Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
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.
Crystallographic studies of a calcium binding lysozyme from equine milk at 2.5 A resolution. The crystal structure of a calcium binding equine lysozyme has been determined at 2.5 A resolution by means of molecular replacement. The energy minimized equine lysozyme as the starting model, was refined with the molecular dynamics program, X-PLOR, and the R factor of the current model was found to be 24% without any water molecules. The conformation of the calcium binding loop is similar to that of alpha-lactalbumin. The profiles of backbone atomic displacements throughout the lysozyme and alpha-lactalbumin superfamilies are comparable as well as their homologous tertiary structures.
Species restrictions demonstrated by the stimulation of equine cells with recombinant human interleukin-1. Equine thymocytes, which respond to equine monocyte supernatants, do not respond to stimulation with recombinant human interleukin-1 alpha and beta, and equine synovial fibroblasts show a limited response in the form of prostaglandin E2 production without any evidence of neutral metalloproteinase production. Human interleukin-1 beta was about three to ten times as active on equine synovial cells as human interleukin-1 alpha in terms of prostaglandin E2 production. This preliminary evidence would suggest that there are qualitative and quantitative differences in the way recombinant human interl...
Susceptibility of corneas from various animal species to in vitro binding and invasion by Acanthamoeba castellanii [corrected]. A crucial requirement for establishing corneal infection by the extracellular protozoal parasite, Acanthamoeba, is the ability of the parasite to bind to the corneal surface. In a series of in vitro studies, we examined the ability of Acanthamoeba castellanii [corrected] to adhere, invade, and damage normal, intact corneas of 11 mammalian and one avian species. A. castellanii [corrected] (80-90% trophozoites and 10-20% cysts) were incubated with corneas for 24 hours in vitro and examined by scanning electron microscopy (SEM). Results of several independent SEM experiments revealed that parasit...
Free fatty acids in exercising Arabian horses fed two common diets. Four Arabian geldings were used in a randomized, repeated measure design to study the effect of two different diets on plasma free fatty acids at rest and during exercise. On each of four sampling days, two horses were fed one of two isoenergetic diets, either 100% corn or 100% alfalfa, at 22% of their estimated daily energy requirement. Two hours after the consumption of the diet, each horse participated in a submaximal standard exercise test consisting of three consecutive 10-min runs of increasing intensity at heart rates of 132, 140 and 147 beats/min, respectively. There were no significan...
An immunoperoxidase method applied to the diagnosis of equine herpesvirus abortion, using conventional and rapid microwave techniques. An indirect immunoperoxidase (IMP) technique was applied to cryostat and paraffin sections of liver from ten aborted equine foetuses. Equid herpesvirus type 1 (EHV-1) had been isolated from seven of them and EHV-4 from one: the remaining two were virologically negative and were not used as controls. In the eight virus-infected cases the immunostaining revealed foci of cells exhibiting a distinct brown cytoplasmic and inclusion body pigmentation. No specific signal was present in the non-infected controls. The method also was adapted for incubation in a microwave oven, which allowed the total l...
Putative fragile sites in the horse karyotype. After fluorouracil/5-bromodeoxyuridine synchronization and subsequent FPG-staining, the karyotype of 15 phenotypically normal horses displayed several breaks and gaps. Twelve bands 1q24, 4p12, 8q23, 11p12, 16q21, 17q21, 23q31, 23q32, Xp21, Xq22, Xq25 and Xq27 showed relatively frequent fragility. After thymidine/cytidine synchronization and subsequent GWL-banding the same horses display karyotypes without any fragility. Hence it is suggested that the above listed bands harbour folate and/or 5-bromodeoxyuridine sensitive fragile sites.
A new genetic variant Z2 in the Pi system of horses. A new genetic variant in the horse Pi system, designated Z2, was reported in Polish Arabs by using two-dimensional agarose polyacrylamide gel electrophoresis. The frequencies of Pi alleles F, G, L, L2, N, S, U, W, Z and Z2 were found to be 0.036, 0.005, 0.171, 0.013, 0.008, 0.237, 0.416, 0.003, 0.107 and 0.004 respectively.
An evaluation of the effect of reagent modification on routine laboratory coagulation tests. The purpose of this study was to evaluate the effect of modifying commercial reagents for the laboratory evaluation of several haemostatic parameters in normal, non-pregnant mares. The routine coagulation screening assays, namely, the activated partial thromboplastin time (APTT) and the one-stage prothrombin time (PT), and the specific coagulation assays for the determination of the biological activity of Factors VII, VIII:C and IX, are discussed.
New A system allele of red cell alloantigens in Paso Fino horses. Family data from Paso Fino horses support the existence of a new allele (Aabdf) in the A system of red cell alloantigens. Considering breeds throughout the world, the A system now consists of 13 alleles defined by reagents which serologically detect seven factors.
Interference of maternal antibodies with the immune response of foals after vaccination against equine influenza. The purpose of the study was twofold. First, using two groups of 22 foals each, we investigated the extent to which maternal antibodies interfere with the humoral response against equine influenza. The foals were born to mares that had been vaccinated twice yearly against influenza since 1982. Foals of group I were vaccinated three times at early ages (12, 16, and 32 weeks of age), and foals of group II were likewise vaccinated but a later ages (24, 28, and 44 weeks of age). After the first and second vaccinations, neither group showed an increase in antibodies that inhibit haemagglutination. ...
Identification of equine chromosomes in horse x mouse somatic cell hybrids. Giemsa-11 (G-11) staining and in situ hybridization were used to identify the equine chromosome complement of horse x mouse somatic cell hybrids. The presence of horse chromosomes in somatic cell hybrids was determined by differential G-11 staining. The slides were then destained and hybridized with biotinylated total horse (Equus caballus) genomic DNA without suppression. Fluorescence detection permitted rapid confirmation of horse chromosomal DNA in the hybrid cells.
Stabilization of the structure of horse plasma vitamin D binding protein by disulfide bonds. Vitamin D binding protein (DBP) was isolated from horse plasma in a four-step procedure that involved Affi-Gel Blue affinity chromatography, gel filtration, hydroxylapatite chromatography, and anion exchange high-pressure liquid chromatography. The yield of DBP from 80 mL of plasma was 6-7 mg. Horse plasma DBP closely resembles other plasma DBPs, being a tryptophan-free protein of Mr 53,000. It is able to bind to and block the polymerization of monomeric actin. The secondary structure of DBP was calculated from circular dichroism measurements to be 39% alpha-helix, 42% beta-sheet, and 19% rand...
[Physical performance–a comparison between horses and men]. During heavy exercise horses can increase oxygen uptake compared to resting conditions considerably more than man. Processes involved like respiration, heart size, cardiac output, oxygen transport capacity of the blood and oxygen release in the capillaries are discussed. Besides these advantages in the aerobic metabolism conditions for the anaerobic metabolism are also more advantageous in horses than in man. The portion of fast contracting muscle fibers with little fatigue-resistance and also some of the enzymes required for the anaerobic metabolism are higher in horses.
Localization of the calcium release channel gene in cattle and horse by in situ hybridization: evidence of a conserved synteny with glucose phosphate isomerase. In situ hybridization techniques were used to localize regionally the calcium release channel (CRC) gene on cattle and horse chromosomes, using a porcine CRC cDNA probe. In cattle, the hybridization signal peaked on the 18q23-q26 bands and in horse on the 10pter region. Previous studies have shown that the glucose phosphate isomerase (GPI) gene localizes at the same site in both species, indicating that the two loci are syntenic. As CRC and GPI are syntenic in human, pig and mouse, the present results in cattle and horse represent another example of synteny conservation in the evolution of mam...
Pinealitis coincident with recurrent uveitis: immunohistochemical studies. Although experimental models of autoimmune uveitis predict pinealitis coincident with uveitis, there is no direct evidence of pineal pathology accompanying a human uveitis. Horses with naturally occurring uveitis are a potential source of eye and pineal tissues that are not available from human patients with active uveitis. We have observed pinealitis in a mare with equine recurrent uveitis. By immunohistochemistry we demonstrated immunoglobulin and MHC Class II antigen on infiltrating and resident cells of eye and pineal gland. These results support the relevance of the animal models and sugg...
DNA fingerprinting in horses using a simple (TG)n probe and its application to population comparisons. A synthetic polynucleotide (TG)n was hybridized to equine DNA digested with HinfI and hypervariable hybridization patterns were obtained. Mendelian inheritance of these DNA fingerprinting patterns was confirmed by pedigree analysis. Estimates of the probabilities of identical band patterns in unrelated individuals of different breeds (Swedish Trotters, North Swedish Trotters, Thoroughbreds and Arabians) were in the range 1 x 10(-4) - 7 x 10(-6). The variability derived with the (TG)n probe in horses was higher than what we obtained with several other commonly used probes for DNA fingerprinting...
An inhibitor of tumor cell growth from normal horse serum. During our studies of cytostatic cytokines in the mixed leukocyte culture, we found that horse serum in the medium control contained a tumor cell growth-inhibitory factor. The fraction isolated by molecular sieving and ion exchange chromatography inhibited the growth and DNA synthesis of the primary culture and passaged cell line of the canine transmissible venereal sarcoma, murine T (L5178Y) and B (P3-X63-Ag8.653) lymphoid tumor cells, murine mammary tumor cells (RIII), bovine lymphoid tumor cells (BL3), and the nontransformed cell line of baby hamster kidney cells. Nontransformed cell lines ...
Domestic animal models of severe combined immunodeficiency: canine X-linked severe combined immunodeficiency and severe combined immunodeficiency in horses. This review describes the clinical, immunologic and pathologic features of two naturally-occurring models of severe combined immunodeficiency (SCID) in domestic animals that represent different forms of human SCID. Canine X-linked SCID (XSCID) has an X-linked recessive mode of inheritance and, as such, represents a model for the most common form of human SCID in the United States. Affected dogs have normal percentages of circulating B cells and low to normal percentages of phenotypically mature, but nonfunctional T cells. Severe combined immunodeficiency in the horse is an autosomal recessive ...
A comparison of end-tidal halothane concentrations measured at proximal and distal ends of the endotracheal tube in the horse. Measurements (n = 126) of end-tidal halothane concentrations were taken from 21 horses anesthetized for routine and emergency surgery. One hundred five paired values allowed comparison of gas samples taken near the oral end of the endotracheal tube (Y1) to samples obtained at the cuffed end of the endotracheal tube (Y2). Twenty-one paired readings were assessed to compare samples taken 25 cm beyond the cuffed end of the tube (Y3) to samples from Y1. Measurements were made at all locations at 15-minute intervals starting 30 minutes after beginning halothane. All measurements were made in tripli...
One-dimensional isoelectric focusing and immunoblotting of equine major histocompatibility complex class I antigens. The cells of 60 randomly selected Hannoveranian warm-blooded horses were subjected to one-dimensional isoelectric focusing and immunoblotting with a cross-reacting monoclonal antibody (Bo 1) recognizing bovine class I antigens. The banding patterns were correlated with the serologically defined specificities of the ELA-A locus. ELA-A2 was correlated with four bands, while ELA-A5, ELA-W18, ELA-A6, ELA-A14 and ELA-A9 were correlated with a single band each. The complexity of the pattern and additional polymorphic bands which could not be correlated to any of the known ELA specificities may indic...
Effects of treadmill exercise on cortical bone in the third metacarpus of young horses. The effects of exercise and relative inactivity on cortical bone were compared in young horses. Two groups were used; one was given a 14-week programme of exercise (n = 6) and the other kept as unexercised controls (n = 6). The first nine weeks of exercise involved trotting and cantering (2 to 4 km d-1 at speeds up to 12 m s-1) on a treadmill set at an incline of 3 degrees. Over the next five weeks the horses were trained at near maximal speeds (that is, up to 14.5 m s-1) with no incline of the treadmill. At the end of the programme marked differences in cortical porosity and distribution of s...
In vivo measurement of bone quality in the horse: estimates of precision for ultrasound velocity measurement and single photon absorptiometry. The in vivo precision of ultrasound velocity measurement and single photon absorptiometry for the assessment of equine bone quality is discussed. In vivo precisions for ultrasound velocity measurements were less than 0.5 per cent, whereas cortical cross-sectional area, compact bone density and modulus of elasticity were around 1 per cent, and bone mineral content and density were just over 2 per cent. Except for ultrasound velocity, substantial improvements could be achieved by taking the mean of five readings for each measurement. The long-term precision of the techniques was also high, with ...
Ketamine, Telazol, xylazine and detomidine. A comparative anesthetic drug combinations study in ponies. This study was designed to assess the effects of 5 anesthetic drug combinations in ponies: (1) ketamine 2.75 mg/kg, xylazine 1.0 mg/kg (KX), (2) Telazol 1.65 mg/kg, xylazine 1.0 mg/kg (TX), (3) Telazol 2 mg/kg, detomidine 20 micrograms/kg (TD-20), (4) Telazol 2 mg/kg, detomidine 40 micrograms/kg (TD-40), (5) Telazol 3 mg/kg, detomidine 60 micrograms/kg (TD-60). All drugs were given iv with xylazine or detomidine preceding ketamine or Telazol by 5 min. Heart rate was decreased significantly from 5 min to arousal after TD-20 but only at 60 and 90 min after TD-40 and TD-60 respectively. Respirato...
Evolutionary pattern of the H 3 haemagglutinin of equine influenza viruses: multiple evolutionary lineages and frozen replication. The nucleotide and deduced amino acid sequences of the haemagglutinin genes coding for the HA 1 domain of H3N8 equine influenza viruses isolated over wide regions of the world were analyzed in detail to determine their evolutionary relationships. We have constructed a phylogenetic model tree by the neighbour-joining method using nucleotide sequences of 15 haemagglutinin genes, including those of five viruses determined in the present study. This gene tree revealed the existence of two major evolutionary pathways during a twenty five-year period between 1963 to 1988, and each pathway appeared t...
Capillary supply and fibre area in locomotor muscles of horse and steer–a comparison between histochemistry and electron microscopy. In order to investigate possible differences in variables defining capillary supply of skeletal muscle derived from two methods, the electron-microscopical and the amylase-PAS histochemical methods were applied in a study of horse and steer muscles. Samples from several locomoter muscles were taken at slaughter from one horse and one steer, divided into two and prepared separately for the two techniques. It was found that there was no difference between the two methods in the values for the capillary-to-fibre ratio. Values for mean fibre area, on the other hand, were significantly higher in th...
Bee venom melittin is a potent toxin for reducing the threshold for calcium-induced calcium release in human and equine skeletal muscle. The modulation of Ca2+ release by synthetic bee venom melittin was examined in equine and human terminal cisternae-containing fractions. Melittin (0.1 microM) decreased the threshold of Ca(2+)-induced Ca2+ release by 20% in equine muscle and by 36% in human muscle. If terminal cisternae fractions were first preloaded with Ca2+ to greater than about 75% of the threshold of Ca(2+)-induced Ca2+ release and then melittin added, an immediate and sustained release of Ca2+ occurred in preparations from both species. Addition of melittin after a Ca2+ preload of < 50% of the threshold of Ca(2+)-induced...
Evaluation of the haemostatic profile in the pre- and post parturient mare, with particular focus on the perinatal period. Various haemostatic analytes were systematically evaluated for four months pre-partum and five months post partum in 14 healthy mares. The plasma fibrinogen concentration and both Factor VIII:C and von Willebrand factor activity showed gradual increases from mid-gestation and reached maximal, or near maximal activity at parturition. These increases were paralleled by an increase in plasma fibronectin concentration, the appearance of fibrinogen degradation products, and a modest rise in antithrombin III concentration. In contrast, the activity of Factor VII and Factor IX, and the one-stage prot...
