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.
Lund RJ, Guthrie AJ.This study determined the maximal O2 uptake (VO2max) of Thoroughbred horses acclimatised to mild hypobaric conditions using a standard exercise test on a treadmill inclined at a 7% slope. The O2 uptake (VO2) versus speed relationship was linear below the exercise intensity required to attain VO2max. The VO2max of individual horses ranged from 143.5 to 172.6 ml/kg/min. The proportion of total variance for the VO2 versus speed relationship was greater than 0.992, and the coefficients of variation in repeated tests in individual horses ranged between 0.07 and 1.54%. The VO2 versus speed relations...
Ozawa A, Inokuma H, Johke T.The relationship between plasma insulin-like growth factor-I (IGF-I) level and body weight was studied in six breeds of horse. The correlation coefficients between plasma IGF-I and body weight in males and females of 1 year old heavy horses (Percheron and Breton breeds) were 0.62 and 0.12 respectively. The mean plasma IGF-I of males was higher than that of females (p < 0.01). However, the plasma IGF-I levels of heavy horses did not exceed those of light horses (Thoroughbred) or ponies (Shetland and Falabella). These data suggest that IGF-I is at least related to the difference of body weights ...
Broad TE, Forrest JW, Lewis PE, Pearce PD, Phua SH, Pugh PA, Stewart-Scott IA.A DNA repeat element, revealed initially by digestion of horse DNA with TaqI, was cloned and characterized by Southern and in situ hybridization studies and nucleotide sequencing. The clone, e4/1, consisted of 32 tandem reiteration of a unit repeat of 21-22 bp, and produced multilocus DNA fingerprinting profiles that were useful for parentage analysis in horses. The tandem repeat element was shown by in situ hybridization to be localized in the centromeres of the acrocentric but not metacentric classes of horse chromosomes.
Moslemi S, Silberzahn P, Gaillard JL.19-Norandrostenedione was synthesized in vitro from dehydroepiandrosterone by explants of equine full-term placenta. The synthesis of 19-norandrostenedione was inhibited by two specific aromatase inhibitors, 4-hydroxyandrostenedione and fadrozole.
Broad TE, Ede AJ, Forrest JW, Lewis PE, Phua SH, Pugh PA.DNA repeats, revealed initially by digestion of horse DNA with restriction enzymes, were cloned and characterized by cross-hybridization studies and nucleotide sequencing. The Sau-like family of tandem repeats contained two classes of repetitive elements with unit repeats of about 80 bp that shared no sequence similarity. Both unit repeats were present, frequently in tandem, in cloned segments of horse DNA of less than 600 bp. Evidence is presented, based on their ladderlike patterns of hybridization to horse DNA and their high level of similarity to published sequences of satellites from equi...
Escribano BM, Castejon FM, Santisteban R, Aguera EI, Rubio MD.A study has been made of the variations experienced by the hemogram and blood volume indices in 16 Andalusian horses after carrying out an exercise test of increasing intensity consisting of 3 sequences of 1000 m each, before and after being subjected to a daily exercise programme for two months. Samples were taken by external jugular vein puncture: while at rest, within the first minute of finalizing each exercise stage and at 10 and 15 minutes of recovery. Both the red blood cells and the hematocrit value showed a significant decrease in their mean values after two months training; conversel...
Jolly WT, Whittem T, Jolly AC, Firth EC.The dose-related effects of phenylbutazone and Depo-Medrol on chondrocyte viability and chondrocyte-mediated synthesis and depletion of proteoglycans were investigated using cultured explants of equine middle carpal joint articular cartilage. Explants from 12 horses (941 x 3 mm diameter) were cultured for a total of 5 days, which included 3 days' exposure to either phenylbutazone (0, 2, 20, 200 or 2000 micrograms/mL) or Depo-Medrol (0, 20, 200 or 2000 micrograms/mL). For each explant, amino sugar content was used as a measure of proteoglycan content, 35S incorporation as a measure of the rate ...
Palmer JL, Bertone AL, Malemud CJ, Carter BG, Papay RS, Mansour J.The relevance of site and the influence of exercise on third carpal articular cartilage proteoglycan (PG) were assessed in 16 horses. Six horses were exercised (exercised group) for 30 minutes, 3 times/wk, for 6 weeks. The other 10 horses (nonexercised group) were housed in box stalls for the same 6-week period. At week 6, articular cartilage from the proximal surface of the right third carpal bone was harvested and cultured with radioactive sulfate to label newly synthesized PG. Endogenous PG was measured by use of a uronic acid assay. Newly synthesized and endogenous PG were characterized by...
McConaghy FF, Hales JR, Rose RJ, Hodgson DR.Five horses were exercised on a treadmill [to central blood temperature (Tcore) approximately 42.5 degrees C]. Three of those horses were heated at rest in a climate room (53 degrees C, 90% relative humidity) (to Tcore approximately 41.5 degrees C). Temperatures were measured in the rectum, hypothalamus (Thyp), cerebrum, and cavernous sinus (Tsinus), on the skin of the head and midside, and Tcore. When Tcore increased above 38.5 degrees C, Thyp remained 0.6 +/- 0.1 degree C (SE) lower during heat exposure and 1 +/- 0.2 degrees C lower during exercise. During heat exposure, Tsinus was 2.2 +/- 0...
Sojka JE, Levy M.This article outlines strategies on how to approach equine endocrine disorders based on clinical signs and clinical pathologic data. In the 1987 Veterinary Clinics of North America: Equine Practice article on evaluating equine endocrine function, Beech stated that the numbers of hormonal assays available to use in horses was limited. Unfortunately, not much has changed since then. With the advent of convenient assay kits for many hormones and cofactors available in human medicine, it is possible to submit samples to laboratories for measurement of a wide range of endogenous substances. Caution...
Panu R, Bo Minelli L, Sanna L, Zedda M, Acone F, Gazza F, Palmieri G.The retractor clitoridis muscle originates from the coccygeal vertebrae in the cow, ewe, goat and mare, and from the anal musculature in the sow. It terminates at the base of the clitoris. In all the species considered, a vegetative innervation was found. This was represented by isolated or grouped ganglion cells. Nervous sensitive supply was also present. This was represented by Pacinian, Pacinian-like and Golgi-Mazzoni's corpuscles, and by Krauses's end bulbs. A notable difference was found in the amount and type of these receptors. They were numerous in the sow, ewe and goat, and rare in th...
Chirnside ED, Francis PM, Mumford JA.A series of recombinant fusion proteins derived from equine arteritis virus (EAV) open reading frame (ORF) 7 have been used to define the immunoreactive region of the viral nucleocapsid (N) protein. Reactivities of recombinant N fusion proteins with post-infection equine sera in immunoblots and ELISAs indicate that the major nucleocapsid protein epitope is located within amino acid residues 1-69. In ELISAs two recombinant nucleocapsid fusion proteins containing residues 1-69 (rN1-69) and 1-28 (rN1-28) discriminated between pre- and post-infection, and pre- and post-vaccination serum samples. A...
Jones JH, Carlson GP.The metabolic power required for sustained exercise in the horse is proportional to running speed. Moderately fast speeds require substantial energy expenditure and result in the generation of a massive metabolic heat load. Quantitative estimates of energy expenditure and heat production of horses at various running speeds were developed using empirically derived data from treadmill studies. Total metabolic power represents the sum of aerobic power indicated by the rate of oxygen consumption and net anaerobic power indicated by the rate of plasma lactate accumulation. These data were applied t...
Vatistas NJ, Meagher DM, Gillis CL, Neves JW.Twenty-two horses were examined because of firearm injuries. Nine had been shot with .22-caliber bullets, 2 with BB pellets, 6 with buckshot, 1 with a .35-caliber bullet, and 1 with an airgun pellet. Injury was confined to the skin or skeletal muscles in 8 horses. Of these, 7 returned to their previous use. In 14 horses, injuries to additional structures were incurred, including the sinus and pharynx (n = 2), mandible (n = 1), tooth (n = 1), aorta (n = 1), eye (n = 3), tibia (n = 1), gastrointestinal tract (n = 3), joint (n = 1), and trachea (n = 1). The 3 horses that had only eye injuries wer...
Les CM, Stover SM, Willits NH.Paired metacarpi obtained at necropsy from 100 horses ranging in age from term fetus to 35 years were examined to estimate the prevalence and sites of metacarpal fusion. Metacarpal fusion was seen in 192 of 200 metacarpi, and 78% of all horses 2 years or older had 2 or more fusions. Fusion of the second metacarpal bone to the third metacarpal bone was significantly (P < 0.001) more common than was fusion of the fourth to the third metacarpal bone. Fusions appeared for the most part in pairs and were bilaterally symmetric. Rooney-Prickett type-A carpometacarpal joint configurations (in which...
McCutcheon LJ, Geor RJ, Hare MJ, Ecker GL, Lindinger MI.The objective of this study was to determine the composition and extent of sweat losses during submaximal exercise under hot and humid conditions and to compare these findings with the same exercise protocol conducted under cool, dry and hot, dry conditions. Five Thoroughbred horses (age 3 to 6) completed exercise tests under each of 3 environmental conditions in random order: cool, dry (CD), room temperature (T) = 20 degrees C, relative humidity (RH) = 45-55%; hot, dry (HD), T = 32-34 degrees C, RH = 45-55%; and hot, humid (HH), T = 32-34 degrees C, RH = 80-85%. Horses exercised at 50% of the...
White SL, Williamson LH, Maykuth PL, Cole SP, Andrews FM, Geiser DR.The exercise intensity of horses (n = 175) competing in the cross-country phase of 4 combined training events at 5 levels of competition [novice (N), training (T), preliminary (P), intermediate (I) and advanced (A)] was investigated. Environmental conditions varied from cool and humid (mean +/- s.d. temperature and humidity = 12.1 degrees C +/- 0.6 and 88.4% +/- 8.9 RH) to moderately hot and humid (27.8 degrees C +/- 2.1 and 62.5% +/- 7.8 RH). Heart rates (beats/min) were recorded continuously at 5 s intervals with a heart monitor. Mean +/- s.d. heart rates (beats/min) for each level of compet...
Palmer JL, Bertone AL, Mansour J, Carter BG, Malemud CJ.The relevance of site and exercise on the biomechanical properties of the articular cartilage from the equine third carpal bone were assessed by creep indentation testing. Six horses were exercised for 30 minutes three times weekly. Another six horses were housed in box stalls and were not exercised. At the conclusion of the study, one third carpal bone from each horse was harvested and the KLM biphasic material properties of cartilage were determined at 12 sites. There was a significant (p < 0.01) effect of site but not exercise on the cartilage aggregate modulus, which was significantly l...
White SL, Williamson LH, Maykuth PL, Cole SP, Andrews FM.The exercise intensity of horses competing in 3-day combined training events at 3 different levels of competition (CCI, n = 7; CCI, n = 11; CCI, n = 23) was investigated. Environmental conditions during all events were cool with 100% cloud cover. Heart rates were continuously recorded at 5 s intervals by a heart rate monitor. Mean +/- s.d. heart rate for all horses during each phase were: Phase A = 118 +/- 11 beats/min, Phase B = 179 +/- 22.7 beats/min, Phase C = 129 +/- 13.9 beats/min and Phase D = 174 +/- 19.6 beats/min. Mean +/- s.d. heart rates on Phase A and C were significantly different...
Schroter RC, Marlin DJ.There is a need to determine objectively the environmental heat load imposed on horses competing to an international standard in 3-day-events in environments where there is likely to be a high level of radiation added to high ambient temperatures and relative humidity; the presently used FEI 'Comfort Index' is severely limited in its applicability. It is proposed that the Wet Bulb Globe Temperature (WBGT) Index be used. This index was originally established for man exercising strenuously under harsh climatic conditions with high solar radiation levels. It may be defined as: WBGT = 0.7Twb + 0.3...
Brinsko SP, Ball BA, Ignotz GG, Thomas PG, Currie WB, Ellington JE.The time of activation of the embryonic genome (maternal-embryonic transition) in equine embryos was investigated by assessing incorporation of 3H-uridine and nucleolar development. In Experiment 1, embryos were recovered from the oviduct (n = 15) and the uterus (n = 3). Recovered embryos were assessed for morphologic development and quality score. Recovered embryos with less than 8 cells (two cells, n = 4; four cells, n = 5; five cells, n = 2) were incubated with 3H-uridine (560 microCi/ml) for 10 hr, while eight-cell embryos (n = 2), morulae (n = 2), and blastocysts (n = 3) were incubated wi...
Aurich C, Daels PF, Ball BA, Aurich JE.The aim of the present study was to investigate the role of ovarian steroids in the opioid regulation of LH and prolactin release in mares. Effects of the opioid antagonist naloxone on LH and prolactin secretion were determined in ovariectomized pony mares. The animals were pretreated with either progesterone (500 micrograms kg-1) or oestradiol benzoate (10 micrograms kg-1) for 8 days and subsequently with a combination of progesterone and oestradiol for an additional 8 days. Naloxone administration (0.5 mg kg-1 i.v.) resulted in a significant release of LH as well as prolactin in mares after ...
Guillaume D, Zarazaga LA, Malpaux B, Chemineau P.In long-day breeders like horses, the length of nocturnal melatonin secretion is the main messenger of photoperiod. Previous studies have shown that the nocturnal jugular melatonin concentration is lower in horses, than in mules but is unknown in donkeys. The aim of this study was to estimate the inter-animal variability of plasma melatonin concentration in domestic mares and to compare this concentration with those observed in domestic jennies and in their hybrid mules. In the autumn, blood samples were collected at 22 h, 23 h, 0 h and 1 h during 2 nights at 3 weeks intervals, in 110 pony mar...
Gray AW, Davies ME, Jeffcott LB.We report on novel methods to isolate osteoclasts (OC s) and generate osteoclast-like cells (OCL s) from the bone and bone marrow of the equine femur. OC s were successfully isolated from bone scrapings taken from the endosteal surface of the femurs of three horses. OCL s were generated from bone marrow cells taken from the same animals. The validity of using the formation of OCL s as a method for studying OC differentiation and activity was confirmed by the similar characteristics of these two cells. In particular, they both were multinuclear, expressed the enzyme tartrate resistant acid phos...
Bio SystemsFebruary 27, 2023
Volume 225 104871 doi: 10.1016/j.biosystems.2023.104871
Bhattacharjee S.Adaptations in equine limbs, including fusion of its bones, such as the metapodials II and IV (splint bones) with metapodial III (cannon bone), have been debated. It is argued that cursorial adaptations in equine limbs with a progressive reduction in the number of digits lighten up the limbs and facilitate fast running. Similar fusions in other bones, such as the radius and ulna, tend to exhibit similar traits. For example, the fusion often occurs in a disto-proximal direction while leaving sharp ridges. This article proposes a model to understand the biomechanical advantages that a fused symm...
Auer DE.The role of oxygen-derived free radicals is considered critical to the etio-pathogenesis of equine inflammatory joint disease. In vivo, the superoxide radical in the joint may be derived either from activated polymorphonuclear leukocytes or from an ischemia/reperfusion cycle. In the presence of ferrous iron, it may generate the highly reactive hydroxyl radical (OH *). Predisposing factors may include synovitis, exercise-induced ischemia and minor traumatic injury to the joints. Unlike other inflammatory mediators, oxygen-derived free radicals may damage tissue directly and these reactive speci...
López ML, de Souza W.The presence and distribution of cholesterol in mature and immature epididymal spermatozoa was analyzed using filipin as a cytochemical tool in freeze-fracture replicas and thin section preparations. The polyenic-antibiotic filipin formed complexes with 3, beta -OH sterols, producing characteristic protrusions, or pits, that were heterogeneously distributed in the plasma membrane of stallion spermatozoa, revealing a specific organization in a functionally specialized area of the gamete. The acrosomal region of the sperm head presented a significantly higher density of filipin sterol complexes ...
Harris P.This review outlines the energy sources available to the horse, from its diet and from its body stores, at rest and while exercising. It looks at the current ways of describing the energy potential of diets fed to horses and discusses the relative advantages and disadvantages of the digestible energy and net energy systems. The more empirical net energy system for calculating the energy available for maintenance and work is compared with a more physiological partitioning system. Finally, the energy requirements for maintenance and exercise are discussed, together with how they may be practical...
Leach DH, Zoerb GC.The mechanical properties of pigmented equine hoof wall tissue were determined for samples taken from the inner and outer portions of the stratum medium of the toe. Two properties, the modulus of elasticity and proportional limit, which are measures of the rigidity and yield point, respectively, of the tissue, were studied for samples compressed in 3 orthogonal directions. All samples tested were anisotropic. Inner wall samples were less rigid and had a lower yield point than outer wall samples.
Art T, Lekeux P.In order to study the in vitro mechanical properties of the equine trachea submitted to the compressive pressures observed in vivo, the pressure-volume relationship was determined in intra- and extra-thoracic tracheal segments taken post mortem from 29 healthy horses (one to 15 years old; 352 to 651 kg). At the same time, the cross-sectional lumen area (X-SA) at the mid-point of the segment was measured using a slit-lamp transillumination and photographic measurement by endoscopy. The tracheal specific compliance (Cs) as well as the relative changes in X-SA and in the sagittal and transverse d...
Moudgal NR, Papkoff H.The ability of equine luteinizing hormone (eLH) to promote follicular growth and maturation in hypophysectomized rats has been assessed. A single injection of equine LH has been shown to promote the growth of a large number of antral and preovulatory follicles. In addition, equine LH markedly increased serum estrogen levels and uterine weight. Furthermore, equine LH, like equine chorionic gonadotropin (eCG; PMSG) was able to significantly enhance the incorporation of [3H]thymidine into ovarian DNA, an activity shown to be specific to hormones having follicle-stimulating hormone (FSH) activity....
Rodriguez J, Maserati M, Robilotta T, Augusto G, Alonso MA, Redoan M, Tibary A, Fleury P.Field collection of oocytes in mares using transvaginal follicular aspiration (TVA) for embryo production has the potential to revolutionate the equine industry. Protocols for TVA in specialized laboratory settings have been described in the scientific literature since the early 1980s. The objective of this study was to determine the success rate of TVA oocytes recovery under ambulatory conditions. A secondary goal of this study was to determine if TVA is associated with any health complications when performed by recently trained practitioners in the field. Follicles (n = 296) from 66 adult c...
Falvo D'Urso Labate G, Baino F, Terzini M, Audenino A, Vitale-Brovarone C, Segers P, Quarto R, Catapano G.One of the hardest tasks in developing or selecting grafts for bone substitution surgery or tissue engineering is to match the structural and mechanical properties of tissue at the recipient site, because of the large variability of tissue properties with anatomical site, sex, age and health conditions of the patient undergoing implantation. We investigated the feasibility of defining a quantitative bone structural similarity score based on differences in the structural properties of synthetic grafts and bone tissue. Methods: Two biocompatible hydroxyapatite porous scaffolds with different nom...
Dunnett CE, Marlin DJ, Harris RC.The aim of the present study was to relate changes in muscle oxidative capacity and free fatty acid flux in response to oil supplementation to fuel utilisation during subsequent exercise of varying intensities. Following 10 weeks of oil supplementation there was an increased capacity for fat utilisation during low and moderate intensity exercise as indicated by a lower respiratory exchange ratio (RER) (P<0.05). We suggest that this was contributed to by a parallel increase in the oxidative capacity of muscle as indicated by a significant increase in the activity of muscle citrate synthase (...
Pearson RA, Lawrence PR, Smith AJ.Draught animal research carried out by scientists at the Centre for Topical Veterinary Medicine (CTVM) in Edinburgh and overseas is reviewed and the major findings are reported. The remit for the work has been to provide basic information on draught animals which can be applied by researchers and extension workers to their own geographic situations. Instrumentation is described which has been designed and manufactured to assist in the measurement of draught animal performance, particularly work output and energy consumption. Energy requirements of cattle, buffaloes and equids for work and ways...
Madigan J, Costa L, Nieves S, Horgan M, Weberg K, Aleman M.Stranded and recumbent equids often require emergency rescue, and a successful rescue often requires vertical lifting of the animal. Currently, the devices used for vertical lifting of equids are not readily available at an incident or urgent situation. The current study describes and evaluates the use of a simple lift device utilizing commercially available, and reasonably priced, equipment. The system, referred to as the Loop Vertical Lift System or Loops System, is basically composed of four round slings placed in such a way that utilizes the skeletal system for support. The study demonstra...
Bernor RL, Cirilli O, Bukhsianidze M, Lordkipanidze D, Rook L.The Equus datum has been established as a geochronologic 'instantaneous' migratory event of a North American Equus species into Eurasia at the beginning of the Pleistocene (2.58 Ma). A remarkable radiation of Equus followed across Eurasia and Africa. Dmanisi includes excellent remains of Equus, well calibrated between 1.85 and 1.76 Ma. Our morphologic and morphometric analyses of the augmented Dmanisi Equus sample support the co-occurrence of Equus stenonis and Equus altidens in the sequence. Dmanisi E. stenonis is found to be morphologically similar to the European E. stenonis populations a...
Schelp C, Böse R, Micha A, Hentrich B.High-titre equine immune sera were used to screen a lambda gt 11 expression library of Babesia equi cDNA fragments. Two cDNA clones which did not cross-hybridize to each other were studied. Both clones hybridized specifically to DNA from B. equi but not to DNA from B. caballi, B. divergens or B. ovis. Recombinant proteins were expressed as glutathione S-transferase (GST) fusion proteins with apparent molecular weights of 40 kDa and 75 kDa. Polyclonal antibodies directed against the 40 kDa and 75 kDa recombinant proteins detected native antigens of 55 kDa and 50 kDa respectively in crude lysate...
Bietzk E, Weller R, Simons V, Channon SB.Development of new methods for anatomy teaching is increasingly important as we look to modernize and supplement traditional teaching methods. In this study, a life-sized equine model, "Geoff," was painted with surface and deep anatomical structures with the aim of improving students' ability to convert theoretical knowledge into improved topographical anatomy knowledge on the live horse. Third and fourth year veterinary medicine students (n = 45) were randomly allocated into experimental (used "Geoff") and control (used textbook) groups. The efficacy of the model was evaluated through a struc...
Hawkes J, Hedges M, Daniluk P, Hintz HF, Schryver HF.Preference trials were conducted with mature ponies. In Trial 1, oats were compared with oats plus sucrose. Four of six pony geldings selected oats plus sucrose, but one pony demonstrated a dislike for sucrose and one selected from the bucket on the right side regardless of content. Oats, maize, barley, rye and wheat were compared in Trial 2 using six mature pony mares. Oats were the preferred grain, with maize and barley ranking second and third respectively. Wheat and rye were the least preferred. Even though the ponies demonstrated preference, the total intake at a given meal was not greatl...
Squires EL, Hillman RB, Pickett BW, Nett TM.Thirty-two light-horse mares were confirmed to be pregnant and assigned to one of four treatments: (1) injected with 250 micrograms of Equimate on day 70 and again on day 77 if abortion had not occurred; (2) injected with 250 micrograms of Equimate on day 70 and every 24 hr until abortion occurred (maximum four injections); (3) injected with 250 micrograms of Equimate on day 70 and every 12 hr until abortion (maximum eight injections); and (4) injected with 250 micrograms of Equimate once only on day 35 of gestation. Mares were observed four times daily for incidence of abortion or side effect...
Legg KA, Gee EK, Breheny M, Gibson MJ, Rogers CW.The Thoroughbred racing industry faces new and competing pressures to operate within a modern, changing society. Three major moderators drive the focus and productivity of the industry worldwide: economic sustainability, horse biology and social licence to operate. This review proposes that despite the apparent homogeneity in the structure of racing across jurisdictions due to international regulation of the sport, there are significant differences within each jurisdiction in each of the three moderators. This creates challenges for the comparison of injury risk factors for racehorses within t...
Human movement scienceNovember 30, 2018
Volume 63 82-95 doi: 10.1016/j.humov.2018.11.007
Goodworth AD, Barrett C, Rylander J, Garner B.As perturbation training is gaining popularity, it is important to better understand postural control during complex three-dimensional stimuli. One clinically relevant and commonly used three-dimensional stimulus is found in hippotherapy and simulated hippotherapy on a mechanical horse. We tested nine healthy participants on a horse simulator, measured head and trunk kinematics, and characterized data in time (root-mean-square and variability) and frequency (amplitude spectra, gains, and phases) domains. We addressed three fundamental questions: 1) What is the specificity of postural responses...
McGill S, Coleman B, Hayes M.Cooling out horses is a common practice after intense exercise. Typical cooling procedures include both walking and drenching (often with scraping). The cool out is performed to ensure the horses physiologic responses returned to a baseline range as quickly as possible. The use of water in cool out provides the greatest potential for removing heat from the animals. However, adding air velocities that can increase evaporation rates from the horses can potentially increase the rate of cool out; thereby reducing the time until the horses' physiologic measurements return to baseline. This study me...
Campbell ML, England GC.Uterine contractions may play an important role in the transportation of spermatozoa towards the site of fertilisation in the oviduct of mares. M-mode ultrasound was used to measure the number, amplitude and duration of uterine contractions in each uterine horn and the uterine body of oestrous mares for four minutes before and four minutes after either coitus, or the artificial insemination of either 80.0 ml of fresh semen or 10.0 ml of fresh semen. The direction of the uterine contractions in each uterine horn and the uterine body was measured before and after coitus. Coitus and the inseminat...
McClure SR, Watkins JP, Ashman RB.Breaking strength (torque at failure) of equine third metacarpal bones, with transfixation pins placed parallel in the frontal plane and 30 degrees divergent from the frontal plane, was determined in vitro. Two transfixation pins were placed through the distal metaphysis, using a jig designed to drill the holes in the assigned configuration. Paired metacarpal bones II through IV from 12 horses were tested in torsion. The torsional moment of the force applied through the transfixation pins at failure was compared for each limb. Metacarpal bones with divergent pins were significantly (P = 0.030)...
Knight DA, Tyznik WJ.Fourteen Quarter Horse foals were used to evaluate the effects of artificial rearing on growth. Seven foals were removed from their dams at 3 d of age and fed a reconstituted 26% crude protein (CP) milk replacer free choice for 1 mo, at which time ad libitum solid feeding began. Controls were weaned from their dams at 2 mo of age and fed a 21% CP concentrate ad libitum until the end of the trial. Variables measured during the 26-wk trial were live body weight, height at the withers and length of body from point of shoulder to point of hip. No significant differences were found between the two ...
Cao XZ, Lin YZ, Li L, Jiang CG, Zhao LP, Lv XL, Zhou JH.The threshold hypothesis of attenuated lentiviral vaccine considers that the type of host response to infections of lentiviruses depends on the viral load. To evaluate the correlation between viral loads of the attenuated vaccine strain of equine infectious anemia virus (EIAV) and their effects to induce protective immunity, longitudinal plasma viral loads in groups of horses inoculated with either an attenuated EIAV vaccine strain (EIAV(DLV125)) or sub-lethal dose of an EIAV virulent strain (EIAV(LN40)) were compared. Similar levels of plasma viral loads ranging from 10(3)-10(5) copies/mL wer...
Lorenzo PL, Liu IK, Illera JC, Picazo RA, Carneiro GF, Illera MJ, Conley AJ, Enders AC, Illera M.Epidermal growth factor (EGF) has been reported to promote different functions in mammalian ovaries, including oocyte maturation. The aim of the present study was to establish: that EGF influences oocyte maturation in ovine and equine, that a tyrosine kinase-dependent intracellular mechanism mediates EGF effect and, that EGF-R receptor is detectable in ovarian follicles by immunohistochemistry methods. Selected ovine and equine oocytes were aspirated from 2-5 mm (ovine) or 25 mm (equine) follicles and cultured in TCM 199 for 22 (ovine) or 36 hours (equine). They are then subjected to culture w...
Borgsteede FH, van Beek G.The prevalence of tapeworm infestations was investigated in 70 horses slaughtered in the period February 1994-July 1994. Most horses were half-breed, young (1.5-3 years), and in good condition. They were bought for slaughter by dealers on local markets, and their treatment history was therefore unknown. Tapeworm infestations were seen in 16 horses (23%). Fifteen (21%) had an infection with Anoplocephala perfoliata. One horse had a single specimen of Paranoplocephala mamillana. The average number of A. perfoliata was 45 and the highest number was 508.
Hofferer S, Duchamp G, Palmer E.Twelve anoestrous mares were treated with an intravaginal sponge containing 0.5 g allyl trembolone (Regumate; Roussel UCLAF, Paris) and 50 mg oestradiol benzoate for 7 days, followed by daily intramuscular (i.m.) injections of 25 mg crude equine pituitary extract (CEG), with (n = 6) or without (n = 6) 0.25 mg porcine growth hormone (pGH). No difference in ovarian response to this superovulation treatment was observed between the 2 groups (2.2 +/- 0.4 vs 2.3 +/- 0.4 ovulations per mare, respectively). CEG treatment was then combined with allyl trembolone (40 mg per os per day) and prolonged in ...
Recio P, Prieto D, Martínez MP, García P, Rivera L, Benedito S, Martínez AC, Sacristán AG, Orensanz LM, Hernández M.Our aim was to study the presence of noradrenergic nerves and to characterize the alpha-adrenergic receptors involved in the contractions to electrical field stimulation and to alpha-adrenergic agonists of the horse penile deep dorsal vein. Noradrenergic fibres were visualized by immunohistochemistry using an antibody against dopamine-beta-hydroxylase (DBH). For functional studies, the responses of the venous rings to electrical field stimulation and to alpha-adrenergic agonists (noradrenaline, phenylephrine and BHT 920) were studied in the absence and the presence of noradrenergic transmissio...
