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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.
The A system of horse erythrocyte alloantigens: a new allele and another look at factor Ae. Family data are presented for a new allele (Aabdg) in the A system of horse erythrocyte alloantigens which includes factors Aa and Ab traditionally thought to be products of allelic genes. Evidence for incorrect assignment of the codominant factor Ae in the presence of Ab and Ac and the absence of Aa is discussed.
Iodide-induced inhibition of adenylate cyclase activity in horse and dog thyroid. The characteristics of the iodide-induced inhibition of cyclic AMP accumulation in dog thyroid slices have been previously described [Van Sande, J., Cochaux, P. and Dumont, J. E. (1985) Mol. Cell. Endocrinol. 40, 181-192]. In the present study we investigated the characteristics of the iodide-induced inhibition of adenylate cyclase activity in dog and horse thyroid. The inhibition of cyclic AMP accumulation by iodide in stimulated horse thyroid slices was similar to that observed in dog thyroid slices. The inhibition was observed in slices stimulated by thyroid-stimulating hormone, cholera tox...
[Sperm received in shipment versus fresh sperm in relation to fertilization results]. The conception rates of semen intended for shipment and those of recently obtained semen are compared in the present paper. Conception rates using recently obtained semen were significantly superior to those obtained with semen intended for shipment. A number of factors to which this difference could be due are briefly discussed.
Defective thymocyte maturation in horses with severe combined immunodeficiency. Six monoclonal antibodies, designated EqT2, EqT3, EqT6, EqT7, EqT12, and EqT13, which identify T lymphocyte antigens present at different stages of T cell maturation were used to examine T lymphocyte development in foals with severe combined immunodeficiency (SCID). Flow microfluorimetry demonstrated the presence of EqT12+ and EqT13+ prothymocytes and a few phenotypically mature EqT2+ and EqT3+ thymocytes within the thymic remnants of SCID foals. However, very few EqT6+ and EqT7+ resident cortical thymocytes were detected. The near absence of EqT6+ and EqT7+ cortical thymocytes was confirmed b...
Reconstituted and native iron-cores of bacterioferritin and ferritin. The structural and magnetic properties of the iron-cores of reconstituted horse spleen ferritin and Azotobacter vinelandii bacterioferritin have been investigated by high-resolution transmission electron microscopy, electron diffraction and Mossbauer spectroscopy. The structural properties of native horse spleen ferritin, native Az. vinelandii, and native and reconstituted Pseudomonas aeruginosa bacterioferritins have also been determined. Reconstitution in the absence of inorganic phosphate at pH 7.0 showed sigmoidal behaviour in each protein but was approximately 30% faster in initial rate f...
Eumycotic mycetoma: review and report of a cutaneous lesion caused by Pseudallescheria boydii in a horse. A cutaneous mass (1.5 cm in diameter) was removed from the head of a horse and was diagnosed histologically as eumycotic mycetoma. Immunofluorescence, performed on formalin-fixed, paraffin-embedded tissue, identified Pseudallescheria boydii as the etiologic agent. Findings from earlier reports of eumycotic mycetoma were compared with those of this horse.
Plasma lysozyme activity of Polish primitive horses under physiological conditions and in experimental fever. The normal level of plasma lysozyme of 9 Tarpane-like horses was 0.922pg/ml. This was
calculated from determinations performed 5 times in a period of 14 months. Observations on the
normal plasma level of lysozyme in the horse revealed marked variations in individual animals, as well
as in the whole group and in the mean values calculated for individual horses. The model for the
subsequent studies was an experimental fever evoked by the administration of E. colz LPS in a dose of
0.1 pg/kg body weight. Blood samples from the jugular vein were taken just before LPS injection, and
then for 8...
Role of the host immune response in selection of equine infectious anemia virus variants. Equine infectious anemia virus was isolated from peripheral blood leukocytes collected during two early febrile cycles of an experimentally infected horse. RNase T1-resistant oligonucleotide fingerprint analyses indicated that the nucleotide sequences of the isolates differed by approximately 0.25% and that the differences appeared randomly distributed throughout the genome. Serum collected in the interval between virus isolations was able to distinguish the isolates by membrane immunofluorescence on live cells. However, no neutralizing antibody was detected in the interval between virus isola...
Comparison of Ham’s F10 with CO2 or Hepes buffer for storage of equine embryos at 5 C for 24 H. Forty equine embryos collected 7 d post-ovulation were stored at 5 C for 24 h in one of two culture media (n = 20/group): 1) Ham's F10 + 10% heat-treated fetal calf serum (FCS) buffered by gassing with 5% CO2, 5% O2 and 90% N2 and 2) Ham's F10 + 10% FCS with Hepes buffer (25 mM). Embryos cultured in Ham's F10 + CO2 maintained a better quality score and had a larger average increase in diameter (+34.8 micron) than embryos stored in Hepes buffered Ham's F10 (-10.2 micron). Embryos were transferred surgically into recipient mares that ovulated -3 to +1 d in relation to the donor mare. Twenty embr...
Plasma, red blood cell, total blood, and extracellular fluid volumes in healthy horse foals during growth. During the growth interval encompassing age 2 days through 24 weeks, plasma, RBC, total blood, and extracellular fluid (ECF) volumes were determined in 7 healthy, resting foals. Evans blue dye and sodium thiocyanate were used to estimate plasma and ECF volumes, respectively. Absolute plasma volume remained stable from 2 days through 2 weeks of age, then increased progressively through 24 weeks of age. After decreasing between 2 days and 2 weeks of age, absolute RBC and total blood volumes progressively increased. Absolute ECF volume increased progressively from 2 days of age through 24 weeks o...
The major protamine from stallion sperm. Isolation and amino-acid sequence. The major stallion protamine was isolated from sperm cell nuclei by extraction with 6M guanidine/5% mercaptoethanol, alkylation with 4-vinylpyridine and subsequent reversed-phase high-performance liquid chromatography. The primary structure of stallion protamine was determined by N-terminal sequencing of the intact protein and of the fragments obtained from thermolysin cleavage of the S-pyridylethylated and from endoproteinase Lys-C cleavage of the S-aminoethylated protein. Stallion protamine consists of 49 amino-acid residues and shows 49% identity with all other sequenced mammalian type 1 pr...
A pharmacokinetic study of phenobarbital in mature horses after oral dosing. The pharmacokinetics of phenobarbital were determined in six mature horses after a single oral dose. Horses were administered a 5.5 mg/kg of body weight oral dose of phenobarbital tablets. Based on the combined evaluation of i.v. and oral results, phenobarbital displayed two-compartment pharmacokinetics in the horse with a terminal half-life of 19.0 +/- 4.4 (mean +/- SD) h. This half-life is considerably shorter than those reported for dogs and humans. The steady-state volume of distribution (Vdss/F) and the total body clearance (Clt/F) of phenobarbital were 0.753 +/- 0.115 l/kg and 27.9 +/- 9...
Unipolar thoracic electrocardiography that induces QRS complexes of relative uniformity from male horses. Electrocardiograms were obtained from 100 male crossbred horses. In addition to standard limb leads, leads were taken from 12 points on the thorax. The QRS complexes were categorized into 1 of 8 forms on the basis of configuration and amplitudes of component deflections. Relative uniformity of QRS was determined for each lead, using the percentage of horses that possess a particular configuration. All unipolar thoracic leads, except those coplanar with the frontal plane, and lead aVR had great uniformity, with greater than 80% of the horses with a QRS of similar contour.
Antigenic variation and lentivirus persistence: variations in envelope gene sequences during EIAV infection resemble changes reported for sequential isolates of HIV. The extent and nature of genomic variation among nine antigenically distinct EIAV isolates recovered during sequential clinical episodes from two experimentally infected ponies were examined by restriction fragment analysis and nucleotide sequencing. Only minor variations in restriction enzyme patterns were observed among the viral genomes. In contrast, env gene sequences of four isolates from one pony revealed numerous clustered base substitutions. Divergence in env gene nucleotide and deduced amino acid sequences between pairs of virus isolates ranged from 0.62 to 3.4% env gene mutation rate...
[Frequency of the isolation of staphylococci from domestic animals and strain identification]. Staphylococci occur in donkeys more frequently than in other animals, and only from donkeys coagulase-negative staphylococci, characteristic of humans (S. hominis, S. capitis, S. cohnii), were isolated. Least frequently staphylococcal carrier state was registered in cats; in these animals only coagulase-negative strains were found to occur. From 30 donkeys coagulase-positive staphylococci belonging to 47 S. aureus strains were isolated. These strains differed from known ecological variants in their biological properties, thus suggesting the existence of S. aureus ecovar specific for donkeys. T...
Comparison of the effects of two sets of anaesthetic agents and posture on respiratory rate, heart rate, pH, blood gas and acid-base status in the horse. Two methods of anaesthesia were evaluated in the horse for their effects on the cardiovascular and respiratory systems and on the acid-base status of the animal. In addition the effect of the position—dorsal and lateral recumbency—of the anaesthetized horse on these systems was evaluated.
The use of a passive hemolysis system to evaluate the complement activities of six mammalian species. A passive hemolysis assay system was developed which permitted comparisons of the hemolytic activities of complement (C) from six species. This system employs a single antigen and an antiserum raised in one species. Thus, variations resulting from different target antigens and those inherent in using antibodies (of different affinities and isotypes) raised in a variety of species were minimized. Of the erythrocytes (E) examined, those from horses and guinea pigs were most susceptible to lysis, and either would be suitable, as a tentative choice, for measuring C activity of a previously unstudi...
Nucleotide (cDNA) sequence encoding the horse gonadotrophin alpha-subunit. Several cDNA clones corresponding to mRNA for the alpha-subunit of the horse (Equus caballus) pituitary and placental (chorionic) gonadotrophic hormones have been isolated and sequenced. Polyadenylated mRNA was purified from horse pituitary glands (the source of FSH and LH) and horse placental tissues (the source of chorionic gonadotrophin; CG). The mRNA preparations were characterized by in-vitro translation and Northern hybridization techniques using human and ovine gonadotrophin cDNA clones as probes. Complementary DNA libraries were created from the pituitary and placental mRNAs and a huma...
Assessment of neutrophil migration, phagocytosis and bactericidal capacity in neonatal foals. Comparison of neutrophil function was made between 8 clinically normal pony foals (3 to 7 days of age), and their dams. Random migration, stimulated migration to zymosan-activated serum, bacterial phagocytosis and bactericidal capacity of neutrophils were determined in vitro. Random migration was greater (P less than 0.01) and stimulated migration was less (P less than 0.01) in foals than in their dams. Bacterial phagocytosis and bactericidal capacity of neutrophils were not different (P greater than 0.05) between foals and mares. Results of this study suggested that neonatal foals have altere...
[Isolation and purification of proteolytic enzymes on organo-silica sorbents with immobilized gramicidin S]. Biospecific sorbents for affinity chromatography of proteolytic enzymes have been synthesized by attaching cyclopeptide antibiotic gramicidin S to organo-silica supports. It is shown possible to attach gramicidin S to the organo-silica supports using glutaric aldehyde, p-benzoquinone, soluble and insoluble carbodiimides. The sorbents prepared by these methods were successfully applied for the purification of the crude pepsin from horse gastric juice and proteolytic complex produced by Acremonium chrysogenum.
Oxygen deficit-oxygen debt relationships in ponies during submaximal treadmill exercise. The O2 deficit-O2 debt relationship in ponies was examined at two levels of treadmill exercise. Five healthy ponies exercised for 8 min at two work rates (WR):(1) 50 m/min at 6% grade and (2) 70 m/min at 12% grade. The O2 deficit and O2 debt were calculated using open-circuit measurement of pulmonary gas exchange during the transition from rest to steady-state exercise and during recovery from exercise. The O2 deficit was significantly lower (P less than 0.05) than the O2 debt at each of the two work rates. The means (+/- SEM) for the deficit and the O2 debt, respectively, in liters were: (1) ...
The equine colonic mucosal granular cell: identification and X-ray microanalysis of apical granules and nuclear bodies. The granular columnar epithelial cell of the equine dorsal large colon has been studied by transmission electron microscopy and X-ray microanalysis. Particular attention was focused on nuclear bodies commonly observed as central clusters of spherical, electron-dense inclusions within the nucleus. Ultrastructural morphology as well as X-ray microanalysis spectra reveal great similarity between colonic nuclear bodies and the numerous small granules of the apical cytoplasm in these epithelial cells. X-ray spectra of these cells were distinct from those of goblet cell mucous granules and mast cell...
Size referenced electronic leukocyte counting threshold and lysed leukocyte size distribution of common domestic animal species. Using a single channel electronic cell counter and attached particle size analyzer, leukocyte size distribution histograms were determined on canine, feline, bovine, and equine blood diluted with chloride-based diluent and treated with a conventional stromatolysin. Histograms were usually unimodal, but a few were bimodal. Mean values for mean lysed leukocyte particle volume were 49.2, 51.1, 55.4, and 65.0 fl for canine, feline, equine, and bovine blood, respectively. From inspection of histograms, a lower threshold of 30 fl referenced to latex spheres was interpreted to be appropriate for coun...
Autotransfer of Day 4 embryos from oviduct to oviduct versus oviduct to uterus in the mare. Embryo autotransfer is defined as the collection of an embryo from and the transfer of this embryo into the same animal. The objectives of this study were to: 1) test the hypothesis that oviduct transport of the equine embryo from the oviduct into the uterus is not dependent on a unilateral embryo-corpus luteum interaction, 2) develop an embryo autotransfer technique for the mare and 3) compare the success rates of Day 4 embryos surgically autotransferred from the oviduct ipsilateral to ovulation to either the oviduct (n=10 mares) or the uterine horn (n=10 mares) contralateral to ovulation. Se...
Management of twin conceptuses by manual embryonic reduction: comparison of two techniques and three hormone treatments. One hundred mares carrying twin conceptuses between gestation days (GD) 12 and 30 were assigned to 4 groups. Group-1 mares (n = 20) were given a placebo (sterile saline solution, IV, and sesame oil, IM). Group-2 mares (n = 32) were given a single dose of progesterone (625 mg, IM) in sesame oil. Group-3 mares (n = 28) were given multiple progesterone treatments (625 mg, IM) at 6-day intervals until GD 42. Group-4 mares (n = 20) were given a single treatment of flunixin meglumine (500 mg, IV) and progesterone (625 mg, IM). Each group was further assigned to equal subgroups A and B according to t...
Effects of physiologic and pharmacologic agents on serum prolactin concentrations in the nonpregnant mare. Four studies were conducted to evaluate the effects of several physiologic and pharmacologic agents on serum prolactin concentrations in the nonpregnant mare. An increase in prolactin measured in response to administration of thyrotropin-releasing hormone (TRH; 50 micrograms, iv) was found not to vary (P = .20) in mares in estrus compared with mares in diestrus (5 to 10 d post-ovulation). Administration in the dopamine receptor blocker, metoclopramide (25 or 100 mg, im), rapidly increased serum prolactin, and the response was dependent on dose administered (total prolactin measured for 420 min...
Measurements of muscular microcirculation by laser Doppler flowmetry in isoflurane and halothane anaesthetised horses. The cardiovascular function of horses was less depressed during anaesthesia with isoflurane than during anaesthesia with halothane. Muscular microcirculation measured by laser Doppler flowmetry was significantly greater in horses anaesthetised with isoflurane.
