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Topic:Comparative Study
Comparative studies in equine research involve the systematic analysis of different horse breeds, management practices, or physiological responses to identify variations and similarities. These studies are instrumental in understanding how different factors influence health, performance, and behavior in horses. Common areas of comparison include genetic traits, nutritional requirements, disease resistance, and response to training. By evaluating these differences, researchers can develop targeted strategies for breeding, healthcare, and training. This page aggregates peer-reviewed research studies and scholarly articles that focus on the methodologies, findings, and implications of comparative studies in the context of equine science.
Breed differences in circulating equine relaxin. Equine relaxin has been previously determined in a small number of pregnant Thoroughbred mares. To better define the normal pregnancy pattern of relaxin, the current study reports on a much larger number of mares. It also was designed to determine if all equids have the same gestational pattern of relaxin secretion. Plasma samples were collected weekly in 24 Standardbred mares, every 7-10 days in 10 pony mares, and daily in late pregnancy from 16 burros. Standardbreds had higher concentrations of relaxin than that reported for Thoroughbreds during most of gestation and did not exhibit the midp...
Influence of age on fibre type characteristics in the middle gluteal muscle of Andalusian foals. 34 Andalusian foals of both sexes were divided into three age-groups (A = mean age 1 month, B = 7 months, C = 14 months). Samples of the right m. gluteus medius were stained for m-ATPase and NADH-TR in order to determine fibre type composition and size as well as the relative area occupied by each type. Results revealed no statistically significant variation in the proportion of type I fibre among the three age-groups. Significant differences were recorded, however, for type II fibres; an increase in the proportion of IIA fibres was accompanied by a decrease in IIB ones, the difference being m...
Histopathological changes in the coeliaco-mesenteric ganglia of horses with ‘mal seco’, a grass sickness-like syndrome, in Argentina. 'Mal seco' is a grass sickness-like syndrome of horses in Argentina. A histopathological study was made of the coeliaco-mesenteric ganglia of four horses with 'mal seco' and of four horses that died from other causes. The severity and extent of the lesions found in the horses with 'mal seco' was greatest in the two with the shortest clinical course. Degenerative changes consisted mainly in the loss of Nissl substance, cytoplasmic vacuoles, neuronophagia, intercellular and intracytoplasmic eosinophilic bodies, and pyknotic and eccentric nuclei. The coeliaco-mesenteric ganglia of the control hor...
Interconversion of E and S isoenzymes of horse liver alcohol dehydrogenase. Several residues contribute indirectly to catalysis. The E and S isoenzymes of horse liver alcohol dehydrogenase differ by 10 amino acid residues, but only the S isoenzyme is active on 3 beta-hydroxysteroids. This functional difference was correlated to the differences in structures of the isoenzymes by characterizing a series of chimeric enzymes, which could represent intermediates in the evolution of catalytic activity. Deletion of Asp-115 from the E isoenzyme created the E/D115 delta enzyme that is active on steroids. The deletion alters the substrate binding pocket by moving Leu-116, which sterically hinders binding of steroids in the E isoe...
A comparative study of the metabolic effort expended by horse riders during a jumping competition. The three main Olympic horse riding disciplines are dressage, jumping, and three-day eventing (including dressage, cross country and jumping). In the jumping discipline (obstacle race), the 'team' (horse rider) is judged under the different conditions that might take place in a varied run. The horse is expected to show power and ability; the rider must show riding skill and good physical condition. However, the different conditions encountered by the rider during competition (duration of event, continuous isometric working level, especially in the inferior trunk, lead us to consider the need f...
Histologic features of the carotid artery trifurcation in thoroughbreds. The common, external, and internal carotid and occipital arteries were examined histologically at the trifurcation of the common carotid arteries in 13 Thoroughbred foals (0 to 30 days old) and 64 Thoroughbred adults (2 to 4 years old). Calcification in the media of the common carotid and external carotid arteries was observed in 3 of the 13 foals and in 30 of the 64 adult horses. Calcification resembled that seen in Mönckeberg's arteriosclerosis in human beings, the cause of which is unknown.
A two year, prospective survey of equine colic in general practice. The records of 200 colic episodes, collected prospectively, over a two year period, from first opinion cases, were analysed and compared with a control sample selected at random from the same population. Analysis by colic type revealed 72% spasmodic/undiagnosed; 7% surgical; 5.5% flatulent; 5% pelvic flexure impactions; 9.5% other implications and 1% colitis. A possible predisposing cause was identified in 43% of the spasmodic/undiagnosed cases. The total incidence of colic in each age group showed no statistically significant differences from the control population. Stallions were significant...
Suspensory apparatus prosthesis in the horse. Part 1: In vitro mechanical properties. Mechanical properties of equine suspensory apparatus preparations and three braided synthetic prostheses were evaluated in vitro. Force versus displacement plots and failure modes were recorded from single load-to-failure testing in 18 cadaver limbs before and after replacement of each suspensory apparatus with a prosthesis. Mean load at failure, energy to failure, and stiffness values of polytetrafluoroethylene (PTFE) prostheses were lower than those of the suspensory apparatus and aramid prosthesis. The PTFE prosthesis failed by elongation or rupture of the prosthesis. Mechanical properties ...
A comparison between the nutritive value of short-cutting cycle, high temperature-dried alfalfa and timothy hay for horses. The objective was to evaluate the nutritive value of short-cutting cycle, high temperature-dried (SCCHTD) alfalfa compared to timothy hay. This was achieved by carrying out 4 x 4 Latin Square digestibility trial using 4 Thoroughbred (one three-quarter Thoroughbred) horses (mean liveweight, 531 kg). The four dietary treatments were 0AA (timothy hay only), 33AA (0.33 alfalfa: 0.67 timothy hay), 67AA (0.67 alfalfa: 0.33 timothy hay) and 100AA (alfalfa only). Digestibility data were obtained by using acid-insoluble ash to estimate apparent digestibility coefficients of nutrients. Rate of passage o...
The ‘natural’ hybrid haemoglobin from mule. Interrelationships with its parent haemoglobins from horse and donkey. The equilibrium O2-binding properties of the hybrid haemoglobin (Hb) present in vivo in erythrocytes from mule and of its parent Hbs from horse and donkey were compared with special reference to the effect of heterotropic ligands such as Cl-, D-glycerate 2,3-bisphosphate (DPG) and inositol hexakisphosphate. All these Hbs display a decreased effect by polyphosphates, confirming that what has been observed for horse Hb [Giardina, Brix, Clementi, Scatena, Nicoletti, Cicchetti, Argentin & Condò (1990) Biochem. J. 266, 897-900] is common to other equine species, at least from a qualitative sta...
Identification and partial purification of serum growth hormone binding protein in domestic animal species. 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...
Characterization of a trypsin inhibitor from equine urine. A trypsin inhibitor was isolated from pregnant mares' urine by adsorption on bentonite and elution with aqueous pyridine followed by batch DEAE-cellulose treatment and column chromatography. Final purification to an electrophoretically homogenous glycoprotein was achieved by gel permeation chromatography. This equine urinary trypsin inhibitor (E-UTI) is acid- and heat-stable, has a molecular weight of 22 to 23 kDa, an isoelectric point of 4.55, forms a 1:1 molar complex with trypsin and has serine as its N-terminal amino acid. The N-terminal amino acid sequence of this protein is almost identi...
Pulmonary blood flow distribution in anesthetized ponies. Results of recent investigations in humans and dogs indicate that gravity-independent factors may be important in determining the distribution of pulmonary blood flow. To further evaluate the role of gravity-independent factors, pulmonary blood flow distribution was examined using 15-microns radionuclide-labeled microspheres in five prone ponies over 5 h of pentobarbital sodium anesthesia. The ponies were killed, and the lungs were excised and dried by air inflation (pressure 45 cmH2O). The dry lungs were cut into transverse slices 1-2 cm thick along the dorsal-ventral axis, parallel to gravit...
[The effect of storage time and temperature on the activity of glutathione peroxidase in plasma and whole blood of horses]. The influence of temperature and duration of storage on glutathione peroxidase (GSH-Px) activity in plasma and whole blood samples of horses was investigated. Furthermore the relationships between the GSH-Px activities in plasma and whole blood as well as the GSH-Px values related to hematocrit and the hemoglobin content of the blood samples of 93 different horses were calculated. At 20-22 degrees C, the GSH-Px activity in plasma and whole blood samples remained stable over at least three days while it was reduced by 38% and 65% after 2 and 3 days, if the whole blood samples were kept stored a...
Arthrographic analysis of communication between the tarsometatarsal and distal intertarsal joints of the horse. The intra-articular anatomy of 103 equine tarsi was studied by contrast radiography with image intensification and computerized tomography. There was communication between the tarsometatarsal and distal intertarsal joints in 21 of 55 (38%) interpretable tarsometatarsal arthrograms, and in 11 of 48 (23%) interpretable distal intertarsal arthrograms. The difference was not significant. The volume of contrast agent and the pressure of injection did not correlate with communication. Forced injection caused subcutaneous leakage of contrast medium but not communication. Communication occurred via th...
Development of lymphocyte blastogenic response in the neonatal period of foals. The blastogenic response of lymphocytes and serum concentration of cortisol from eighteen foals were evaluated during various stages of the neonatal period. The results of blastogenic responses were expressed by a stimulation index (SI). Blastogenic response to three mitogens was lowest at birth (PHA: 1.17 +/- 0.02, Con A: 1.11 +/- 0.05 and PWM: 1.02 +/- 0.01), then increased gradually with slight variations postpartum. The serum concentration of cortisol was highest at birth (44.0 ng/ml) and decreased rapidly to 19.3 ng/ml within 1 week postpartum, and then was maintained at this level. The h...
[Comparative plasmid profile analysis of Salmonella typhimurium var. Copenhagen strains from a Salmonella outbreak in hospitalized horses]. From April 1990 through June 1991 clinical salmonellosis and asymptomatic faecal excretion of Salmonella spp. were seen in hospitalized horses at two veterinary hospitals. 76 Salmonella strains from hospitalized horses and 18 strains from horses without any clinical contact were characterized by serotyping and plasmid profile analysis. From April 1990 through January 1991 97.8% of the hospitalized horses were infected with strains of S. typhimurium var. Copenhagen, which were closely related according to their similar plasmid patterns. Other strains of S. typhimurium var. Copenhagen and seroty...
Evaluation of peritoneal fluid following intestinal resection and anastomosis in horses. Postoperative abdominal fluid changes were compared in 2 groups of horses; those undergoing double small-colon resection and anastomosis (n = 10) and those undergoing exploratory celiotomy alone (n = 5). Peritoneal fluid was collected before surgery and on postoperative days 1, 3, 5, and 7. Total and differential nucleated cell counts, RBC numbers, and total protein and fibrinogen concentrations were evaluated. In both groups, all values were significantly higher than normal on the first postoperative day (after small-colon resection and anastomoses, WBC = 130,350 +/- 23,310 cells/microliters,...
A comparison of injectable anaesthetic regimens in mules. Three combinations of injectable anaesthetic agents were compared in nine adult mules. The combinations were xylazine/ketamine (X/K), xylazine/butorphanol/ketamine (X/B/K), and xylazine/tiletamine-zolazepam (X/T). Measured variables were heart rate, respiratory rate, systolic blood pressure, arterial blood pH, PCO2 and PO2, recumbency time and number of attempts to stand. Quality of induction and recovery, muscle relaxation and response to stimulus were evaluated subjectively. Recumbency time was significantly (P < 0.05) longer with X/B/K and X/T than with X/K. Mules required significantly mor...
Intradermal testing of horses with chronic obstructive pulmonary disease and recurrent urticaria. Six horses with chronic obstructive pulmonary disease (COPD) and 8 horses with recurrent urticaria were skin tested with 67 extracts from 58 allergens, including pollens, epidermals, cultivated farm plants, dusts, molds, and insects. Reactions were evaluated 3 times over a 24-hour period immediately after the injections. Results were compared with those obtained from 11 clinically normal horses. All horses had positive skin test reactions. Significant differences was evident between horses with COPD and clinically normal horses for only 3.0% of the possible extract reactions, and between horse...
N-acetylation and C-terminal proteolysis of beta-endorphin in the anterior lobe of the horse pituitary. beta-Endorphin is post-translationally processed to both N-acetylated and C-terminally shortened derivatives in the anterior lobe of the horse pituitary, a processing pattern qualitatively different from that of the rat and virtually every other mammalian species. Thus, separation of the molecular forms of beta-endorphin using gel filtration and ion exchange chromatography showed that the horse anterior lobe primarily contains beta-endorphin-1-31 and N-acetyl-beta-endorphin-1-27 along with smaller amounts of beta-lipotropin, beta-endorphin-1-27, and N-acetyl-beta-endorphin-1-31 and -1-26, in c...
Analysis of immediate-early transcripts of equine cytomegalovirus. Equine cytomegalovirus (ECMV) contains a linear, double-stranded DNA genome composed of a 146-kbp unique region flanked by a pair of 18-kbp direct repeat (DR) sequences at the termini. Cycloheximide, actinomycin D, and phosphonoacetic acid were applied to infected cell cultures to divide viral transcription into immediate-early (IE), early, and late phases. Eight IE transcripts were identified and mapped to two regions (I and II) of the viral genome. Two of these IE RNAs (13.0 and 5.5 kb in size) were transcribed from region I, which is located within the DR regions; these IE genes are diploid...
A review of the primary dysautonomias of domestic animals. Primary dysautonomias appear to be the result of initial damage to the protein synthetic pathway of a specific neuronal population, but despite detailed morphological study of several species there is, as yet, no indication of the precise lesion or the nature of the causal agent. The very marked similarities between the species with regard to lesion type, distribution, the age group affected and the geographical restrictions of occurrence would suggest a very similar, if not common, aetiology. There is no explanation, however, for the 70 year gap between its appearance in horses and its subseq...
Allometric relationships of cell numbers and size in the mammalian lung. Allometric studies have shown that lung volume, alveolar surface area, and diffusing capacity increase proportionally with body weight across a broad range of mammalian species. Changes in the number of cells and in average cell size and surface areas with increasing body weight have not been defined. We speculated that cell size is determined more by cell function than by species and body weight. To test this hypothesis, nine species ranging in size from shrew (2 to 3 g) to horse (510 kg) were studied. Random sites from the distal alveolar region of each species were analyzed using morphometr...
Species richness in helminth communities: the importance of multiple congeners. Using data sets derived from published literature, the contribution of congeneric species to helminth component community richness is evaluated. Consideration of the frequency distribution of congeners in relation to host and parasite groups reveals that the distributions are unimodal, that singletons are the commonest class and that the frequency of occurrence of congeners decreases with increasing number of species per genus. Congeners may be found in any group of hosts or parasites, but are more common amongst cestodes of aquatic birds. Two patterns of occurrence of congeneric species are r...
A comparison of injectable anaesthetic regimens in Mammoth asses. Xylazine (1.1 mg/kg body weight [bwt])-ketamine (2.2 mg/kg bwt) (X/K) anaesthesia was evaluated, in nine Mammoth asses, for effectiveness and compared with two other injectable anaesthetic combinations: xylazine (1.1 mg/kg bwt)-butorphanol (0.044 mg/kg bwt)-ketamine (2.2 mg/kg bwt) (X/B/K); and xylazine (1.1 mg/kg bwt)-tiletamine-zolazepam (1.1 mg/kg bwt) (X/T). All drugs were given intravenously (i.v.). Heart rate, respiratory rate, systolic blood pressure, arterial blood pH, PCO2, PO2, recumbency time and number of attempts to stand were measured. Quality of induction and recovery, muscle re...
Evidence for two serotype G3 subtypes among equine rotaviruses. Ten cultivable equine rotavirus isolates, two of North American, six of British, and two of Irish origin, were compared with standard rotavirus strains and with each other by cross neutralization, neutralization with a panel of monoclonal antibodies (MAbs), hybridization to a simian rotavirus (SA-11) VP7 gene probe, and reaction with rotavirus subgrouping and serotyping MAbs in enzyme-linked immunosorbent assays. Six isolates, two of which had previously been serotyped as G3 by other workers, were found to be serotype G3; one was confirmed to be G5, and three were not related to serotypes G1 t...
Sequence analysis of the equine H7 influenza virus haemagglutinin gene. The nucleotide sequences of ten haemagglutinin genes of representative H7N7 equine influenza viruses isolated between 1956 and 1977 have been determined by primer extension sequencing. Their nucleotide and deduced amino acid sequences demonstrate a high degree of homology. These equine viruses can be divided into two distinct subgroups, the prototype-like, and a group comprising the early American isolates and the remaining equine viruses. The equine H7 haemagglutinins form a quite distinct group compared to H7 haemagglutinins isolated from other species. Each of these equine H7 haemagglutinin...
