Veterinary research in horses encompasses the study of diseases, health management, and medical treatments specific to equine species. This field investigates various aspects of horse health, including infectious diseases, metabolic disorders, and musculoskeletal conditions. Researchers focus on understanding the pathophysiology of equine ailments, developing diagnostic tools, and evaluating therapeutic interventions. The study of horse health also involves examining preventive measures such as vaccination protocols and nutritional management to promote overall well-being. This page collects peer-reviewed research studies and scholarly articles that explore the diverse areas of veterinary science related to horses, providing insights into disease mechanisms, treatment strategies, and advancements in equine healthcare.
Gehlen H, Marnette S, Rohn K, Kreienbrock L, Stadler P.Echocardiographic measurements have to be reliable and reproducible with only a low day to day variability for detecting pathological changes of left ventricular myocardial function in horses. The day dependent fluctuation margin represents an important indicator for the reproducibility of a method. To find out the day to day variability of echocardiographic parameter in healthy warmblood horses, in the present study repeated echocardiographic measurements at three consecutive days were carried out (at the same time and by the same examiner) at 11 untrained and 7 trained warmblood horses. The ...
Patton KM, McGuire TC, Hines MT, Mealey RH, Hines SA.Rhodococcus equi is an important cause of pneumonia in young horses; however, adult horses are immune due to their ability to mount protective recall responses. In this study, the hypothesis that R. equi-specific cytotoxic T lymphocytes (CTL) are present in the lung of immune horses was tested. Bronchoalveolar lavage (BAL)-derived pulmonary T lymphocytes stimulated with R. equi lysed infected alveolar macrophages and peripheral blood adherent cells (PBAC). As with CTL obtained from the blood, killing of R. equi-infected targets by pulmonary effectors was not restricted by equine lymphocyte all...
Quinn GC, Kidd JA, Lane JG.Previous studies of sinus surgery on standing horses have been based on techniques which utilise powered hand bone saws and preserve the bone flap, which was thought to be essential for a good cosmetic result. This report describes a simplified technique applied to the standing horse where the sinus flap construction used a large skull trephine and where the bone flap is necessarily discarded. Objective: To assess whether the modified standing frontonasal flap (SFF) surgery offers an effective method to investigate and/or treat sinunasal disorders in the horse. Methods: The case records of 60 ...
Robertson SA, Sanchez LC, Merritt AM, Doherty TJ.Commonly used analgesics (nonsteroidal anti-inflammatory agents, opioids and alpha2-agonists) have unwanted side effects. An effective alternative with minimal adverse effects would benefit clinical equine pain management. Objective: To compare the effect of lidocaine or saline on duodenal and rectal distension threshold pressure and somatic thermal threshold in conscious mature horses. Objective: Systemically administered lidocaine would increase somatic and visceral nociceptive thresholds. Methods: Lidocaine (2 mg/kg bwt bolus followed by 50 microg/kg bwt/min for 2 h) or saline was administe...
Dixon PM, Dacre I, Dacre K, Tremaine WH, McCann J, Barakzai S.Extraction of cheek teeth (CT) by the conventional repulsion technique requires general anaesthesia and carries a high rate of post operative complications. Consequently, an alternative method of extraction, i.e. orally in standing horses, was evaluated. Objective: The need for and risks of general anaesthesia could be avoided and post extraction sequelae reduced by performing extractions orally in standing horses. Methods: One hundred mainly younger horses (median age 8, range 2-18 years) with firmly attached CT that required extraction because of apical infections, displacements, diastemata,...
Smith MA, Walmsley JP, Phillips TJ, Pinchbeck GL, Booth TM, Greet TR, Richardson DW, Ross MW, Schramme MC, Singer ER, Smith RK, Clegg PD.Subchondral cystic lesions of the medial femoral condyle (SCMFC) are well documented in horses < or =3 years; arthroscopic debridement or enucleation of the cyst is currently the surgical treatment of choice. However, studies of occurence and outcome following surgery in older horses are lacking. Objective: To identify factors important in outcome for horses with SCMFC treated by arthroscopic debridement. Objective: Age of horse at presentation has a significant influence on return to work following arthroscopic treatment for SCMFC. Clinical and diagnostic findings are also significant with re...
Brommer H, Brama PA, Laasanen MS, Helminen HJ, van Weeren PR, Jurvelin JS.The concept of functional adapatation of articular cartilage during maturation has emerged from earlier biochemical research. However, articular cartilage has principally a biomechanical function governed by joint loading. Objective: To verify whether the concept of functional adaptation can be confirmed by direct measurement of biomechanical properties of cartilage. Objective: Fetuses have homogeneous (i.e. site-independent) cartilage with regard to biomechanical properties. During growth and development to maturity, the biomechanical characteristics adapt according to functional (loading) de...
Kakoi H, Hirota K, Gawahara H, Kurosawa M, Kuwajima M.Sex chromosome aberrations are often associated with clinical signs that affect equine health and reproduction. However, abnormal manifestation with sex chromosome aberration usually appears at maturity and potential disorders may be suspected infrequently. A reliable survey at an early stage is therefore required. Objective: To detect and characterise sex chromosome aberrations in newborn foals by the parentage test and analysis using X- and Y-linked markers. Methods: We conducted a genetic diagnosis combined with a parentage test by microsatellite DNA and analysis of X- and Y-linked genetic ...
Sandersen CF, Detilleux J, Delguste C, Pierard L, van Loon G, Amory H.High-dose dobutamine stress echocardiography has been shown to be cardiotoxic and arrhythmogenic in horses. However, the test may have benefit in practice as a pharmacological challenge of exercise without the treadmill being required. Objective: To investigate the effect of low-dose dobutamine on cardiac performance in ponies previously treated with atropine, in order to develop a pharmacological protocol that allows examination of the equine heart under stimulation. Methods: In 13 healthy Shetland ponies, heart rate (HR), stroke index (SI) and cardiac index (CI) were calculated from pulsed-w...
McGuigan MP, Walsh TC, Pardoe CH, Day PS, Wilson AM.Previous studies have implicated tension in the deep digital flexor tendon (DDFT) in the rotation of the distal phalanx (DP) after the breakdown of the dorsal laminae caused by laminitis. Howeveer, once the DP has rotated, the DDFT should become shorter, reducing the force it exerts on the DP. Objective: To compare DDFT force and ground reaction forces (GRFs) in normal ponies and ponies with rotation of the DP as a sequel to laminitis. Methods: Six normal ponies (Group 1) and 6 sound ponies with 6-13 degrees of rotation of the DP in relation to the dorsal hoof wall (Group 2) were assessed at t...
Simonen-Jokinen T, Pirie RS, McGorum B, Maisi P.Airway matrix metalloproteinases (MMPs) increase after endotoxin (LPS) exposure, but there are no reports describing dose-dependent increases or activation following exposure. Objective: To study matrix metalloproteinase-9 (MMP-9) and -2 (MMP-2) responses in bronchoalveolar lavage fluid (BALF) from heaves-susceptible and control horses following inhalation of hay dust suspension (HDS), LPS and Aspergillus fumigatus extract (AFE). Methods: Heaves-susceptible (n = 7) and control (n = 6) horses received inhalation challenges with 3 different doses of HDS and LPS. Heaves-susceptible horses (n = 6)...
Harvey SP, Minter JM.In this study, the subspecies differentiation of 25 isolates of Burkholderia mallei was attempted based on their ribotype polymorphisms. The isolates were from human and equine infections that occurred at various times around the world. DNA samples from each isolate were digested separately with PstI and EcoRI enzymes and probed with an Escherichia coli-derived 18-mer rDNA sequence to identify diagnostic fragments. Seventeen distinct ribotypes were identified from the combined data obtained with the two restriction enzymes. The results demonstrate the general utility of ribotyping for the subs...
Egerbacher M, Helmreich M, Probst A, König H, Böck P.Digital cushions were studied in horses with particular reference to vascularization, tissue constituents and matrix components. The cushions mainly resembled a network of coarse collagen bundles. The areas inbetween the bundles were replenished with loosely woven interstitial connective tissue, myxoid tissue, and fibrocartilage. Expected masses of fat lobules were missing: only solitary adipocytes or small groups of adipocytes were seen. Vascular supply to the cushions was remarkably poor. The mucinous myxoid matrix largely consisted of hyaluronan with little sulphated glycosaminoglycans. Myx...
Kumar P, Timoney JF.The stratified squamous epithelium of the lingual tonsil of five young horses was infiltrated with CD4 and CD8 positive cells, which were very numerous in the crypt reticular epithelium along with macrophages and IgGb and IgA positive cells. Lymphoid follicles of the lamina propria mucosae consisted of a parafollicular area, corona and germinal centre. The parafollicular area was populated by large numbers of CD4 and CD8 positive lymphocytes as well as macrophages, inter-digitating cells, and a few B-lymphocytes. The germinal centre contained mainly IgGb and IgG(T) positive cells, plasma cells...
Perkins NR, Reid SW, Morris RS.To investigate training location (horses trained in Matamata vs those trained at all other venues in New Zealand), and time period (1996-1997 and 1998-1999), while controlling for other horse- and race- or trial-related factors, as a means of assessing the possible impact of construction of a new training surface at the Matamata Racing Club on indirect measures of racehorse performance (number of starts, and failure to race within 6 months of any start). Methods: Multivariable logistic regression and poisson analysis were used to analyse data derived using a retrospective cohort approach. Mult...
Hoyt DF, Wickler SJ, Biewener AA, Cogger EA, De La Paz KL.The activity of muscles can be concentric (shortening), eccentric (lengthening) or isometric (constant length). When studying muscle function it is important to know what the muscle fascicles are actually doing because the performance of muscle is strongly influenced by the type of activity: force decreases as a function of shortening velocity during concentric contractions; force produced during eccentric contractions can be stronger than maximum isometric force, and force production is enhanced if a concentric contraction follows an eccentric phase. It is well known that length changes of mu...
Ineson AC, Rogers CW, Firth EC, Gee EK.To compare subjective and quantitative methods of assessing physeal swelling of the distal third metacarpal (Mc3) and metatarsal (Mt3) bones of Thoroughbred foals. Methods: The fetlocks of 16 Thoroughbred foals were filmed on five occasions over a period of 5 months and the video images were transferred to computer and digitised. The rate of change of each of the medial and lateral contours of the distal Mc3 and Mt3 bones was determined by calculating values for the second derivative of the contour. The degree of physeal swelling at the same site was subjectively assessed and allocated a grade...
Firth EC.Detecting changes in bone during growth, training, rest from competition (spelling), and disease in horses requires imaging techniques that have a high level of accuracy and precision. Currently, most imaging techniques used in horses do not possess such characteristics and are more suitable for detecting end-stage disease than subtle changes. Some are incapable of detecting changes in bone size. Non-planar techniques should be used for estimating or determining bone strength. This review outlines available imaging techniques and shows why cross-sectional procedures are required to accurately ...
Kolm G, Gemeiner M, Deichsel K, Budik S, Aurich J, Aurich C.The failure of clearance mechanisms in the mare's uterus results in persistent inflammation and is considered a major cause of subfertility. Eighteen mares, of which three were susceptible to endometritis and four had been ovariectomised, underwent charcoal clearance testing to evaluate their clearance mechanisms. This consisted of installing 500 mg of charcoal (particle size 4 to 90 microm) added to 50 ml of phosphate-buffered saline (PBS) into the uterus. Forty-eight hours later the uterus was flushed out with 0.0012 per cent methylene blue in 50 ml of PBS for determination of the diluting f...
Firth EC, Rogers CW, Perkins NR, Anderson BH, Grace ND.This is the first in a series of papers reporting studies in 2-year-old Thoroughbred racehorses that aimed to determine the response of musculoskeletal tissues to early training on grass and sand racetracks. In this paper, the experimental set-up of the whole study is described, and nutritional, workload, and clinical, radiographic and pathological outcomes are reported, including semi-quantitative assessment of macroscopic changes in articular cartilage. Methods: The study group comprised 14 two-year-old Thoroughbred fillies reared entirely at pasture. Of these, seven were selected by a licen...
Turkstra JA, van der Meer FJ, Knaap J, Rottier PJ, Teerds KJ, Colenbrander B, Meloen RH.Immunization against gonadotrophin releasing hormone (GnRH) was studied as an alternative for the commonly used surgical castration in stallions. Two GnRH vaccines comprising non-mineral oil adjuvants were evaluated for their potential to induce high antibody titers directed against GnRH and subsequent effects on reproductive characteristics. Twelve sexually mature male hemicastrated Shetland ponies were assigned to three groups. Group 1 and 2 were injected with 1mg peptide equivalent of G6k-GnRH-tandem-dimer conjugated to ovalbumin (OVA) in CoVaccine HT adjuvant (GnRH/CoVaccine) and in Carbop...
Rogers CW, Firth EC.To identify the magnitude and sources of error involved in simply quantifying the workload of a group of Thoroughbred racehorses in training. Methods: Data were obtained from seven 2-year-old fillies trained for 13 weeks on sand and grass tracks at various cantering velocities, and at the gallop in the last 4 weeks. Four fillies completed training and comprised a 'high exercise intensity' subgroup; three fillies did not complete all gallops due to lameness or injury and comprised a 'medium exercise intensity' subgroup. The trainer recorded the distance, time, track used, and subjective gait (S...
Lindner A, Dag S, Marti-Korff S, Quiroz-Rothe E, López Rivero JL, Drommer W.The collection of muscle samples in horses to estimate their performance potential, adaptations to training and diagnosis of exertional myopathies is of increasing interest. This study was designed to examine whether repeated biopsying of the gluteus medius muscle at 7 week intervals alters morphology and muscle fibre variables in the sampling area. The gluteus had been biopsied 3 times previously, each biopsy separated by a 7 week interval. Seven weeks after the last biopsy, this study was initiated. Percutaneous needle biopsies were taken from left and right muscles at 2 depths (2 and 6 cm) ...
Weaver RE, Sharif M, Livingston LA, Andrews KL, Fuller CJ.The objective of this study was to assess whether macroscopically normal articular cartilage taken from joints containing focal osteoarthritic lesions is histologically similar to articular cartilage taken from macroscopically normal joints. Metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints were obtained from 10 horses following euthanasia. Gross articular cartilage damage was scored and the cartilage assigned to one of two groups: (1) macroscopically normal cartilage from normal joints (control) and (2) macroscopically normal cartilage from diseased joints in wh...
Kuttler KL, Goff WL, Gipson CA, Blackburn BO.Both the complement-fixation test (CFT) and the indirect fluorescent antibody test (IFAT) were conducted on weekly serum samples from nine Arab geldings for 28 days before and 256 days after their exposure to Babesia equi of European origin. On an average the IFAT became positive 8 days before the CFT and showed higher relative serum titer increases. Both test procedures successfully detected infection and neither showed an appreciable drop in titer during this time frame, with the exception of the CFT, which showed a transient drop immediately following treatment with imidocarb. A test conduc...
The Journal of physiologyFebruary 9, 2006
Volume 572, Issue Pt 1 155-164 doi: 10.1113/jphysiol.2006.105635
O'Connor SJ, Ousey JC, Gardner DS, Fowden AL, Giussani DA.This study investigated, in vivo, the mechanisms underlying the development of cardiovascular function in the horse fetus, with particular relevance to baroreflex function and hind limb vascular arterial reactivity to constrictor agonists. Under general anaesthesia, vascular catheters were inserted and a Transonic flow probe was implanted around one of the metatarsal arteries of 13 horse fetuses, either at 0.6 of gestation (n= 6) or at 0.9 of gestation (n= 7, term approximately 335 days). At least 5 days after surgery, pressor, vasoconstrictor and cardiac chronotropic responses to exogenous bo...
Liang FT, Granstrom DE, Timoney JF, Shi YF.We report a simple, economical, and efficient protocol for protein purification from cells. First, proteins of cell lysates were separated by standard sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and electroblotted to protein-blotting membrane. The blots were stained with Coomassie blue or developed by immunoblotting to visualize specific proteins. The bands corresponding to those visible by immunoblotting were excised from the dye-stained blots and subjected to isoelectric focusing. The focused gel was stained with Coomassie blue. Finally, the stained bands were excise...
Tóth F, Schumacher J.Repair of hernias of the abdominal wall of horses is often augmented by inserting a prosthetic mesh. In this review, we describe the various characteristics of prosthetic meshes used for hernia repair and present 2 systems that are used by surgeons in the human medical field to classify techniques of prosthetic mesh herniorrhaphy. Both of these classification systems distinguish between onlay, inlay, sublay, and underlay placements of mesh, based on the location within the abdominal wall in which the prosthetic mesh is inserted. We separate the published techniques of prosthetic mesh herniorrh...
Dodds L, Knight L, Allen K, Murrell J.To investigate the effect of postsurgical pain on the performance of horses in a novel object and auditory startle task. Methods: Prospective clinical study. Methods: Twenty horses undergoing different types of surgery and 16 control horses that did not undergo surgery. Methods: The interaction of 36 horses with novel objects and a response to an auditory stimulus were measured at two time points; the day before surgery (T1) and the day after surgery (T2) for surgical horses (G1), and at a similar time interval for control horses (G2). Pain and sedation were measured using simple descriptive s...
Blanchard A, Barr EM, Gilger BC.The purpose of this case series is to evaluate the use of spectral domain optical coherence tomography (SD-OCT) imaging in equine corneal disease to demonstrate the feasibility, diagnostic effectiveness, and limitations of this imaging modality. Methods: Retrospective study: Handheld SD-OCT (Envisu, Bioptigen Inc, Morrisville, NC) was used for high-resolution imaging of horses with corneal disease presenting to the North Carolina State University Equine Ophthalmology Service from 2013 to 2018. Results: Fourteen horses were included in this study, including six horses with corneal ulceration, t...
Carpenter EM, Hendrickson DA, James S, Franke C, Frisbie D, Trostle S, Wilson D.To determine a hand-tied ligature knot configuration, suture size, and suture type that would be an acceptable substitute to commercially available ligature knots for use in equine laparoscopic surgery. Methods: Three-factor ANOVA with the fixed effects being suture type, suture size, and knot type. The dependent variable was ligature security (load to failure). Methods: Commercially available Endoloop and 4 hand-tied slipknot ligatures were compared with a 4-layer square knot. The hand tied ligature knots tested were the 4S modified Roeder knot, the Brooks knot, the modified Roeder knot, and ...
Firth EC, Greydanus Y.The talus and proximal and distal epiphysis of the humerus, radius, femur, tibia and distal metacarpus of 20 foals aged 0 to 150 days were obtained at necropsy and sawn sagittally into slabs 4 to 8 mm thick. The thickness of the cartilage (articular cartilage and unossified epiphyseal cartilage) was measured in three to five places in each slab, using a sliding calliper. In most epiphyses, the site, or sites, of thickest cartilage was constant in all foals examined. The difference between thickest and thinnest cartilage within one epiphysis was greatest in distal femora and least in distal met...
Baird AN, Cohen ND, Taylor TS, Watkins JP, Schumacher J.During a 5-year period, renosplenic entrapment of the large colon was diagnosed in 57 horses referred to the Texas Veterinary Medical Center. The signalment of and clinical signs of disease in these horses were compared with such variables in 200 horses referred for other types of colic. Findings did not support a male gender predilection for this disease, as was previously reported. The case survival rate was 93% for this group of horses. Fourteen of the horses were treated nonsurgically by rolling them clockwise while they were under general anesthesia. Data supported the safety and efficacy...
Berhane Y, Elliott J, Bailey SR.Haemodynamic disturbances leading to ischaemia and reperfusion injury of the digit are thought to be involved in the pathophysiology of acute equine laminitis. Identification of physiological regulators of blood flow through the equine digit is important in identifying factors, which may predispose animals to laminitis. A method was developed to assess endothelium-dependent responses of the isolated Krebs-perfused equine digit by co-administration of 5-hydroxytryptamine (5-HT) with vasodilator agents, carbachol (CCh), bradykinin (BK) and substance P (SP). Bolus co-administration of CCh (0.02-2...
Leise BS, Fugler LA, Stokes AM, Eades SC, Moore RM.To determine the magnitude and duration of effects of acepromazine administered intramuscularly (IM) on digital and systemic hemodynamic variables in clinically healthy horses. Methods: Experimental study. Methods: Healthy adult horses (n=12). Methods- An ultrasonic Doppler flow probe was surgically implanted around the medial palmar digital artery before the study. Catheters were inserted in the transverse facial artery, lateral palmar digital artery, and jugular vein. A treatment group (n=6) was administered 0.04 mg/kg body weight of acepromazine IM; control horses (n=6) were administered an...
Bowling AT, Gordon L, Penedo MC, Wictum E, Beebout J.We describe a method for agarose IEF under acid conditions in which a single gel can be used to diagnose from equine red cell lysates genetic variants for carbonic anhydrase (CA) and catalase (Cat). Family and population data for 4801 horses of 27 breeds and seven trap sites of Great Basin feral horses are presented to support the presence of a sixth CA allele, CAE, which has been recognized previously, but not described by published data. Allelic frequencies for the two systems suggest it may be appropriate to use this gel for parentage verification programmes or to obtain population data for...
Davis SL, Graf M, Morrison CA, Hall TR, Swift PJ.The chemical nature and variations in serum concentrations of growth hormone binding protein (GHBP) from humans, rabbits, and rodents have been reported. To date little is known about the GHBP of domestic animals. Therefore, we initiated these studies to determine whether a serum GHBP was present in domestic animals and to purify the binding protein (BP) from serum of selected species. Using a dextran-coated charcoal separation assay, specific growth hormone (GH) binding was demonstrated in ovine, bovine, chicken, human, goose, porcine, and equine serum (listed in sequence from lowest to highe...
Feugang JM, Ishak GM, Eggert MW, Arnold RD, Rivers OS, Willard ST, Ryan PL, Gastal EL.Despite the progress in assisted reproductive techniques, there is still a lack of rapid and minimally invasive in situ approaches for further enhancements of female fertility. Therefore, we synthesized clinically relevant liposome nanoparticles for ovarian intrafollicular injection to allow in vivo cellular imaging for future drug delivery, using the mare as an animal model. Ovarian follicles of living mares were injected in vivo with fluorescently labeled liposomes. Samples of the follicular wall (mural granulosa, theca interna, and theca externa), granulosa cells, and follicular fluid wer...
MacNicol JL, Pearson W. organ culture can provide insight into isolated mucosal responses to particular environmental stimuli. The objective of the present study was to investigate the impact of a prolonged culturing time as well as the addition of acidic gastric fluid into the environment of cultured gastric antral tissue to evaluate how altering the commonly used neutral environment impacted tissue. Furthermore, we aimed to investigate the impact of G's Formula, a dietary supplement for horses, on the secretion of gastrin, interleukin1-beta (IL-1β), and nitric oxide (NO). These biomarkers are of interest due to ...
Tarr MJ, Olsen RG, Krakowka GS, Cockerell GL, Gabel AA.Erythrocyte rosette (ER) formation of equine peripheral blood lymphocytes (PBL) was characterized. Guinea pig and, to a lesser extent, human erythrocytes formed ER; cat, cow, dog, hamster, mouse, rat, and sheep erythrocytes showed negligible rosetting properties. Conditions of the assay were varied to determine which procedure allowed the largest percentage of rosette formation. The PBL from 20 normal horses were then assayed, averaging 38 +/- 2% ER. To characterize the erythrocyte receptor as being on T or B cells, equine thymocytes from 6 foals were assayed; the thymocytes formed an average ...
Tyrnenopoulou P, Fthenakis GC.Antibiotic administration is a standard therapeutic practice for the treatment of reproductive disorders of equids. This might lead to undesirable microbial imbalance and could favour the acquisition of antibiotic resistance. Therefore, it is imperative for clinicians to understand patterns of antibiotic resistance when considering and developing treatment regimes. Continued engagement of clinicians with novel alternative approaches to treat reproductive infections would be essential in order to address this rising threat within the One Health perspective. The objectives of the present review ...
Riera FL, Roldán JE, Espinosa JM, Fernandez JE, Ortiz I, Hinrichs K.Embryo biopsy for fetal sexing has clinical application, but few reports are available of its use within an active embryo transfer program. We evaluated results on biopsy of 459 embryos over one breeding season. There were no significant differences in pregnancy rate between biopsied and non-biopsied embryos (72% vs 73%) or for biopsied embryos recovered at the centre (73%) compared with those shipped overnight (72%). However, the pregnancy rate decreased significantly in shipped embryos biopsied ≥20h after collection. Overall, 86% of biopsies provided a sex diagnosis. The likelihood of a po...
Rutllant J, Meyers SA.It is generally accepted that spermatozoa become functionally mature during epididymal transit. The objective of this study was to determine whether the cellular location of equine PH-20 is modified during epididymal transit and, if so, the mechanism for such modification. Sperm were isolated from caput and cauda epididymal regions from stallions undergoing castration (n = 7) and used as whole sperm cell or subjected to nitrogen cavitation for isolation of plasma membrane proteins. Both caput and cauda sperm and sperm protein extracts were subjected to N-deglycosylation, O-deglycosylation, or ...