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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.
Significance of affinity and cooperativity in oxygen binding to hemoglobin of horse fetal and maternal blood. The physiological significance of the position and shape of the oxygen equilibrium curve (OEC) of horse hemoglobin (Hb) is considered from the viewpoint of oxygen (O2) transport efficiency and the effectiveness of the Bohr effect. In horse fetal and maternal bloods, their physiological O2 affinities are nearly optimized with respect to the effectiveness of the Bohr shift occurring at the O2 release site, when it is measured by the change in O2 saturation per unit change in P50. With relatively low cooperativity (n=2.69) of horse Hb under physiological conditions, the effectiveness of the Bohr ...
In vitro comparison of equine cancellous bone graft donor sites and tibial periosteum as sources of viable osteoprogenitors. To compare the osteogenic potential of cancellous bone of conventional graft sites with that of one nonconventional site (fourth coccygeal vertebra) and to investigate the tibial periosteum as a donor site with respect to osteogenic potential. Methods: In vitro osteogenic cell culture system. Methods: Eight adult horses. Methods: Cancellous bone or tibial periosteum was aseptically collected and cut into bone chips or periosteal strips of 1 to 2 mm(3) for primary explant cultures. After 2 weeks, primary tissue cultures that yielded a population of osteogenic cells were counted and subcultured ...
Characterization of the horse (Equus caballus) IGHA gene. Nucleotide sequences of the immunoglobulin constant heavy chain genes of the horse have been described for IGHM, IGHG and IGHE genes, but not for IGHA. Here, we provide the nucleotide sequence of the genomic IGHA gene of the horse ( Equus caballus), including its secretion region and the transmembrane exon. The equine IGHA gene shows the typical structure of a mammalian IGHA gene, with only three exons, separated by two introns of similar size. The hinge exon is located at the 5' end of the CH2 exon and encodes a hinge region of 11 amino acids, which contains five proline residues. The coding ...
M-mode echocardiographic ratio indices in normal dogs, cats, and horses: a novel quantitative method. A novel method for quantitative echocardiographic interpretations is introduced based on the calculation of ratio indices in which each raw M-mode measurement is divided by the aortic root dimension (Ao). "Aorta-based" indices were calculated with the animal's measured aortic root dimension (Ao(m)) as the length standard. Conversely, "weight-based" indices employed an idealized estimate of aortic dimension (Ao(w)) with a weighted least squares linear regression against the cube root of body weight (Ao(w) = kW(1/3)). Use of these indices circumvented undesirable statistical characteristics inhe...
Equine cyathostome populations: accuracy of species composition estimations. Historically, surveys of equine parasites either are not quantitative in regard to prevalence and intensities of cyathostome species, or if quantitative, are estimates based on the identification of a very small sample of the population. Commonly 100-200 worms are identified. In the current study cyathostomes from 10 ponies were counted and identified to species in subsets of approximately 200 worms each from 5% aliquots of the large intestine contents until all worms in the aliquot were examined. A mean of 10.9+/-4.3 species were identified by examining 200 cyathostomes from each animal. This...
Characterisation of movement pattern and velocities of stallion spermatozoa depending on donor, season and cryopreservation. The aim of the study was to compare different types of movement pattern and velocities of stallion spermatozoa depending on cryopreservation during breeding and non-breeding season. Ejaculates were collected from four stallions during May (n = 24) and December (n = 24). Parameters of sperm movement were evaluated by computer-aided sperm analysis (CASA) system, and included percentages of motile spermatozoa, different patterns of motility, the velocity, linearity (LIN), amplitude of lateral head displacement (ALH) and beat-cross frequency (BCF). In winter the average percentages of motility wer...
Comparison of the caudal lung borders determined by percussion and ultrasonography in horses with recurrent airway obstruction. The aim of the study was to evaluate the diagnostic value of thoracic percussion and ultrasonography with the help of distance measurements and statistical methods in the determination of the caudal lung border in horses with recurrent airway obstruction (RAO). Examinations were performed on 11 healthy, warm-blooded horses of different breeds, age and grade of disease. First, the caudal lung border was determined by the traditional indirect percussion method in the 10th, 12th, 14th and 16th intercostal spaces at the end of inspiration and expiration on both sides of the thorax. To apply standa...
Differences in polymorphonucleocyte function and local inflammatory response between horses and ponies. Wound healing proceeds faster in ponies than in horses and complications during healing, such as wound infection, occur less frequently in ponies. Earlier studies suggested that this difference might be related to differences in the initial post traumatic inflammatory response. Objective: That polymorphonuclear leucocyte (PMN) function and profiles of humoral factors in local inflammatory processes are different in horses and ponies. Methods: PMNs were isolated from venous blood of horses and ponies. Chemotaxis and reactive oxygen species (ROS) production was determined. Tissue cages were impl...
Effects of oat processing on the glycaemic and insulin responses in horses. This study was conducted to evaluate the effects of different oat processing techniques on the plasma glucose and insulin response in horses. In a cross-over design, six horses (ages 4-15 years, mean body weight+/-SD: 450+/-37 kg) were fed in random order: untreated oats, finely ground, steam-flaked and popped oats. The total oat intake varied between 1.05-1.5 kg/day, and the amount of diet was adjusted to a starch content of 630 g starch per day and horse (1.2-1.5 g starch/kg BW/day). During the stabilization period of 10 days, horses additionally received 6 kg grass hay. Following this adapt...
Studies on feed digestibilities in captive Asian elephants (Elephas maximus). In order to test the suitability of the horse as a nutritional model for elephants, digestibility studies were performed with six captive Asian elephants on six different dietary regimes, using the double marker method with acid detergent lignin as an internal and chromium oxide as an external digestibility marker. Elephants resembled horses in the way dietary supplements and dietary crude fibre content influenced digestibility, in calcium absorption parameters and in faecal volatile fatty acid composition. However, the absolute digestibility coefficients achieved for all nutrients are distinc...
A comparison of the antinociceptive effects of xylazine, detomidine and romifidine on experimental pain in horses. To study the analgesic potency of the alpha2-agonist romifidine in the horse using both an electrical current and a mechanical pressure model for nociceptive threshold testing. In addition, a comparison was made with doses of detomidine and xylazine that produce equivalent degrees of sedation. Methods: Randomized, placebo-controlled, blinded cross-over study. Methods: Six adult Swiss warmblood horses, one mare and five geldings, weighing from 530 to 650 kg and aged 6-15 years. Methods: Nociceptive thresholds were measured using an electrical stimulus applied to the coronary band and using a pn...
Comparison of opioid and alpha-2 adrenergic receptor binding in horse and dog brain using radioligand autoradiography. To test the hypothesis that the distribution, density, and subtype of opioid and alpha (alpha)-2 adrenergic receptors within the central nervous system (CNS) are significantly different between horse and dog. Methods: Prospective experimental study. Methods: Three dogs (3 years of age) and three horses (2-5 years of age). Animals were opioid- and alpha-2 agonist-free at the time of euthanasia. Methods: Brain tissue was obtained at 126 days post-surgery from dogs and 72 days post-surgery from horses. The brains were removed, sectioned coronally into 1-cm slabs, frozen in methylbutane, which was...
Changes in the EEG during castration in horses and ponies anaesthetized with halothane. To identify changes in the amplitude spectrum of the electroencephalogram (EEG) during a standardized surgical model of nociception in horses. Methods: Thirteen entire male horses and ponies referred to Division of Clinical Veterinary Science, Bristol (n = 9) and Department of Clinical Veterinary Medicine (n = 4) for castration. Methods: Following pre-anaesthetic medication with acepromazine, anaesthesia was induced with guaiphenesin and thiopental and maintained with halothane in oxygen. The EEG was recorded continuously using subcutaneous needle electrodes. Additional monitoring comprised EC...
Seasonal changes in plasma concentrations of cecum-derived amines in clinically normal ponies and ponies predisposed to laminitis. To measure concentrations of amines formed in the cecum of clinically normal ponies, determine amine concentrations in plasma samples collected in spring and winter, and compare concentrations of amines and serotonin in plasma samples obtained from clinically normal ponies and ponies predisposed to laminitis. Methods: Cecal contents obtained from 10 ponies euthanatized at an abattoir and blood samples obtained from 42 adult ponies. Methods: Cecal contents were assayed for amines by high-performance liquid chromatography (HPLC). Blood samples were collected at various times of the year from 20 ...
Macroscopic changes in the distal ends of the third metacarpal and metatarsal bones of Thoroughbred racehorses with condylar fractures. To determine changes in the distal ends of the third metacarpal and metatarsal bones (MCIII and MTIII) of Thoroughbred racehorses that had sustained a catastrophic condylar fracture during high-speed exercise. Methods: Fractured and contralateral MCIIIs and MTIIIs from 11 Thoroughbred racehorses that sustained a displaced condylar fracture during racing, both MCIIIs from 5 Thoroughbred racehorses euthanatized because of a catastrophic injury other than a condylar fracture, and both MCIIIs from 5 horses of other breeds that had not been professionally trained or raced. Methods: Macroscopic obse...
Molecular phylogenetics and diagnosis of soil and clinical isolates of Halicephalobus gingivalis (Nematoda: Cephalobina: Panagrolaimoidea), an opportunistic pathogen of horses. Phylogenetic relationships among six isolates of Halicephalobus gingivalis (Stefanski, 1954), a species with pathogenic potential in horses and humans, were evaluated using DNA sequences from the nuclear large-subunit ribosomal RNA (LSU rDNA) gene. Sequences from nematodes obtained from in vitro cultures (soil or clinical sources), or isolated from infected horse tissues, were compared. Gene sequences from a fatal equine clinical case from southern California and a free-living isolate recovered from southern California soil showed no fixed differences. Sequences from isolates representing two ...
Endocrine responses in mares and geldings with high body condition scores grouped by high vs. low resting leptin concentrations. Previous observations from this laboratory indicated that horses with high BCS could have resting plasma leptin concentrations ranging from low (1 to 5 ng/mL) to very high (10 to 50 ng/mL). To study the possible interactions of leptin secretion with other endocrine systems, BCS and plasma leptin concentrations were measured on 36 mares and 18 geldings. From mares and geldings that had a mean BCS of at least 7.5, five with the lowest (low leptin) and five with the highest (high leptin) leptin concentrations were selected. Jugular blood samples were collected twice daily for 3 d from the 20 sele...
Models of fetal growth restriction. The growth of the fetus is determined by substrate supply mostly for mass accretion and energy gain, and by control systems. Experiments with whole animal models will face the following problems: (1) The fetus, like a three compartmental "Russian doll", is at the end of a long supply chain. There are interactions (e.g. hormones) and partitioning of substrates between the compartments. (2) The fetal organism is growing and differentiating at the same time and not in a steady-state. Experimental results thus depend on gestational age. (3) About 75% of animal experiments on fetal growth restricti...
Effects of lactation on metabolic and reproductive hormones in Lipizzaner mares. In this study, growth hormone (GH), insulin-like growth factor 1 (IGF-1), leptin, luteinising hormone (LH) and prolactin were analyzed in mares from late pregnancy throughout lactation (group 1, n=46) and in non-lactating mares (group 2, n=11). Plasma GH concentrations in group 1 mares during gestation and lactation were lower than in mares of group 2 (P<0.05). Highest IGF-1 levels were found in lactating mares in the week of foaling. IGF-1 concentrations decreased continuously thereafter. Plasma leptin concentrations decreased after foaling and, for 4 weeks, were lower in lactating than in...
Relationship between pharmacological induction of estrous and/or ovulation and twin pregnancy in the Thoroughbred mares. The aim of this study was to evaluate the possible relationship of pharmacological induction of estrous and/or ovulation with the occurrence of twin pregnancies in Thoroughbred mares. Out of 680 mares, 356 received one of the following treatments during the estrous cycle in which they became pregnant: injection of 0.5mg of cloprostenol at the ultrasonographic detection of a CL (n=86); injection of 5000 IU human chorionic gonadotropin (hCG) immediately before mating (n=221); injection of 0.5mg of cloprostenol at the ultrasonographic detection of a CL plus injection of 5000 IU hCG immediately be...
Induced lactation with a dopamine antagonist in mares: different responses between ovariectomized and intact mares. The aim of this study was to compare the effects of treatment with repeated injections of sulpiride (a dopamine D2 antagonist) on prolactin secretion and induced lactation in ovariectomized and intact adult mares and to verify if this induction was possible at the beginning and at the end of the birth season. Two experiments were carried out in September [experiment (expt) 1], and in March (expt 2), in France (48 degrees N). In expt 1, three groups of five mares were tested: intact-control, intact-treated and ovariectomized-treated mares. In expt 2, mares previously subjected to artificial pho...
Endocrinological changes before and after removal of the granulosa theca cell tumor (GTCT) affected ovary in 6 mares. To clarify the endocrinological characteristics of the mares with granulosa theca cell tumor (GTCT), peripheral plasma samples from the 6 mares affected with GTCT were collected before and after the surgical removal of the affected ovary. Concentrations of testosterone (T), follicle stimulating hormone (FSH), luteinizing hormone (LH), immunoreactive-inhibin (ir-INH), progesterone (P) and estradiol-17beta (E(2)) in the plasma samples were measured by radioimmunoassay. Before removal of GTCT in all cases, the concentrations of T were significantly higher than those of normal mares at the breedin...
Quantitative analysis of eumelanin and pheomelanin in humans, mice, and other animals: a comparative review. The color of hair, skin, and eyes in animals mainly depends on the quantity, quality, and distribution of the pigment melanin, which occurs in two types: black to brown eumelanin and yellow to reddish pheomelanin. Microanalytical methods to quantify the amounts of eumelanin and pheomelanin in biological materials were developed in 1985. The methods are based on the chemical degradation of eumelanin to pyrrole-2,3,5-tricarboxylic acid and of pheomelanin to aminohydroxyphenylalanine isomers, which can be analyzed and quantitated by high performance liquid chromatography. This review summarizes a...
Schirmer tear test results in normal horses and ponies: effect of age, season, environment, sex, time of day and placement of strips. Tear production was evaluated in 39 horses and 29 ponies using Schirmer tear test strips to determine whether diurnal or weekly fluctuations occur, whether location of strip placement has an effect, if values are the same for both eyes in an animal and whether sex, age, stabling vs. pasture and winter vs. summer had an effect. There was no test in which the raw score was less than 10 mm, although there were many occasions where tear wetting exceeded 35 mm. Analysis of the raw (continuous) scores by linear regression provided no evidence that signalment, housing or season or location of strip p...
Automated plasmapheresis compared with other plasma collection methods in the horse. The purpose of this study was to evaluate plasmapheresis as a method for plasma extraction in comparison with centrifugation or gravity sedimentation. The study was designed as a cross over trial with six Freiberger horses undergoing plasma donation by plasmapheresis followed by whole-blood donation and subsequent plasma production 4 weeks later. Automated plasmapheresis and whole-blood donation were well tolerated in all horses. The plasmapheresis method achieved an almost complete removal of erythrocytes and leucocytes from plasma at all flow rates. After blood bag centrifugation, significan...
Horse hooves and bird feathers: Two model systems for studying the structure and development of highly adapted integumentary accessory organs–the role of the dermo-epidermal interface for the micro-architecture of complex epidermal structures. Accessory organs of the integument are locally modified parts of the potentially feather-bearing skin in birds (e.g., the rhamphotheca, claws, or scales), and of the potentially hairy skin in mammals (e.g., the rhinarium, nails, claws, or hooves). These special parts of the integument are characterised by a modified structure of their epidermal, dermal and subcutaneous layers. The developmental processes of these various integumentary structures in birds and mammals show both similarities and differences. For example, the development of the specialised epidermal structures of both feathers and...
Comparative disposition kinetics and plasma protein binding of gentamicin sulphate in three juvenile animal species. The pharmacokinetics of gentamicin was studied in lambs, calves and foals, respectively after single intravenous (i.v.) injections of 5 mg kg(-1) body weight. The plasma concentration-time curves of gentamicin sulphate were best fitted to follow a two-compartment open model in calves and foals and a three-compartment open model in lambs. Gentamicin showed high plasma level at 5 min post-injection. Then its concentration decreased gradually until its minimum detectable level at 10 and 12 h post-injection in foals and calves, respectively, was reached. In contrast, the plasma concentrations were...
Ultrasonography of peripheral nerves in the normal adult horse. A study of the ultrasonographic appearance and size of the sciatic, tibial, peroneal, suprascapular, radial, median, and ulnar nerves and a comparison with the anatomic size and location of these nerves in the normal adult horse is reported. Cadavers and live horses were studied. Landmarks for localization and techniques for nerve identification are described. The depth and diameter of each nerve at various locations and the success rate in imaging each nerve are reported. Statistically significant correlations were found between anatomically and ultrasonographically measured nerve depths and ...
Effect of administering oxytocin or cloprostenol in the periovulatory period on pregnancy outcome and luteal function in mares. Mares (n = 37) were treated from 4h after breeding through 2 days post-ovulation with oxytocin or cloprostenol. Oxytocin (20 units i.m.) was administered every 6 h and cloprostenol (250 mcg i.m.) daily. Luteal function was impaired for several days following treatment, however, lower progesterone levels among cloprostenol treated mares in this study did not result in decreased pregnancies. Pregnancy outcome at 15 days post-ovulation was not different between the oxytocin (13/18) and cloprostenol (13/19) treatment groups, respectively (P = 0.80). The results of this study indicate cloprostenol ...
