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.
West JB, Mathieu-Costello O.Exercise induced pulmonary haemorrhage (EIPH) is a serious problem in the Thoroughbred industry. The condition apparently occurs essentially in all Thoroughbreds in training but the mechanism has proved elusive. There is now strong evidence that the condition is caused by mechanical failure of the walls of the pulmonary capillaries when the pressure inside them rises to very high levels. It is well known that pulmonary capillaries have extremely thin walls to allow rapid exchange of respiratory gases across them. Recently we have shown that the wall stresses are very large when the capillary t...
Marr CM.Echocardiography is an extremely versatile tool for both the equine clinician and physiologist. There are three useful forms of echocardiography, B mode, M mode and Doppler. Together they provide complementary information on cardiac disease and haemodynamic status. B mode is used to image the cardiac chambers, valves, myocardium and pericardium. M mode allows determination of motion of cardiac structures; it is superior to B mode for timing of events and it is used to make precise measurements of the heart. Doppler echocardiography can assess intracardiac blood flow and its velocity. Echocardi...
Les CM, Keyak JH, Stover SM, Taylor KT, Kaneps AJ.The purpose of this study was to investigate the relationships between data obtained from quantitative computed tomography and mechanical properties in the equine metacarpus, as measured in vitro in bone specimens. Three hundred and fifty-five bone specimens from the metacarpi of 10 horses were machined into right cylinders aligned with the long axis of the bone. A computed tomographic scan of the specimens, along with a Cann-Genant K2HPO4 calibration standard, was obtained. The specimens then were compressed to failure, and the elastic modulus, yield stress, yield strain, strain energy densit...
Gibson JS, Godart H, Ellory JC, Staines H, Honess NA, Cossins AR.Potassium transport was measured in equine red blood cells, using 86Rb+ influx as a convenient assay. A significant component of volume- and pH-sensitive K(+)-Cl- cotransport to the overall K+ flux was observed in all blood samples studied, although fluxes were variable between animals, and within individuals when measured at intervals over a period of weeks. The aryloxyacetic acid [(dihydroindenyl)oxy]alkanoic acid (DIOA), at a final concentration of 100 microM, inhibited most (> 95%) of the Cl(-)-dependent K+ flux, and DIOA sensitivity was therefore used to define the activity of the K(+)...
Brinsko SP, Ball BA, Miller PG, Thomas PG, Ellington JE.This study was designed to investigate the development of day 2 embryos obtained from young and aged mares, co-cultured with oviductal epithelial cells obtained from mares in each age group in a 2 x 2 crossover design. Young, fertile mares (n = 19; 2-7 years of age) and aged, subfertile, mares (n = 16; 17-24 years of age) were used as embryo and oviductal epithelial cell donors. Embryos (n = 37) were collected from the oviducts 2 days after ovulation and were paired (embryos obtained from young mares with embryos obtained from aged mares) so that eight pairs were co-cultured with young mare ov...
Redina OE, Amstislavsky SYa , Maksimovsky LF.This study examined the developmental capacity of oocytes in DD mice after they had been injected with pregnant mares' serum gonadotrophin at different stages of the oestrous cycle. The superovulation of mature DD mice at pro-oestrus, oestrus and metoestrus resulted in a large yield of viable embryos. The proportion of abnormal embryos was highest after injection of pregnant mares' serum gonadotrophin at dioestrus. The pool of viable oocytes was most synchronized with normal development after the hormone was injected at oestrus. The results demonstrate that oocytes of different morphology coul...
Taddei N, Buck M, Broadhurst RW, Stefani M, Ramponi G, Dobson CM.The stability and equilibrium unfolding behaviour of horse muscle acylphosphatase have been studied by denaturing the protein under various conditions of temperature, pH, and urea concentration. Far-ultraviolet circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy indicate that this small monomeric protein unfolds reversibly and cooperatively. Thermodynamic parameters, the Gibbs free energy delta G and enthalpy delta H of unfolding, have been estimated for denaturation of the protein from NMR and CD data as 19 kJ mol-1 and 350 kJ mol-1, respectively. CD and 1H-NMR results s...
Müller W, Firsching R.The Magneson and Titan yellow tests were used to detect Mg in amyloid deposits in primary and secondary amyloidosis, in a pituitary tumour and in a case of equine cutaneous amyloidosis. Especially vascular amyloid deposits turned out to contain high levels of Mg. The significance of these findings remains unclear at present. Competition between Mg and Ca, the relationship between Mg in elastic fibres and amyloid P-component, and the high water content of amyloid along with the interaction of Mg with water are discussed.
Xu X, Arnason U.The sequence of the mitochondrial (mt) DNA of the horse (Equus caballus) was determined. The length of the sequence presented is 16,660 bp. This figure, however, is not absolute due to pronounced heteroplasmy caused by variable numbers of the motif GTGCACCT in the control region of different molecules. Boundaries of the 13 peptide-coding genes were determined by the presence of start and stop codons, and by analogy with other eutherian mtDNAs. Three genes (COIII, NADH3 and NADH4) were not terminated by a stop codon. Comparison among the peptide-coding genes of the horse and eight other mammals...
Manohar M, Goetz TE, Hutchens E, Coney E.Right atrial, pulmonary artery, pulmonary capillary, pulmonary artery wedge, and systemic blood pressures of strenuously exercising horses increase markedly. As a consequence, myocardial metabolic O2 demand in exercising horses must be high. Experiments were, therefore, carried out on 9 healthy, exercise-conditioned horses (2.5 to 8 years old; 481 +/- 16 kg) to ascertain the regional distribution of myocardial blood supply in the atria and ventricles at rest and during exercise. Blood flow was measured, using 15-micron-diameter radionuclide-labeled microspheres that were injected into the left...
Lawrence LA, Ott EA, Miller GJ, Poulos PW, Piotrowski G, Asquith RL.Twenty-five pairs of equine third metacarpals (McIII) were collected from horses of varying breeds and ranging in age from 1 d to 27 yr. Standard three-point bending tests were performed on the McIII to obtain comparative data on breaking load (BL), breaking strength (BS), and elasticity (E). Broken bones were reassembled and 2-cm sections cut from the bone 1 cm below the nutrient foramen and at the site of the break. Bone mineral content (BMC) and geometrical properties of these sections were determined. Maximum BMC (17.3 g/2 cm) was reached at 6.0 +/- 1.8 yr of age. Horses in this study achi...
Abass BT, Weaver BM, Staddon GE, Waterman AW.The pharmacokinetics of thiopentone sodium administered intravenously as a single dose (11 mg/kg) were studied in acepromazine pre-medicated horses and ponies in which anaesthesia was maintained with either halothane (Group 1) or isoflurane (Group 2). The results showed that the disposition kinetics of thiopentone in horses and ponies were best described by a three-compartment open model. In plasma, a very short initial distribution phase in both horses and ponies, half-life 1.4 +/- 1.2 min (mean +/- SD) and 1.3 +/- 0.7 min, respectively, was obtained, which was followed by a second comparativ...
Poitras P, Guay P, Vaillancourt D, Zidane N, Bigras-Poulin M.The main objective of this study was to evaluate two freezing protocols and the effect of agar embedding on survival of day 6.5 equine embryos. A total of 133 embryos were used, in one group (n = 51), embryos were first embedded in agar before the freezing protocol was started. A freezing protocol to -30 degrees C or -33 degrees C was used before plunging embryos into liquid nitrogen (LN2). The embryos were thawed in water at 37 degrees C, evaluated and placed in culture. After 24 h culture, the embryos were evaluated for their morphology and development. No differences were observed between e...
Popel AS, Johnson PC, Kameneva MV, Wild MA.The purpose of this study was to show that two rheological parameters, red blood cell (RBC) sedimentation rate and apparent blood viscosity at low shear rate, characterizing the degree of RBC aggregation, correlate significantly with the maximal mass-specific rate of oxygen consumption or aerobic capacity (VO2max). Comparisons were made within two groups of similarly sized athletic and sedentary species: group 1, pronghorn antelope, dog, goat, and sheep; and group 2, horse and cow. The pronghorn antelope (Antilocapra americana) is one of the most athletic mammals, and we have obtained data on ...
Ellis MJ, Mulligan RS, Evans MJ, Donald RA.Antagonists are useful for probing hormone action and receptor characteristics. In this study we have investigated the inhibitory effects of analogues of arginine vasopressin (AVP) and corticotrophin-releasing hormone (CRH) on stimulated release of immunoreactive ACTH from perifused equine anterior pituitary cells in vitro. Our aims were to gain some insight into the characteristics of the CRH and AVP receptors of the horse pituitary and to establish whether the response induced by AVP and CRH together could be blocked by combining antagonists. Experimental design included 5-min pulses of AVP ...
Linford RL.Quantitated locomotion analysis is increasingly being used during assessment and treatment of gait disorders in human beings. Locomotion analysis is also thought to have potential for enhancing the assessment of lameness in horses. Availability of high-speed video recording systems has simplified the process of quantitated locomotion analysis; however, the high cost of such systems has limited their use for routine clinical assessment in horses. The temporal resolution of 500- to 1,000-images/s (Hz) recording systems is beyond what has been considered necessary for precise quantitation of shor...
Bedford SJ, Hinrichs K.It has recently been reported that large insemination volumes might affect fertility of mares. The results from these studies are confounded by other factors, however, such as inadequate number of spermatozoa in the inseminate. We conducted a study to test whether volume alone affects fertility when sufficient numbers of spermatozoa are present. Semen from one stallion was collected, extended at 50 x 10(6) spermatozoa/ml, and stored in a commercial semen cooling device for 18 to 30 h before insemination. Ten pony mares were assigned during estrus in random pairs to be bred every other day with...
McClure SR, Watkins JP, Bronson DG, Ashman RB.Axial stability of equine oblique proximal phalangeal osteotomies with application of the standard short limb cast or 1 of 3 configurations of transfixation casts was determined in vitro. Transfixation cast methods included use of parallel pins, divergent pins, or parallel pins incorporating a metal walking bar. Displacement at the osteotomy was recorded for each limb at 4,448 N. Standard short limb casts provided significantly (P = 0.0002) less axial stability than did any form of transfixation cast. Significant differences were not found between the 3 transfixation casts.
Elliott J, Bryant CE, Soydan J.Isolated equine digital veins were examined in vitro to study the importance of the endothelium in the responses to both vasodilator and vasoconstrictor agents and to characterise the endothelial-derived mediators involved. Carbachol (Cch; 1 microM) and bradykinin (Bk; 1 nM) caused relaxation of U44069-induced tone by 79.5 +/- 0.35% and 73.7 +/- 4.0% respectively. Mechanical removal of the endothelium completely prevented relaxant responses to Cch and to Bk showing they were mediated by the endothelium. Treatment of veins with NG-nitro-L-arginine methyl ester (L-NAME; 30 and 300 microM) inhibi...
Dyhre-Poulsen P, Smedegaard HH, Roed J, Korsgaard E.The dampening of hoof impact was investigated by measuring the accelerations transmitted through structures of the hoof in horses trotting freely on an asphalt tarmac. The hoof dampened the vibrations transmitted to the first phalanx. Shoeing decreased the viscous dampening and increased the median power frequency and the maximal amplitude of the vibrations transmitted to the first phalanx. The pressure inside the digital cushion of the foreleg was recorded. The pressure dropped during the stance phase, indicating expansion of the hoof. The expansion of the hoof was not produced by frog or sol...
Smith BL, Jones JH, Carlson GP, Pascoe JR.It has been hypothesised that horses have a preference for facing backward in a trailer during road transport in order to minimise shifts of body weight due to accelerations and decelerations. To determine if horses have preferences for facing forward vs. backward in a horse trailer, the authors analysed the percentages of time horses spent in different body positions and directions while standing in a moving or parked horse trailer. Body positions and directions of 8 Thoroughbred geldings were videotaped while horses were transported singly and untethered in a 4-horse stock trailer over a 32 ...
Rawlings P, Mellor PS.The presence at different latitudes and the seasonal distribution of two known or potential vectors of African horse sickness (AHS) virus--Culicoides imicola and C. obsoletus--were investigated in the Iberian peninsula using light trap collections. Culicoides imicola was present as far north as 41 degrees N but not at 43 degrees N (Asturias, Spain), whereas C. obsoletus was found at all latitudes. In the northern part of the distribution of C. imicola, adults of this species were present for only a few months of the year, but adults were continually present further south. Culicoides obsoletus ...
Joujou-Sisic K, Granérus M, Wetterling H, Wikström K, Engström W, Jeffcott L, Schofield PN, Welin A.The expression of the insulin like growth factor (IGF) II gene has been examined in the developing equine fetus. It was found that IGF II transcripts were present in abundant quantities in third trimester embryonic and extraembryonic tissues as for example the placenta. The expression of the IGF II gene was high in the fetal liver where two prominent transcripts--4.6 and 4.1--kB were produced. However, these transcripts could not be traced in the adult liver. Instead we found two different transcripts with the sizes of 4.0 and 2.9 kB in the adult liver. These findings taken together with the d...
Kato Y, Sayama Y, Sano M, Kaneko MK.Podoplanin (PDPN), which is a mucin-type membrane glycoprotein, is expressed on lymphatic endothelial cells and epithelial cells of many organs. PDPN is also overexpressed in several malignant cancers, and its expression is associated with cancer progression and poor prognosis. Human PDPN possesses three platelet aggregation-stimulating (PLAG) domains and the PLAG-like domain (PLD), which binds to C-type lectin-like receptor-2 (CLEC-2). Previously, we reported a novel antihorse PDPN (horPDPN) monoclonal antibody (mAb), PMab-219, using Cell-Based Immunization and Screening (CBIS) method. PMab-2...
Bampidis V, Azimonti G, Bastos ML, Christensen H, Durjava M, Kouba M, López-Alonso M, López Puente S, Marcon F, Mayo B, Pechová A, Petkova M....Following a request from the European Commission, EFSA was asked to deliver a scientific opinion on the safety and efficacy of a tincture from the fruit of L. (anise tincture) when used as a sensory additive in feed and water for drinking for all animal species. The product is a ■■■■■ solution, with a dry matter content of approximately 1.6%. The product contained on average 0.0414% polyphenols (of which 0.0144% were flavonoids), 0.0009% anisaldehyde, 0.0003% anethole. Estragole (≤ 1.2 mg/kg) was detected in the additive. The estimated maximum content of furocoumarins was 8.2...
Hedberg Y, Dalin AM, Santesson M, Kindahl H.Strong oestrous symptoms in the mare can cause problems with racing, training and handling. Since long-acting progesterone treatment is not permitted in mares at competition (e.g. according to FEI rules), there is a need for methods to suppress unwanted cyclicity. Spontaneous dioestrous ovulations in the late luteal phase may cause a prolongation of the luteal phase in mares. Methods: In this preliminary study, in an attempt to induce ovulation during the luteal phase, human chorionic gonadotropin (hCG) (3000 IU) was injected intramuscularly in four mares (experimental group) in the luteal pha...
Gao KX, Chen NB, Liu WJ, Li R, Lan XY, Chen H, Lei CZ, Dang RH.Gray horses are born colored, and they then gradually lose their hair pigmentation. Tremendous progress has been made in identifying the genes responsible for graying with age in horses in recent years. Results show that gray coat color in horses is caused by a 4.6-kb duplication in intron 6 of the syntaxin 17 gene (STX17), which constitutes a cis-acting-regulatory mutation. However, little is known about the gray phenotype in native Chinese horses. This study was conducted to explore the frequency distribution of the gray mutation in native Chinese horse breeds. A total of 489 samples from 14...
Mawhinney I, Davis N, Carson T, Torrens N, Wales A.The study examined and compared the sensitivity of culture and a quantitative PCR assay for screening equine semen for the presence of Taylorella equigenitalis (CEMO). Chilled semen samples, both raw and treated with extender, from two stallions were spiked with the organism at seven or 23 days postejaculation and prepared in serial dilutions. Culture of the 7-day raw semen readily detected CEMO at all dilutions, but extended semen yielded counts that were two log cycles lower at equivalent dilutions, with the organism being nearly undetectable at the maximal dilutions. By contrast, PCR sensit...
Bakala A, Karlik W, Wiechetek M.In this study a detailed description of the equine hepatocyte isolation procedure is presented. Livers were obtained from horses slaughtered at the local slaughterhouse. For blood removal and liver preservation the following steps are suggested: perfusion with the oxygenated HBSS (0-2 degrees C, with continuous flow of 500-800 ml/min for 3-6 min), protection from ischemia injury by flushing with ice-cold University of Wisconsin Solution (UW, flow rate of 500-800 ml/min), and finally immersion of the liver lobe in UW solution (2 degrees C) during its transport to the laboratory. For equine isol...
Hermanson JW, Hegemann-Monachelli MT, Daaod MJ, LaFramboise WA.The biceps brachii of horses is subdivided into a lateral and medial head. Electrophoresis of samples from the lateral head revealed three slow-migrating native myosin isoforms, including one that does not correspond to slow myosin isoforms described for other mammalian muscles. In contrast, the medial head contained a single slow isoform. Both the lateral and medial heads contained three fast-migrating isoforms corresponding with the FM-2, FM-3 and FM-4 isoforms reported for other mammalian fast-twitch muscle fibers. Electrophoresis of myosin heavy chains (MHCs) revealed only two MHC bands, o...
Álvarez C, González N, Luño V, Martínez F, Gil L.The aim of this study was to test and compare two new components in extenders for freezing donkey semen: mare colostrum and jenny colostrum. Colostrum was obtained from four mares and four jennies right after the foal's birth. Ejaculates were collected from five fertile donkeys. Sperm samples were pooled, diluted and cryopreserved in three different experimental extender groups: lactose supplemented with egg yolk extender (20%) as the control group, lactose supplemented with jenny colostrum extender (20%), and lactose supplemented with mare colostrum extender (20%). After thawing, we evaluated...
Monahan CM, Chapman MR, Taylor HW, French DD, Klei TR.Moxidectin was tested for efficacy in ponies against experimental infections of 56 day Strongylus vulgaris larvae and 11 day Parascaris equorum larvae. Three dosages of moxidectin were tested: 300 micrograms per kg live body weight, 400 micrograms per kg, and 500 micrograms per kg, and the vehicle served as control. Ponies were first infected with 600 S. vulgaris third-stage larvae (L3) on Experiment Day 0 and then with 3000 embryonated P. equorum eggs on Day 45. Moxidectin treatments were administered on Day 56 and necropsy examinations were performed on Day 91. Strongylus vulgaris fourth-sta...
Waelchli RO, Jaworski T, Ruddock WD, Betteridge KJ.Equine blastocyst fluid has a lower [Na+], a higher [K+] and a lower osmolality than does normal blood serum. Based on the assumptions that the sodium pump is primarily responsible for fluid accumulation and that ions transported actively into the blastocyst increase blastocyst osmolality above that of the external medium, we hypothesized that the [Na+] and the osmolality of mare uterine fluid are lower than those of blastocyst fluid. Microdialysis and ion chromatography were used to estimate [Na+] and [K+] of uterine fluid. Mares (n=10) were used for in vivo measurements at different stages o...
Courtney CH.Few studies investigating the seasonal transmission of equine cyathostomes have been done in warm climates. Two Australian studies used experimentally-infected plots to determine hatching, development and survival of free living stages of equine cyathostomes. Four studies in the southern United States used pasture larval counts, and in some instances tracer animals, to determine seasonal availability of infective cyathostome larvae on naturally-infected pastures. With the exception of the dry Australian tropics, a general pattern of peak transmission of cyathostomes during the cooler seasons o...
Nie GJ, Johnson KE, Wenzel JG.Mares were inseminated deep in the uterine horn with 25 million sperm selected by glass wool/Sephadex (GWS) filtration, Percoll separation (PS) or absolute number (AN). Deep-horn insemination using a low-volume, smooth tipped, flexible pipette/catheter delivery system allowed more efficient use of stallion sperm and reduced post-breeding uterine reaction in mares. Mares were pregnant in 15/30, 13/30 and 10/30 cycles for GWS, PS and AN selection methods, respectively. Sperm selection method did not effect pregnancy outcome (P=0.422). However, sperm selected for deep-horn insemination by filtrat...
Dahl VE, Hitchens PL, Stover SM.OBJECTIVE To determine the effects of racetrack surface and shoe characteristics on formation of wear grooves in the horseshoes of racehorses. SAMPLES 1,121 horseshoes from 242 Thoroughbred racehorses collected during routine horseshoeing procedures at 4 racetracks with dirt or synthetic surfaces. PROCEDURES Data for 1,014 horseshoes from 233 racehorses were analyzed. Horseshoes were photographed, and length and width of grooves formed at the heels of the solar surface of horseshoes were measured on the photographs. Effects of racetrack, racetrack surface, and shoe characteristics (eg, shoe si...
Aurich C, Aurich JE, Parvizi N.In equine species, luteinising hormone (LH) and prolactin (PRL) release are reduced throughout pregnancy but increase at foaling. The present experiments were designed to study a possible opioidergic regulation of LH and PRL release in pregnant Shetland mares (n=6). At various stages of pregnancy (days 26.4+/-0.6, 75.4+/-5.4, 171.8+/-2.4, 226.2+/-4.8, 282.7+/-3.4 and 319.8+/-2.1), mares were injected with the opioid antagonist naloxone (0.5 mg/kg body weight) and saline. The two treatments were always separated by 2 days, and mares served as their own controls. Two hours after being given nalo...
Šichtař J, Šimoník O, Bubeníčková F, Svobodová J, Nehasilová A.The aim of our study was to investigate the effect of two freezing extenders and two packaging systems on motility, plasma membrane (PM) integrity, and the apoptotic status of frozen-thawed (F-T) spermatozoa of the endangered Old Kladruber stallions. The collected semen (n = 6 stallions, three collections each) was diluted either with Gent or Lactose-EDTA (Lact) extender. Two aliquots of semen from each collection diluted in this way were prepared and then loaded into 5-mL aluminum tubes or 0.5-mL plastic straws. After thawing and then at 15 minutes intervals within 1 hour, the samples were ...
Andrews FM, Doherty TJ, Blackford JT, Nadeau JA, Saxton AM.To determine the effects of orally administered omeprazole, as enteric-coated capsules, on baseline and stimulated gastric acid secretion in horses. Methods: 5 healthy 8-year-old mixed-breed horses fitted with gastric cannulas. Methods: Enteric-coated granules of omeprazole were mixed with corn syrup and administered orally once daily for 5 consecutive days. On days 1 and 5 beginning 5 hours after omeprazole administration, 4 gastric fluid samples were collected, each for 15 minutes, via the gastric cannula (baseline samples). Pentagastrin was administered IV as a constant infusion for the sub...
Kurotaki T, Narayama K, Oyamada T, Yoshikawa H, Yoshikawa T.An immunohistochemical study was carried out on the kinetics of Langerhans cells (LCs) at various pathological stages of "Kasen". Skin lesions of "Kasen" that were collected by biopsy from May to October were classified histopathologically into three stages: initial (Group I, 31 cases), developing (Group II, 50 cases) and regressing (Group III, 13 cases). LCs showed a positive reaction with anti-equine thymocytes (EqT6) monoclonal antibody (MoAb) and anti-major histocompatibility complex (MHC) class II MoAb by immunohistochemical staining. The anti-EqT6 MoAb was intensely positive along the cy...
Ferreira-Silva JC, Basto SRL, Moura MT, Rocha JM, Freitas Neto LM, Santos Filho JP, Silva Filho ML, Oliveira MAL.The work described here aimed to verify the efficiency of different extenders for cryopreservation of equine semen using sperm motility and acrosin activity as spermatic parameters. The semen was fractioned into two equal parts and resuspended in an 11% lactose solution in a 1:1 proportion, where it remained for 20 minutes at room temperature. The semen was centrifuged at 600 g for 10 minutes, and after the second centrifugation, each pellet received the freezing extender (Merck or Zorlesco) and was loaded into 4 mL straws. Each straw was placed in liquid nitrogen vapor steam for 15 minutes ...
Lieto LD, Cothran EG.A cDNA library was built using RNA extracted from the skin tissue of an adult horse. The library was primed with oligo (dT) and sequences were directionally inserted in order to produce an expression library. The library has 5.8X 10(5) plaque forming units with 99.6% recombinant phage. The average insert size is 1.3 Kbp. Three hundred and thirteen expressed sequence tags (ESTs) were generated from sequencing of the 5 prime end of randomly selected skin cDNA clones. The ESTs were sequenced on an ABI 377 using Big-Dye chemistry. A similarity search was performed on each EST using the NCBI non-re...
Hatzipanagiotou A, Rieland E, Enbergs H.It was the aim of this project to investigate the changes of the lysozyme activity in the milk of mares during the lactation period. Further on the influence of race, date of conception and foaling, age and number of lactations on the lysozyme activities in milk was analysed. Milk samples were collected from 44 mares (trotters, warmblood, quarter horses) from eight farms between the 1st and 90th day p. p. The activity of the lysozyme was measured by a turbidometric method. Summarizing the following results are obtained: Lysozyme activities in mare milk of the 1st and 3rd day p. p. were higher ...
Reef VB.A wide variety of ultrasonographic equipment currently is available for use in equine practice, but no one machine is optimal for every type of imaging. Image quality is the most important factor in equipment selection once the needs of the practitioner are ascertained. The transducer frequencies available, transducer footprints, depth of field displayed, frame rate, gray scale, simultaneous electrocardiography, Doppler, and functions to modify the image are all important considerations. The ability to make measurements off of videocassette recorder playback and future upgradability should be ...
Les CM, Keyak JH, Stover SM, Taylor KT.Three-dimensional finite element (FE) models of the left metacarpi of five adult horses were developed from quantitative computed tomography data, using the algorithms of Keyak et al. (1990, J Biomed. Engng 12, 389-397). The metacarpi were then equipped with 12 rosette strain gauges and loaded non-destructively in a mechanical testing machine. The bones and the models were loaded in axial compression, with the load evenly distributed across the distal row of carpal bones, and with a point load placed mediad to the sagittal midline, to a load equivalent to three times body weight (-15 kN); and ...
Castejón-Riber C, Muñoz A, Trigo P, Riber C, Santisteban R, Castejón F.Significant differences exist in the respiratory adaptation to exercise in different equine breeds. This research describes the ergoespirometric response to exercise of Andalusian (AN) and Arabian (A) horses, both selected according to morphological criteria. Thirteen untrained male horses (6 AN and 7 A) performed a treadmill exercise test (TET) with a slope of 6%, with workloads starting from 5 m/s and increasing 1 m/s every 3 min until the horses were not able to keep the required velocity. Tidal volume (TV), respiratory rate, minute ventilation (VE), oxygen uptake (VO2), carbon dioxide prod...
Scott MA, Liu IK, Overstreet JW, Enders AC.Uterotubal junction tissues (n=12) recovered from young nulliparous mares 4 h after insemination were examined for spermatozoa in situ using scanning electron microscopy. Mares were inseminated before ovulation with semen containing 66-85% morphologically abnormal spermatozoa and approximately 1 x 10(9) progressively motile spermatozoa. Spermatozoa were found in all the tissues and displayed a variety of relationships to the epithelium, depending on regional location, spatial constraints and epithelial surface characteristics. Spermatozoa were most abundant in the epithelial folds on the uteri...
Moodley Y, Baumgarten I, Harley EH.We investigated the applicability of microsatellite primers, designed in horses, for use in plains and mountain zebras. Fifteen of the 20 tested horse-isolated primer pairs reliably amplified polymorphic loci in two wild equid species. We used this information to assess whether levels of genetic variation and repeat size differed in species from which microsatellites were isolated and in closely related target species. Target equid species exhibited similar levels of genetic variation to the horse, the species from which primers were originally isolated. We show that ascertainment bias results...
Forsman C, Jonsson BH, Lindskog S.The 250 MHz 1H-NMR spectrum of horse carbonic anhydrase I (or B) (carbonate hydro-lyase, EC 4.2.1.1) was measured as a function of pH under various conditions. Eight resonances corresponding to histidine C-2 protons and four resonances corresponding to histidine C-4 protons were identified and assigned to individual histidine residues in the enzyme molecule. Substantial similarities between horse and human carbonic anhydrases I were demonstrated. While the human enzyme has three titratable histidine residues in its active site, the horse enzyme has only two, His-67 in the human enzyme being re...
Pool-Anderson K, Raub RH, Warren JA.Six pairs of full-sibling Quarter Horse foals were produced by non-surgical embryo transfer and immediate rebreeding of donor mares. Each pair of donor/recipient mares consisted of one multiparous (donor) and one nulliparous (recipient) mare of similar body type and size. Milk yield was determined within 2 d of 8, 15, 22, 29 d (early lactation); 45, 60 d (midlactation); and 90, 120 d (late lactation) postpartum by the weigh-suckle-weigh method. On the following day, milk samples were collected, and foals were weighed and measured for wither height, heart girth, metacarpal length, metatarsal le...
Hagedorn HW, Schulz R.The use of diuretics in horses subject to doping control is prohibited. Thus, a sensitive screening procedure is required to identify the chemically different diuretics. We communicate here a method to detect three commonly employed acidic diuretics: bumetanide, ethacrynic acid, and furosemide. A liquid-liquid extraction on Extrelut 3 was performed at weak acidic and basic conditions using ethyl acetate as organic solvent. For analysis by GC, the diuretics were methylated on-column in the presence of MSTFA/TMAH, avoiding the commonly employed highly toxic derivatizing agent methyl iodide. For ...
MacLeod JN, Kalbfleisch TS.The first equine reference genome was completed in 2007 and published in 2009. This major accomplishment has enabled equine science to advance in ways that broadly parallel the transformative impact that genomics has had on many animal species including humans. A conceptual overview of reference genomes, genome annotation, and the major implications for equine science is presented. The relationship between genomic sequencing and the accelerating application of precision P4 medicine is discussed in the context of human and equine patients. Emergent technologies built on the foundation of genomi...
