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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.
Development of diurnal rhythm in some metabolic parameters in foals. 1. The development of diurnal rhythm activity of FDPA, AspAT and A1AT and in levels of cortisol, T3 and T4 was observed in the blood serum of six foals. 2. The studies began when a foal was 7 days old and were repeated every month until foals reached 1 year of age. Blood samples were taken every 4 hr for one day each month. 3. As a control group four barren mares were used, kept and examined in the same conditions. 4. In mature mares, diurnal rhythms in activity of A1AT (acrophase at 2200 hr), AspAt (2400 hr) and cortisol (0630 hr) but in T3 only in summer months (acrophase at 0100 hr) were ob...
Investigations of the horse conceptus via magnetic resonance imaging (MRI) and nitroxide spin labels as contrast agents. Results are presented which illustrate the usefulness of Magnetic Resonance Imaging as applied to the study of living embryos. Nitroxide spin labels were employed as contrast agents to study the structure and properties of the embryos. These spin labels offer the additional advantage that they may potentially be bound to biologically important molecules thereby imparting the ability to produce contrast in the MR images to these new molecules. The horse conceptus was chosen over other embryos due to its large size. Whereas the embryos of cattle and swine are sub-millimetre in size, the horse co...
Multifocal innervation and muscle length. A morphological study on the role of myo-myonal junctions, fiber branching and multiple innervation in muscles of different size and shape. The dependence of the inner organisation and innervation of a skeletal muscle on its size was studied at the level of single muscle fiber architecture and motor endplate topography in muscles of different size, all of them lacking a tendinous scaffolding. The muscles evaluated in this study were: Mm. sternomastoideus, gracilis and latissimus dorsi of the rat and the M. sternocephalicus of the horse. In these muscles a subdivision into two or more 'innervation-compartments' becomes obvious in fascicles reaching a certain length. This provides the possibility of an almost synchronous activation ...
Structure and expression of the equine infectious anemia virus transcriptional trans-activator (tat). Equine infectious anemia virus (EIAV) encodes a tat gene which is closely related to the trans-activators encoded by the human and simian immunodeficiency viruses. Nucleotide sequence analysis of EIAV cDNA clones revealed that the tat message is composed of three exons; the first two encode tat and the third may encode rev.. Interestingly, EIAV tat translation is initiated at a non-AUG codon in the first exon of the message, perhaps allowing an additional level of gene regulation. The deduced amino acid sequence of EIAV tat, combined with functional analyses of tat cDNAs in transfected cells, ...
The immunocytochemical distribution of seven peptides in the spinal cord and dorsal root ganglia of horse and pig. The distribution of calcitonin gene-related peptide (CGRP), enkephalin, galanin, neuropeptide Y (NPY), somatostatin, tachykinins and vasoactive intestinal polypeptide (VIP) was compared in cervical, thoracic, lumbar and sacral segmental levels of spinal cord and dorsal root ganglia of horse and pig. In both species, immunoreactivity for the peptides under study was observed at all segmental levels of the spinal cord. Peptide-immunoreactive fibres were generally concentrated in laminae I-III, the region around the central canal, and in the autonomic nuclei. A general increase in the number of i...
Primary structure of horse serotransferrin glycans. Demonstration that heterogeneity is related to the number of glycans and to the presence of N-acetylneuraminic acid and N-acetyl-4-O-acetylneuraminic acid. Three serotransferrin variants Tf 2a, Tf 4b and Tf 5b were isolated in an homogeneous form from a preparation of homozygous horse serotransferrin Tf 0. On the basis of the results concerning molecular mass determination and the carbohydrate analysis, it is concluded that the serotransferrin variant Tf 2a contains only one glycan while variants Tf 4b and Tf 5b contain two glycans. The structure of all of the glycans has been established by combining methylation analysis, mass spectrometry and 400-MHz 1H-NMR spectroscopy. From the obtained results, it appears that the two glycans of Tf 5b varian...
Comparison of bacteriologic culture of blood and necropsy specimens for determining the cause of foal septicemia: 47 cases (1978-1987). Diagnosis of bacterial septicemia was confirmed by results of bacteriologic culture of antemortem blood samples and/or necropsy specimens obtained from 47 foals up to 8 days old. Gram-negative bacteria were isolated from all 47 foals, and mixed infections with more than one organism were involved in 26 (55%). Escherichia coli, Actinobacillus spp, and Klebsiella pneumoniae were the most frequent isolates, infecting 55, 34, and 23% of foals, respectively. Gram-positive bacteria and anaerobic bacteria were isolated only from foals with mixed infections with gram-negative organisms. Clostridium pe...
Transbilayer movement of phosphatidylserine in nonhuman erythrocytes: evidence that the aminophospholipid transporter is a ubiquitous membrane protein. A 31-32-kDa integral membrane protein has been previously identified in erythrocytes as the protein most likely to be responsible for the transbilayer movement of phosphatidylserine (PS) [Connor & Schroit (1988) Biochemistry 27, 848-851]. Using similar techniques, we have identified analogous proteins of identical molecular weights in bovine, equine, ovine, porcine, canine, caprine, and rhesus red blood cells. Similar to human red blood cells, all of the mammalian cells were able to specifically transport an exogenously supplied fluorescent PS analogue from their outer-to-inner membrane le...
Serum uric acid concentrations in horses heterozygous for combined immunodeficiency. Serum uric acid concentrations were determined in horses known to be carriers of combined immunodeficiency gene(s) and in presumed noncarrier horses. Uric acid concentrations were significantly higher (P less than 0.005) in carrier horses than in presumed noncarrier horses. However, there was some overlap in serum uric acid concentrations between carrier and presumed noncarrier horses.
[Electron microscopic detection rate of enteral viruses in diarrhea of dogs, cats, calves, swine and foals in the year 1988–electron microscopic study results]. During 1988 fecal and gut samples of 641 dogs, 198 cats, 576 calves, 108 piglets and 64 foals with diarrhoea were investigated for virus infections by electron microscopy. In samples of dogs and cats parvovirus was detected at a proportion of 21.9% and 16.7%, respectively; rotavirus alone or together with coronavirus was found only in 0.3-1.5% of the specimens. In samples of calves rotavirus, as well as coronavirus dominated with a detection rate amounting to 17.4% and 26.6% respectively (including 4.5% of mixed infections); parvovirus was present in a ratio of 0.5%. Specimens of piglets mainl...
Tracheal mucus transport rate in healthy horses. Tracheal mucus transport rates were measured over a 10-minute period in 20 healthy horses twice in 24 hours. The mean rate was 1.93 +/- 0.55 cm/min on day 1 and 1.99 +/- 0.49 cm/min 24 hours later. The mean difference between day 1 and day 2 (0.06 +/- 0.42 cm/min) was not significant (P = 0.55). The range on day 1 was 1.12 to 2.9 cm/min and 1.11 to 2.89 cm/min on day 2.
Cardiovascular effects of detomidine, a new alpha 2-adrenoceptor agonist, in the conscious pony. The cardiovascular effects of detomidine and xylazine were compared in six chronically instrumented, conscious ponies. Ponies were instrumented with a micromanometer in the left ventricular chamber, a Doppler flow probe on a coronary artery and sonomicrometer crystals in the left ventricular free wall. Heart rate, ventricular systolic pressure, stroke work, dP/dtmax, minute work and coronary blood flow were measured for 4 h following intravenous injection of detomidine at several doses or xylazine at 1.1 mg/kg. Both drugs caused a profound hypertensive response at 15 s post-injection. The magn...
Heart weight and running ability. The weight of the heart as determined by dissection techniques was compared with liveweight and total muscle weight in different types of horses and dogs as adults and during growth. With increasing body size both within and between species, heart weight forms a lesser proportion of liveweight and of total muscle weight. Heart weight forms a greater proportion of liveweight in Thoroughbreds and Greyhounds (breeds noted for high speed running) than in other less fleet members of their species and Greyhounds have greater heart weights relative to total muscle weight than other dogs.
[Detection of streptococci from various serological groups in animals]. During the period from 1985 to 1988 we determined 228 strains of streptococci isolated from samples of various sorts of biomaterials, mainly animals. From this set of streptococci we classified 207 strains into serological groups according to the Lancefield classification and about 30% strains into species by means of serological and biochemical methods. Most of the strains were allocated to group C (37.28%) and group Q (17.39%). 89 streptococci strains originated from pigs, 40 strains from horses, 13 from cattle, 12 from dogs, 9 from poultry and 8 from coypu. The other streptococci strains or...
Cross-neutralizing and subclass characteristics of antibody from horses with equine infectious anemia virus. Antibody responses in horses with equine infectious anemia virus (EIAV) were examined to determine their cross-neutralizing capacity. Antibodies induced by infection with any of six biologically cloned variants of EIAV cross-neutralized multiple variants from the group. Anti-EIAV antibody was found in both the IgG and IgG(T) subclasses in plasmas with virus-neutralizing activity and the majority of antiviral antibody was of the IgG(T) subclass. Depletion of IgG(T) did not increase the neutralization indexes of either neutralizing or non-neutralizing plasma samples.
Influence of technical parameters on the in vitro motility of equine neutrophils in the presence of streptococcal culture supernatant. To identify the influence of technical factors on the in vitro motility of equine neutrophils towards streptococcus culture supernatant in an under-agarose assay, we studied the changes in eight cell migration parameters. The distances the phagocytes travelled by directed, random and spontaneous migration increased with incubation time, cell concentration and the gelatin and serum contents of the migration plates. The contribution of chemotaxis to the phagocyte migrations, however, decreased simultaneously. The directed and random, though not the spontaneous, migrations of the phagocytes incre...
A hemolytic assay for the measurement of equine complement. A hemolytic assay was developed for the measurement of functional equine complement activity. The assay utilizes antibody sensitized chicken erythrocytes as the target cell and was specific for classical pathway (antibody dependent) complement activity. The assay was found to be reproducible and more sensitive than previous reports using other species of target cells. Total serum complement (CH50) values were determined for five mares and their foals and followed over a period of 3 months.
Accuracy of prediction of the liveweight of horses from body measurements. Fifty-three horses, all but two of them over two years of age and varying in type, sex and liveweight (230 to 707 kg) were weighed and seven different body measurements were recorded in duplicate by a single operator. The best overall prediction of liveweight using an equation with two variables was found to be: liveweight (kg) = (umbilical girth [cm])1.78 X (length of body from tuber ischii to elbow [cm]0.97/3011). This equation had an adjusted R2 value of 94.9 per cent and was derived from the pooled data, because differences of sex, type and weight did not significantly affect the relations...
Influence of clenbuterol on mucociliary transport in healthy horses and horses with chronic obstructive pulmonary disease. The mucociliary tracheal transport rate and clearance index were measured in 16 healthy horses and 16 horses suffering from chronic obstructive pulmonary disease. A marker, Indian ink in syrup, was placed in the mucus layer of the interior wall of the trachea, just in front of the carina, and its displacement was measured after 30 and 60 minutes. The same procedure was repeated 30 minutes after the intravenous administration of 0.8 microgram clenbuterol/kg bodyweight. In the diseased horses the mucociliary transport rate was significantly lower than in the healthy horses. After clenbuterol adm...
Cervical hyperplasia with prolapse in a mare. Cervical hyperplasia with prolapse through the vulvar lips was documented in a mare. Postmortem examination indicated that the mass originated from the cervical wall. The surface of the prolapsed mass had histologic features of normal cervix. Cervical hyperplasia can be considered in a list of differential diagnoses in cases of prolapse of the internal genitalia in mares.
Methods of stimulating acupuncture points for treatment of chronic back pain in horses. Horses with chronic back pain of 2 to 108 months' duration were treated using acupuncture (n = 15), laser acupuncture (n = 15), or injection acupuncture (n = 15). Horses were treated once a week for 8 treatments (mean) with needle acupuncture, 11 treatments with laser acupuncture, or 9 treatments with injection acupuncture. After treatment, 37 horses had alleviation of clinical signs of pain and could train and compete: 13 horses treated with needle acupuncture; 11 horses treated with laser acupuncture; and 13 horses treated with injection acupuncture. Seemingly, the 3 types of acupuncture wer...
Navicular bone disease: a comparative histomorphometric study. Twelve horses suffering from navicular bone disease were examined in a prospective, controlled histomorphometric study for six months. The objective was to compare the histology of navicular bones from untreated animals to those treated with the egg-bar shoeing technique. These data were compared to similar sections from three normal animals. The current investigation provided quantitative support to previous findings concerning clinical improvement. Detailed histology, changes in bone morphometry and pathophysiological reactions are discussed.
Histochemical and molecular determination of fiber types in chemically skinned single equine skeletal muscle fibers. Until now, there has been no reliable method for histochemical determination of fiber types of single skinned muscle fibers. The major problem arises from the fact that most histochemical techniques use cross-sections of a large group of fibers and compare a given fiber with those surrounding it. This is not possible with a single skinned fiber which has been separated from a bundle to be used for mechanical analysis. A further problem is that the skinning procedure itself may alter the staining pattern. We have developed a procedure by which multiple cross-sections of single skinned fibers ca...
Changes in circulating equine erythrocytes induced by brief, high-speed exercise. Five horses were exercised at 10m/sec at a 3 degree incline for 2 mins. Packed cell volume, erythrocyte count, haemoglobin concentration, mean corpuscular volume, plasma protein, total white cell count and lymphocytes increased significantly in blood samples taken after exercise, compared with those taken before exercise; but mean corpuscular haemoglobin and mean corpuscular haemoglobin concentration decreased. Erythrocytes were more resistant to osmotic stress after exercise, but their shape and degree of deformity were unaffected by exercise.
Development of the navicular bone in foetal and young horses, including the arterial supply. A macroscopic, arteriographic and histological study of the development and the arterial anatomy of the navicular bone of 33 foetuses and 55 young horses is described. After 125 days of gestation the blood supply consists of two routes: one situated in the superficial layer of the fibrocartilage and the other similar to the blood supply of the navicular bone of the normal mature horse. After 270 days gestation, the blood vessels in the fibrocartilage gradually regressed and retracted until they have disappeared at six months after birth. At two months after birth the first macroscopic thinning...
The effect of artificial occlusion of the Ramus navicularis and its branching arteries on the navicular bone in horses: an experimental study. The clinical, radiographic, arteriographic, scintigraphic and histological effects of experimental occlusion of the Ramus navicularis (R. Navicularis) and its branching arteries are evaluated. Occlusion of the R. navicularis and its branching arteries creates changes, arteriographically and histologically, which resemble those of navicular disease. The increased bone remodelling, the shift in arterial pattern, the formation of collaterals and the increased connective tissue in the synovial membrane and nutrient foramina, as a reaction to the reduction of the distal arterial supply of the navic...
Comparison of bacteria isolated from specimens obtained by use of endoscopic guarded tracheal swabbing and percutaneous tracheal aspiration in horses. Results of bacteriologic culture of specimens obtained from 14 horses with pneumonia and from 15 horses that were clinically healthy (nonpneumonia group) were compared. Specimens were obtained by use of an endoscopic guarded tracheal swabbing method and percutaneous tracheal aspiration. The percentage of agreement between the 2 tracheal specimens for the horses of the pneumonia group was 79% for aerobic isolates and 100% for anaerobic isolates. The percentage of agreement between results of the 2 tracheal specimens for horses of the nonpneumonia group was 80% for aerobic organisms and 93% for ...
Androgen and 19-norandrogen aromatization by equine and human placental microsomes. The ability of equine and human placental microsomes to aromatize testosterone and 19-nortestosterone was studied. When 3 microM [1 beta,2 beta-3H]testosterone was used as substrate, the specific activity of equine placental microsomal aromatase was 2.5 times higher than that of the human microsomal enzyme. Although 19-nortestosterone was aromatized 67 times more rapidly by equine than by human aromatase, we found that equine aromatase exhibited a markedly weaker affinity for this substrate than did the human enzyme. Competitive inhibition of testosterone aromatization by 19-nortestosterone oc...
