uterine horn with the horn entrance closed behind it, and then may work through the entrance into the uterine body. Mobility...
Darmani Kuhi H, Hossein-Zadeh NG, France J, López S.A better knowledge of the growth of horses can facilitate sounder intervention in their health control, nutrition and management. This study compared five growth functions with either diminishing returns (monomolecular and Michaelis-Menten) or asymptotic sigmoidal (Gompertz, Richards and Lopez) behavior for describing the growth curves of horses, based on the relationship between a given somatic growth trait (body weight, withers height, or body weight to withers height ratio) and age. Data used in this study were those available in the literature for quarter horse males and thoroughbred foals...
Henshall C, Randle H, Francis N, Freire R.Domestic horses are widely used for physically demanding activities but the effect of exercise on their learning abilities has not been explored. Horses are also frequently exposed to stressors that may affect their learning. Stress and exercise result in the release of glucocorticoids, noradrenaline and other neurotransmitters that can influence learning. It is not currently possible to directly measure concentrations of neurotransmitters in the brains of behaving horses, however the inference of neurobiological processes from peripheral markers have been widely used in studies of human cogni...
Kozłowska N, Wierzbicka M, Jasiński T, Domino M.The horse, as a flight animal with a survival strategy involving rapid escape from predators, is a natural-born athlete with enormous functional plasticity of the respiratory system. Any respiratory dysfunction can cause a decline in ventilation and gas exchange. Therefore, respiratory diseases often lead to exercise intolerance and poor performance. This is one of the most frequent problems encountered by equine internists. Routine techniques used to evaluate respiratory tract diseases include clinical examination, endoscopic examination, radiographic and ultrasonographic imaging, cytological...
Twele L, Neudeck S, Delarocque J, Verhaar N, Reiners J, Noll M, Tünsmeyer J, Kästner SBR.High-definition oscillometry (HDO) over the metatarsal artery (MA) in anaesthetised horses has not yet been evaluated. This study aimed to assess agreement between HDO and invasive blood pressure (IBP) at the metatarsal artery, and to evaluate compliance with the American College of Veterinary Internal Medicine (ACVIM) consensus guidelines. In this experimental study, 11 horses underwent general anaesthesia for an unrelated, terminal surgical trial. Instrumentation included an IBP catheter in one and an HDO cuff placed over the contralateral MA, as well as thermodilution catheters. Systolic ar...
Lawrence L.The National Research Council (NRC) published the Recommended Nutrient Allowances for Horses in 1949. The subsequent publication was renamed the Nutrient Requirements of Horses and the 6th revised edition was published in 2007. The document has increased in size and scope from the initial publication in 1949 that contained 29 pages to the most recent version with 341 pages. Several formats for expressing requirements (dietary concentrations or daily amounts) have been utilized. In addition, a variety of methods have been employed to determine the nutrient requirements of horses since 1949. Man...
Tucker L, Almeida D, Wendt-Hornickle E, Baldo CF, Allweiler S, Guedes AGP.Lower than expected arterial oxygen tension (PaO) continues to be an unresolved problem in equine anesthesia. The aim of this randomized, crossover, and prospective study using six adult horses is to determine if a 15° reverse Trendelenburg position (RTP) increases PaO during inhalation anesthesia. Under constant-dose isoflurane anesthesia, dorsally recumbent horses were positioned either horizontally (HP) or in a 15° RTP for 2 h. Lungs were mechanically ventilated (15 mL/kg, 6 breaths/min). Arterial carbon dioxide tension (PaCO), PaO, inspired oxygen fraction (FiO), and end-tidal carbon dio...
Moore T, Williams JM, Becerra-Rodriguez MA, Dunne M, Kammerer R, Dveksler G.Pregnancy-specific glycoproteins (PSGs) are members of the immunoglobulin superfamily and are closely related to the predominantly membrane-bound CEACAM proteins. PSGs are produced by placental trophoblasts and secreted into the maternal bloodstream at high levels where they may regulate maternal immune and vascular functions through receptor binding and modulation of cytokine and chemokine expression and activity. PSGs may have autocrine and paracrine functions in the placental bed, and PSGs can activate soluble and extracellular matrix bound TGF-β, with potentially diverse effects on multip...
Domingues RR, Ginther OJ, Gomez-Leon V, Castro T, Wiltbank MC.In heifers and mares, multiple pulses of prostaglandin F2alpha (PGF) are generally associated with complete luteal regression. Although PGF pulses occur before and during luteolysis, little is known about the role of minor PGF pulses during preluteolysis on subsequent luteal and endometrial PGF production that may initiate luteolysis. Heifers (n = 7/group) and mares (n = 6/group) were treated with a single minor dose of PGF (3.0 and 0.5 mg, respectively) during mid-luteal phase (12 and 10 days postovulation respectively). After treatment, a transient decrease in progesterone (P4) con...
Hunyadi L, Datta P, Rewers-Felkins K, Sundman E, Hale T, Fajt V, Wagner S.The objective of this study was to determine the pharmacokinetic parameters of oclacitinib maleate as a top dress given to adult horses. Six adult horses with a mean weight of 528Â kg were administered a single dose of 0.5Â mg/kg oclacitinib maleate. Blood was collected prior to drug administration and at 15Â min, 30Â min, 45Â min, 1, 2, 4, 6, 8, 12, 24, 48, and 72Â h after treatment. Oclacitinib maleate plasma concentrations were measured by liquid chromatography/mass spectrometry. Pharmacokinetic parameters were found best to fit a one-compartment model. Mean C was 486Â ng/ml (range 423-549Â...
Monteiro RA, Cunha RM, Guerra MMP, de Almeida VM, Peña-Alfaro CE, Silva SV.The aim of this study was to test equine semen cryopreservation techniques for the conservation of donkey germplasm. Ejaculates of three male donkeys were used (n = 18; six ejaculates per donkey; six repetitions), collected by the artificial vagina method. To remove the seminal plasma, the ejaculates were split and submitted to filtration or centrifugation methods. To assess the freezing method, each fraction was submitted to the automated system or the conventional system, and groups were formed: automated centrifuge, automated filtrate, conventional centrifuge and conventional filtrate. Af...
Castro T, Jacob JC, Domingues RR, Ginther OJ.Prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α) are involved in equine embryo mobility throughout the uterus on Days 11-15 (ovulation = Day 0). On a day (Day 12) of maximal embryo mobility in pregnant mares (n = 13) and before luteolysis in nonbred mares (n = 10), gene expressions were compared between the uterine horns that did and did not contain the mobile embryo and between pregnant and nonbred mares. A cytobrush was used to collect an endometrial sample from the middle of each uterine horn. In nonbred mares, there was no difference for any of the considered gene expressions ...
Pratt S, Barnes TS, Cowling N, de Klerk K, Rainger J, Sole-Guitart A, Woldeyohannes S, Goodwin W.To compare arterial blood pressure (ABP) measured invasively (IBP) to ABP measured non-invasively (NIBP) via oscillometry in healthy anaesthetised and standing horses using the Bionet BM7Vet. Fourteen horses were anaesthetised for elective procedures (anaesthetised group) and 10 horses were enrolled for standing blood pressure manipulation (standing group). In both groups, IBP and NIBP-corrected to heart level were measured every 3 min using the Bionet BM7Vet. The overall mean difference (bias), standard deviation and limits of agreement (LOA) were calculated for paired IBP and NIBP systolic (...
Hinrichsen SL, Yuen KY, Dryburgh EL, Bertin FR, Stewart AJ.Pituitary pars intermedia dysfunction (PPID) is diagnosed by increased basal or post thyrotropin-releasing hormone (TRH) stimulation ACTH concentrations. ACTH is known to be unstable; however, the effect of different temperatures and TRH stimulation on equine ACTH stability is poorly described. In total, 15 horses, including 8 PPID positive (ACTH > 35 pg/mL at baseline or >65 pg/mL 30 min after TRH stimulation), were divided into 2 groups: 9, including 5 PPID positive, with basal ACTH concentrations and 6, including 3 PPID positive, with post TRH stimulation ACTH concentrations. Whole bl...
Lançoni R, Celeghini ECC, Gonella-Diaza AM, Júnior VG, de Carvalho CPT, Zoca GB, Garcia-Oliveros LN, Batissaco L, Oliveira LZ, de Arruda RP.This study aimed to assess the semen ubiquitin levels of stallions with good (GF) and poor semen freezability (PF) and to evaluate the relationship between sperm ubiquitination and sperm morphological defects. Five ejaculates from eight adult stallions (n = 40) were collected and cryopreserved. Then, the ubiquitin level in equine sperm cells was assessed by immunohistochemistry with epifluorescence microscopy, and sperm morphology was assessed by differential interference contrast microscopy. Sperm cells were classified according to the intensity (classification 1: from I to IV; I = very l...
Knickelbein KE, Lassaline ME, Kim S, Scharbrough MS, Thomasy SM.To determine corneal thickness (CT) and axial anterior chamber depth (ACD) using ultrasound biomicroscopy (UBM) in normal adult horses. To compare corneal thickness measurements between UBM and ultrasonic pachymetry. Methods: Sixty eyes of 30Â healthy adult horses aged 8-24Â years. Methods: Ultrasonic pachymetry (velocity of 1640Â m/s) was utilized to obtain measurements of the central, superior, temporal, inferior, and nasal cornea. Triplicate images of the same corneal locations were acquired using UBM (50Â MHz). Images of the axial anterior chamber were used to measure ACD. Intraocular pres...
Maśko M, Lewczuk D, Szarska E, Domino M.A horse learning about the entrance to narrow, cage-shaped places may be challenging both for the horses as well as for the owners. For some behaviors, such as loading into a trailer or climbing onto a treadmill, the final behavioral goal can be achieved by working towards it in stages. This study compared the successive approximation of horses to their first work on a treadmill with horses hardly ever loaded (HE L) and regularly loaded (R L) into a trailer. Fourteen horses were divided into two groups (HE L n = 7 and R L n = 7) based on their experiences of entering into a trailer. Al...
Dai F, Costa ED, Giordano A, Heinzl EUL, Giongo P, Pagnozzi G, Cannas S, Minozzi G, Minero M.Horses preparation for competition may cause psychological and physical stress. Physical vascular therapy BEMER® is reported to increase vasomotion and microcirculation, supporting body healing. This study aimed at assessing whether BEMER® physical vascular therapy in horses influences recovery rate of hematological and biochemical blood parameters within 1 h after moderate exercise and reduces stress measured by physiological and behavioral indicators. This prospective, randomized, double blinded, placebo-controlled crossover study included twelve warmblood horses (3 mares, 8 geldings, 1 s...
Calzone S, Wilkins C, Deckers I, Nankervis K.The EquiAmi Training Aid (ETA) is a popular training and rehabilitation tool, however knowledge about its effect on the equine gait is lacking. Understanding of its effects on equine kinematics, and the clinical relevance of these effects is vital to promote optimal use of training aids within training and rehabilitation programmes. Therefore, this study aimed to determine how the ETA influences horses' gait kinematics at walk and trot. Eight horses walked and trotted in-hand with and without the ETA. Optical motion capture was used to measure forelimb and hindlimb pro- and retraction angles, ...
Fernández-Hernández P, GarcÃa-MarÃn LJ, Bragado MJ, Domingo A, González-Fernández L, MacÃas-GarcÃa B.In the horse, a repeatable protocol for in vitro fertilization has not been developed, possibly due to incomplete sperm capacitation. We have previously identified the metabolites present in equine oviductal fluid (OF). We aimed to test the effects of different metabolites found in equine oviductal fluid on quality parameters of frozen-thawed spermatozoa. Different concentrations of myoinositol (5-25 mM), lactate (6-60 mM), glycine (0.1-5 mM), β-alanine (1-6 mM), and histamine (0.05-0.4 mM) were added independently to modified Whitten's medium (pH = 7.25). Thawed equine spermatozoa (three s...
Bryan K, McGivney BA, Farries G, McGettigan PA, McGivney CL, Gough KF, MacHugh DE, Katz LM, Hill EW.A single bout of exercise induces changes in gene expression in skeletal muscle. Regular exercise results in an adaptive response involving changes in muscle architecture and biochemistry, and is an effective way to manage and prevent common human diseases such as obesity, cardiovascular disorders and type II diabetes. However, the biomolecular mechanisms underlying such responses still need to be fully elucidated. Here we performed a transcriptome-wide analysis of skeletal muscle tissue in a large cohort of untrained Thoroughbred horses (n = 51) before and after a bout of high-intensity exe...
Mendonça T, Bienboire-Frosini C, Menuge F, Leclercq J, Lafont-Lecuelle C, Arroub S, Pageat P.Equine-assisted therapies (EATs) have been widely used in the treatment of patients with mental or physical conditions. However, studies on the influence of equine-assisted therapy (EAT) on equine welfare are very recent, and the need for further research is often highlighted. The aim of this study was to investigate whether EAT creates negative or positive emotions in horses, and the influence of patients' expectations (one group of patients had physical and psychological expectations and one group of patients had only psychological expectations) on horses' emotional responses. Fifty-eight pa...
Bowers S, Gandy S, Anderson B, Ryan P, Willard S.The objective of this study was to investigate use of digital infrared thermal imaging (DITI) to determine whether surface temperature gradient differences exist between pregnant and nonpregnant mares as a noncontact method to determine pregnancy status. On the day measurements were collected, each pregnant mare (n=10; beginning at 292.4+/-1.4 d of gestation) was paired with a nonpregnant mare (n=17). Ambient temperature, DITI measurements (left and right flank, wither temperatures [i.e., animal surface control] and background temperature), and rectal temperatures were obtained every 7 d for 5...
Nagao S, Osuka H, Yamada T, Uni T, Shomura Y, Imai K, Higuchi Y, Hirota S.Myoglobin (Mb) stores dioxygen in muscles, and is a fundamental model protein widely used in molecular design. The presence of dimeric Mb has been known for more than forty years, but its structural and oxygen binding properties remain unknown. From an X-ray crystallographic analysis at 1.05 Å resolution, we found that dimeric metMb exhibits a domain-swapped structure with two extended α-helices. Each new long α-helix is formed by the E and F helices and the EF-loop of the original monomer, and as a result the proximal and distal histidines of the heme originate from different protomers. Th...
Milner PI, Fairfax TP, Browning JA, Wilkins RJ, Gibson JS.To determine the effects of varying O(2) on pH homeostasis, based on the hypothesis that the function of articular chondrocytes is best understood at realistic O(2) tensions. Methods: Cartilage from equine metacarpophalangeal/tarsophalangeal joints was digested with collagenase to isolate chondrocytes, and then loaded with the pH-sensitive fluorophore 2',7'-bis-2-(carboxyethyl)-5(6)-carboxylfluorescein. The radioisotope(22)Na(+) was used to determine the kinetics of Na(+)/H(+) exchange (NHE) and the activity of the Na(+)/K(+) pump, and ATP levels were assessed with luciferin assays. Levels of ...
Cocchia N, Pasolini MP, Mancini R, Petrazzuolo O, Cristofaro I, Rosapane I, Sica A, Tortora G, Lorizio R, Paraggio G, Mancini A.New studies are underway to find new methods for supporting longer storage of cooled stallion semen. It is known that high concentrations of reactive oxygen species (ROS) cause sperm pathology. The metalloprotein superoxide dismutase (SOD) is responsible for H(2)O(2) and O(2) production, by dismutation of superoxide radicals. The aim of this study is to assess the quality of chilled stallion semen processed with extenders containing SOD at different concentrations as antioxidant additives. A total of 80 ejaculates collected from 5 standardbred stallions was divided into 5 aliquots treated as: ...
Nyman G, Funkquist B, Kvart C, Frostell C, Tokics L, Strandberg A, Lundquist H, Lundh B, Brismar B, Hedenstierna G.The anatomical basis of gas exchange impairment in the anaesthetised horse was studied by computerised tomography (CT; three shetland ponies) and morphological analysis (one pony and three horses). By means of CT, densities were seen in dependent lung regions early during anaesthesia, both with spontaneous breathing and with mechanical ventilation. The densities remained for some time where they had initially been created when the animal was turned from dorsal to sternal recumbency. Deep insufflation of the lungs reduced the dense area. Gas exchange was impaired roughly in proportion to the de...
Van Cleemput J, Poelaert KCK, Laval K, Maes R, Hussey GS, Van den Broeck W, Nauwynck HJ.The respiratory epithelium of humans and animals is frequently exposed to alphaherpesviruses, originating from either external exposure or reactivation from latency. To date, the polarity of alphaherpesvirus infection in the respiratory epithelium and the role of respiratory epithelial integrity herein has not been studied. Equine herpesvirus type 1 (EHV1), a well-known member of the alphaherpesvirus family, was used to infect equine respiratory mucosal explants and primary equine respiratory epithelial cells (EREC), grown at the air-liquid interface. EHV1 binding to and infection of mucosal e...
Geddes LA, Tacker WA, Rosborough JP, Moore AG, Cabler PS.Electrical ventricular defibrillation of heavy subjects (over 100 kg body weight) is uncommon for the human or any animal species. This paper reports trans-chest ventricular defibrillation of subjects ranging in weight from 2.3 to 340 kg using conventional defibrillation current (heavily damped sine wave) of 0.3-30 ms duration. It was found that a body weight-to-electrical-shock strength relationship exists and can be expressed in terms of either electrical energy or peak current. For the duration of current pulse used clinically (3-10 ms), the relationship between energy requirement and body ...
Kim JY, Jung HJ, Yoon MJ.Expression of the protein DDX4/MVH, or VASA, has been reported in germ cells of several species. The main objectives of this study were to (i) investigate VASA expression patterns in testicular cells of stallions at two different reproductive stages (pre-pubertal and post-pubertal) and (ii) evaluate the use of VASA antibody as a molecular marker for single germ cells from stallions. Testicular tissues were obtained from stallions and categorized as pre-pubertal and post-pubertal based on the formation of lumen and status of spermatogenesis on the cross section of seminiferous tubules. The resu...
Weber JA, Freeman DA, Vanderwall DK, Woods GL.The hypothesis that treatment of pregnant mares with prostaglandin E2 (PGE2) hastens the oviductal transport of equine embryos was tested by treating bred mares with PGE2 on Day 3 after ovulation and subsequently measuring the rate of hastened oviductal transport (estimated by the uterine embryo recovery rate on Day 4 after ovulation). In a preliminary, noncontrolled experiment, oviductal transport was apparently not hastened after intramuscular, intrauterine, or intraperitoneal PGE2 administration to bred mares (0/6, 0/3, and 0/3 mares, respectively). Oviductal transport appeared to be hasten...
Shahar R, Zaslansky P, Barak M, Friesem AA, Currey JD, Weiner S.Young's modulus and Poisson's ratios of 6mm-sized cubes of equine cortical bone were measured in compression using a micro-mechanical loading device. Surface displacements were determined by electronic speckle pattern-correlation interferometry. This method allows for non-destructive testing of very small samples in water. Analyses of standard materials showed that the method is accurate and precise for determining both Young's modulus and Poisson's ratio. Material properties were determined concurrently in three orthogonal anatomic directions (axial, radial and transverse). Young's modulus va...
Nixon AJ, Begum L, Mohammed HO, Huibregtse B, O'Callaghan MM, Matthews GL.Autologous chondrocyte implantation (ACI) has been used clinically for over 15 years and yet definitive evidence of chondrocyte persistence and direct impact on cartilage repair in full-thickness lesions is scant and no data are available on ACI in partial-thickness defects in any animal model. This study assessed the effect of chondrocytes secured using periosteal overlay in partial- and full-thickness cartilage defects in the equine model. Paired cartilage defects 15 mm in diameter were made in the patellofemoral joint of 16 horse and repaired with ACI or periosteal flap alone. Response wa...
Young LE, Marlin DJ, Deaton C, Brown-Feltner H, Roberts CA, Wood JL.Maximum oxygen uptake also appears to correlate to athletic performance in horses. In the Thoroughbred industry, there has long been an empirical theory that heart size is related to athletic performance, despite a lack of scientific evidence supporting this assertion. To investigate the relationship between peak oxygen consumption (VO2max) and cardiac size measured by echocardiography, guided M-mode and 2-dimensional echocardiography were performed in 17 conditioned Thoroughbreds with a range of VO2max from 126 to 217 ml/min/kg STPD (mean +/- s.d. 158 +/- 28 m/min/kg). Horses were age 2-10 ye...
Mok CH, Urschel KL.Evaluating amino acid requirements, specifically threonine requirements, in horses will enable better feed formulation and result in economic production, improved animal health, and reduced environmental pollution. However, the current knowledge of protein and amino acid requirements in horses is still limited. Because horses have a unique digestive system and consume a variety of feed ingredients, their protein digestibility may be affected than other species by different feed composition, and thus amino acid requirements are susceptible to vary between situations. Therefore, a careful evalua...
Nagata K, Tsukita S, Tamura T, Sone N.A Helicobacter pylori membrane fraction oxidized yeast and equine cytochrome c, and N,N,N',N'-tetramethyl-p-phenylenediamine (TMPD). When ascorbate was used as reductant, the Vmax and apparent Km values were 612 nmol electron min-1 (mg protein)-1 and 14 microM for yeast, and 419 nmol electron min-1 (mg protein)-1 and 19 microM for equine cytochrome c, respectively. For TMPD oxidation, the Vmax and Km values were 640 nmol electron min-1 (mg protein)-1 and 182 microM, respectively. These oxidase activities showed a high affinity for oxygen. Inhibition of both cytochrome-c and TMPD oxidase activi...
Couto MA, Harwig SS, Lehrer RI.Equine neutrophil antimicrobial peptide 2 (eNAP-2), a recently described antimicrobial peptide isolated from equine neutrophils, was found to selectively inactivate microbial serine proteases (subtilisin A and proteinase K) without inhibiting mammalian serine proteases (human neutrophil elastase, human cathepsin G, and bovine pancreatic trypsin). Although the primary structure of eNAP-2 resembled that of several known antiproteases that belong to the 4-disulfide core peptide family, this pattern of selectivity is unique. eNAP-2 formed a noncovalent complex with native subtilisin A or proteinas...
Malekipour F, Whitton C, Oetomo D, Lee PV.Despite the important role of subchondral bone in maintaining the integrity of the overlying articular cartilage, little research has focused on measuring its mechanical behavior, particularly under injurious load conditions such as impact compression. In this study, the stiffness and the absorbed energy of subchondral bone were compared to that of its overlying cartilage by applying impact compression to equine cartilage-bone specimens. Deformations of the cartilage and subchondral bone were examined independently within the cartilage-bone unit by analyzing real-time images of cartilage-bone ...
Soboll G, Horohov DW, Aldridge BM, Olsen CW, McGregor MW, Drape RJ, Macklin MD, Swain WF, Lunn DP.We have previously demonstrated that hemagglutinin (HA) gene vaccination and influenza virus infection generate protective antibody responses in equids. However, these antibody responses differ substantially in that particle mediated DNA vaccination does not induce an immunoglobulin A (IgA) response. A study was performed to investigate the regional immunoregulatory mechanisms associated with these different immune responses. Ponies were either vaccinated with equine HA DNA vaccines at skin and mucosal sites, infected with influenza virus or left untreated and influenza-specific antibody respo...
Sieme H, Harrison RA, Petrunkina AM.Success in cryopreserving stallion semen has been very variable. Several different freezing regimes have been published. However, because extenders and procedures used in each regime have differed, direct comparison of these techniques has been very difficult, and controlled studies comparing different techniques have not been reported. A number of different factors affect sperm cryosurvival. In this article we review briefly current cryopreservation procedures for stallion semen, and then in more detail cryobiological determinants of sperm function, and mechanisms of cryoinjury and cryoprotec...
Suh TK, Schenk JL, Seidel GE.Sexing sperm by high-speed flow cytometry subjects them to high pressure. The routine operating pressure of the MoFlo SX flow cytometer for sperm sorting for commercial production has been 50 pounds/square inch (psi), with a standard 70 microm standard nozzle tip. It was hypothesized that lowering the sorting pressure could reduce sperm damage. Therefore, a series of experiments using semen from six bulls, sorted with three MoFlo SX sorters, was conducted to determine optimal pressure. An additional experiment was done with stallion spermatozoa. In Experiment 1, sorting at 30 psi compared to 5...
Padalino B, Raidal SL.The regulations for minimal space and direction of travel for land transport in horses vary worldwide and there is currently no definitive guidance to promote equine health and welfare. This study evaluated the effects of bay size and direction of travel (forwards/backwards) in horses by comparing the behavioural, physiological, laboratory and gastroscopy parameters between transported and confined horses. A total of twenty-six mares took part in the study; 12 horses were confined for 12 h, and all mares underwent 12 hours' transportation, travelling in single (n = 18) or wide bays (n = 8), an...
Fitzgerald DM, Anderson ST, Sillence MN, de Laat MA.Generalized obesity, regional adiposity, hyperinsulinemia and hypertriglyceridemia are all potential indicators of equine metabolic syndrome (EMS). This study aimed to assess the relationship between morphometric measurements of body condition and metabolic hormone concentrations in ponies, with and without a neck crest or generalised obesity. Twenty-six ponies were assigned a body condition score (BCS) and cresty neck score (CNS). Height, girth, and neck measurements were taken. An oral glucose test (OGT; 0.75g dextrose/kg BW) was performed and blood samples collected prior to and 2 hours pos...
Jolly RD, Palmer DN, Dalefield RR.Analytical studies of three lipopigments show that much can be achieved. Lipopigment from ovine ceroid-lipofuscinosis is composed of discrete protein and lipid molecules in orderly arrays and lipid peroxidation is not involved in its formation. Subunit c of mitochondrial ATP synthase accounts for approximately 50% of accumulated material and is specific to the disease process in this and other forms of the disease. Lipofuscin from bovine heart was mostly soluble and also contained discrete proteins, lipids and metals. Equine thyroid lipofuscin was less soluble but also had a relatively high pr...
Jansson A, Lindberg JE.Most athletic horses are fed a high-starch diet despite the risk of health problems. Replacing starch concentrate with high-energy forage would alleviate these health problems, but could result in a shift in major substrates for muscle energy supply from glucose to short-chain fatty acids (SCFA) due to more hindgut fermentation of fibre. Dietary fat inclusion has previously been shown to promote aerobic energy supply during exercise, but the contribution of SCFA to exercise metabolism has received little attention. This study compared metabolic response with exercise and lactate threshold (VLa...
Wieser B, Tichy A, Nell B.Guinea pigs have a very low threshold of corneal sensitivity and at the same time nearly no reflex tearing compared to dogs, cats, and horses. The question arose whether there is a general correlation between corneal sensitivity and the quantity of reflex tearing. Methods: Totally 160 animals of 8 different species (20 animals per species) were investigated. Methods: The corneal touch threshold (CTT) was measured with a Cochet-Bonnet esthesiometer. The palpebral fissure length (PFL) was measured with a calliper ruler. The Schirmer tear test (STT) was modified by adapting the width of the STT s...
Kacskovics I.Many of the receptors for the Fc domain of immunoglobulins in cattle, sheep, pigs and horses have been cloned and characterized recently. This review summarises recent developments and relates them to the current understanding of the primary structure, cellular specificity and binding properties of Fc receptors (FcRs). Although there is an obvious overall similarity to their human and mouse counterparts, some Fc receptors in domestic animals are unusual, perhaps most notably the bovine Fcgamma2R, which although related to other mammalian FcgammaRs, belongs to a novel gene family and the porcin...
