Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Regression Analysis
Regression analysis is a statistical method used to examine the relationship between variables, often employed to predict outcomes or understand associations in equine studies. In the context of horses, regression analysis can be applied to a variety of research areas, including performance metrics, health parameters, and genetic traits. By analyzing data, researchers can identify patterns or correlations that may inform breeding decisions, training regimens, or health interventions. This page compiles peer-reviewed research studies and scholarly articles that explore the application of regression analysis in equine research, focusing on methodologies, findings, and implications for horse management and care.
Morphological analysis of cervical vertebrae in ataxic foals. Morphological differences between cervical vertebrae were statistically analyzed in ataxic foals to clarify abnormal structural factors in the pathogenesis of this problem. At first, multiple regression analysis and cluster analysis were performed with 28 variables in C3-C7 of 39 control foals without lameness. As a result, there were no sex differences in the growth of all cervical vertebral sites, and the most suitable categorization of the age of the foals was 3 clusters of 8 months old or younger, 9-12 months old and 13 months old or older in any sites in the cervical vertebrae. Twenty-eig...
Heterogeneity of pericyte populations in equine skeletal muscle and dermal microvessels: a quantitative study. The objective of this ultrastructural investigation was to determine if populations of pericytes in equine dermal and skeletal muscle capillaries increase in a head-to-foot direction, as has been reported in human skeletal muscles. Samples of equine microvessels were obtained from the longissimus dorsi skeletal muscle 150 cm. from the ground, from the dermis above this muscle, from the extensor carpi radiali muscle at 55 cm. from the ground, from the dermis adjacent to that muscle, and from dermis 15 cm. from the ground, just above the hoof wall. Tissues were processed for transmission electro...
Measurement by ELISA of equine alpha-1-proteinase inhibitor in uterine flushings from mares. An enzyme linked immunosorbent assay (ELISA) was developed and used to estimate the concentrations of the serine proteinase inhibitor, alpha-1 proteinase inhibitor (API), in uterine flushings recovered from mares at different stages of the oestrous cycle and before and after the induction of experimental endometritis. There was a significant increase in the concentrations of API and albumin relative to total protein in flushings recovered during oestrus compared with dioestrus but no difference was observed in the concentrations of these proteins relative to total protein before and after the ...
Measurements of heart scores and heart weights in horses of two different morphic body types. Heart scores (the arithmetic mean of the QRS durations of the three bipolar limb leads for 10 cycles) and heart weights were determined from five draft type horses and five racing type horses, and evaluated for relationships between heart score and heart size within and between the two different types of horses. Horses were killed using a captive bolt gun, and actual heart weights were recorded using an electronic digital scale. The linear regression equation for heart weight versus heart score had a significant (P 0.05) different than zero. There was no significant (P > 0.05) difference f...
Cerebrospinal fluid variables in clinically normal foals from birth to 42 days of age. To determine the effects of age on each analyte, CSF variables were evaluated in healthy foals from birth through 42 days of age. Cerebrospinal fluid was collected from 14 clinically normal, naturally delivered cross-bred foals and was analyzed for glucose, sodium, potassium, magnesium, and total protein concentrations, total and differential WBC counts, RBC count, and lactate dehydrogenase, aspartate transaminase, and creatine kinase activities. Samples were collected in 3 foals < 48 hours old, and at 11 to 14 days of age in 4 foals, 21 to 22 days of age in 3 foals, and 31 to 42 days of ag...
Skeletal muscle characteristics in 2 year-old race-trained thoroughbred horses. Skeletal muscle samples were obtained by needle biopsy from two depths of the m. gluteus medius of 50, young race-trained thoroughbred racehorses. Histochemical and biochemical characteristics of the muscle samples were analysed. Fibres were classified as type I, type IIa or type IIb on the basis of the pH dependent lability of the myosin ATPase reaction. The activities of citrate synthase (CS) and glycogen phosphorylase (Phos) were determined. Muscle fibre composition varied markedly between deep and superficial muscle samples and this was reflected in differences in the activities of citrate...
The validity of swimming training for two-year-old thoroughbreds. To investigate the validity of swimming training, the following matters were considered: 1) changes in the performance capacity, 2) changes in the constitution and 3) frequency of locomotor diseases. These were evaluated during a training program including both conventional exercise on a track and swimming. In this study, 24 two-year-old thoroughbred horses were studied, and divided into the following three groups: Group A, trained by only running; Group B, trained by running plus a gradual increase in swimming; Group C, trained by running plus constant swimming. As a result of standardized ex...
Geographical variation of seropositivity to Ehrlichia risticii (equine monocytic ehrlichiosis) of horses in New York state. A total of 2,579 serum samples from horses in New York state during 1985-1986 were examined for seropositivity to Ehrlichia risticii using the indirect fluorescent antibody technique. Cluster analysis statistical technique was used to group counties according to their estimated EME-disease rate (seropositive proportion of sampled horses). Counties were clustered into 4 groups of different EME-disease rates, representing high (86% seropositive), medium (66% seropositive), medium-low (47% seropositive) and low (6% seropositive) risk regions. The logistic regression statistical technique was used...
Application to cows and horses of Spotchem, a dry-chemistry blood analyzer for use in veterinary clinics. The usefulness of a dry-chemistry blood analyzer, Spotchem SP-4410 (SP-4410) in a veterinary clinic for analysis of bovine and equine blood chemistry was studied. We quantitated total protein (TP), albumin (Alb), total bilirubin (T-Bil), blood urea nitrogen (BUN), total cholesterol (T-Cho), glucose (Glu), calcium (Ca), aspartate aminotransferase (AST), gamma-glutamyltransferase (GGT), creatinine phosphokinase (CPK), and alkaline phosphatase (ALP) in bovine sera. Each sample was assayed with both the SP-4410 and an automated blood analyzer which served as a wet-chemistry reference system, and t...
Epidemiology of equine motor neuron disease. Equine motor neuron disease (EMND) is a newly recognized neurodegenerative disorder of bulbospinal motor neurons in the horse. We conducted a case-control study to identify intrinsic factors associated with the risk of this disorder. Seventy-four cases and 160 controls were assembled. Controls included horses diagnosed with equine protozoal myelitis, equine degenerative myeloencephalopathy, and cervical stenotic myelopathy during the same time period as the cases. Logistic regression analysis was used to evaluate the association of each hypothesized factor while simultaneously controlling for ...
Relationship of serum total calcium to serum albumin in dogs, cats, horses and cattle. A retrospective study was performed in order to assess the relationship between serum calcium and serum albumin concentrations in domestic animals. Results of 9041 canine, 1564 feline, 2917 equine, and 613 bovine serum samples from hospitalized patients were examined by regression analysis. Subpopulations of cases with concurrent elevations in creatinine or that were less than six months of age were evaluated separately. Statistically significant linear relationships between calcium and albumin concentrations were established for each species (p <0.05). The coefficients of determination (r(...
A retrospective evaluation of laminitis in horses. Case records of 202 horses treated for laminitis were reviewed with the intent of determining the long-term outcome and correlating this with digital radiographic findings and with the degree of pain associated with the laminitis. At long-term follow-up 57 horses had returned to athletic soundness (Group 1), 20 horses were intermittently lame (Group 2), 19 horses had permanent severe lameness (Group 3), 97 were dead (Group 4), and 9 were lost to follow up. Using simple regression analysis, functional outcome did not correlate with the degree of rotation (R2 = 0.004) or the presence of distal d...
Stride characteristics of overground versus treadmill locomotion in the saddle horse. The purpose of this study was to compare the velocity-dependent changes in stride length and stride frequency of horses performing the same incremental exercise test first on a track with a rider and then on a treadmill with a 0 and 3.5% slope successively. Seven French saddle horses undertook the exercise test which consisted of 5 stages of increasing speed for 3 min each with 1 min rest between each stage (1.6, 4.2, 8.3, 9.2 and 10 m/s). The horses were recorded by use of a video camera, and the tapes were analysed with regard to gait parameters. At 1.6, 8.3, 9.2 and 10 m/s, stride frequenci...
Gallop kinematics of Olympic three-day event horses. Limb contact variables of the gallop of 3-day event horses were determined for competitors in the 1988 Seoul Summer Olympic Games. Horses were filmed during the steeplechase, phase B of the speed and endurance test on day 2 of competition. Two 16-mm high-speed cameras were aimed perpendicularly to the direction of subject motion along a straightaway on the steeplechase track, filmed at 200 frames/s. Thirty-four of 48 competitors were filmed and 108 gallop strides analyzed. Velocity (VEL) averaged 12.09 +/- 0.10 m/s (mean +/- SE), stride length (SL) 6.04 +/- 0.05 m and stride frequency (SF) 2.0...
Strain of the musculus interosseus medius and its rami extensorii in the horse, deduced from in vivo kinematics. The in vivo strains of the musculus interosseus medius (suspensory ligament) and its rami extensorii (extensor branches) in the forelimb of the horse were determined from angular changes of the metacarpophalangeal and the distal interphalangeal joints. For this purpose, regression models were fitted to strains and joint angle combinations measured in in vitro limb loading experiments. The in vivo strains were computed from the kinematics of 8 horses at the walk, the trot and the canter. It was found that the extensor branches were strained about 1.0% at hoof impact, which indicates that they p...
Prognostic indicators for horses with duodenitis-proximal jejunitis. 75 horses (1985-1989). The medical records of 75 horses with duodenitis-proximal jejunitis (DPJ) were reviewed. Ages, physical parameters, laboratory values, and treatment data were compared between horses surviving DPJ and horses not surviving DPJ (Table 1). Fifty of 75 horses (66.6%) survived. Sixty-six horses (88.0%) were managed with medical treatment alone and nine horses (12.0%) were managed with medical treatment plus surgical intervention. Using a logistic regression model, the association of each of the 19 physical and laboratory parameters with death was evaluated retrospectively in the 75 horses. Three pa...
Retrospective evaluation of factors associated with the risk of seropositivity to Ehrlichia risticii in horses in New York State. A retrospective study was designed to determine the distribution of equine monocytic ehrlichiosis among the equine population in New York state, and to identify factors associated with risk of disease. Serum samples submitted to the diagnostic laboratory of the university during the period from January 1985 through December 1986 were examined for antibodies to Ehrlichia risticii, using the indirect fluorescent antibody technique. Factors evaluated included geographic origin and date of submission of the sample, and age, breed, and sex of the horse. Logistic regression analysis was used to iden...
Estimation of the carnosine content of different fibre types in the middle gluteal muscle of the thoroughbred horse. 1. Skeletal muscle samples were obtained by needle biopsy from one of two depths of the m. gluteus medius in a group of twenty race-trained thoroughbred horses. 2. The content of carnosine was determined in each muscle sample, part of which was used for histochemical analysis. Fibres were classified as type I, type IIA or type IIB on the basis of the pH dependent lability of the myosin ATPase reaction. 3. Muscle samples with a higher type II fibre section area (FSA) have a higher carnosine content than those with a higher type I FSA. 4. Multiple linear regression analysis was used to estimate ...
Temporal effects of plasmapheresis on serum proteins in horses. The temporal response of blood and serum proteins to chronic plasmapheresis was determined in 8 horses used in a commercial antibody enterprise. Plasmapheresis of between 4 and 11 L induced significant decreases in total protein, albumin, and IgG values. With the exception of a high hematocrit value for the first postplasmapheresis blood sample, there were no changes in erythrocyte or leukocyte measurements, and no changes in the proportions of serum protein in an electrophoretic profile. Regression equations generated for recovery of proteins after plasmapheresis indicated a return to preplas...
Ultrasound speed in the metacarpal cortex–a survey of 347 thoroughbreds in training. Transmission ultrasound speed was determined in the third metacarpal bone of 347 Thoroughbred racehorses in training. In addition to direct measurement of apparent ultrasound speed and lateral bone diameter, several derived parameters were estimated (cortical ultrasound speed, corticomedullary ratio and cortical cross-sectional area). Multiple regression equations were developed for each ultrasound measurement using the explanatory variables: sex, age, duration and intensity of training, preparation number and previous shin soreness. The horses (114 females, 82 entire males and 151 geldings ra...
Prognostic variables for survival of neonatal foals under intensive care. The costly nature of intensive care for neonatal foals prompted a study of predictive variables for survival in a referral hospital. Applying stepforward logistic regression to parameters that differed significantly (P less than 0.10) between survivors (S) and nonsurvivors (NS) in a retrospective study (n = 56), two variables retained statistical significance [anion gap (AG, P = 0.0047) and venous PO2 (PvO2, P = 0.0342)], thus forming the basis for a predictive equation for survival: the Pn (probability of NS) = eA/(1 + eA) where A = -1.46 - 0.107 (PvO2) + 0.213 (AG). The predictive equation w...
Comparison of high-performance liquid chromatography with a radiometric assay for determination of the effect of intra-articular administration of corticosteroid and saline solution on synovial fluid hyaluronate concentration in horses. Two recently developed direct methods, radioassay-125I-labeled hyaluronic acid binding protein (125I-HABP)- and high-performance liquid chromatography (HPLC), were used to assess and compare the concentration of hyaluronate (HA) in synovial fluid of horses. Also determined were changes in the HA concentration in an experimental treatment model involving physiologic saline solution (PSS)-irrigated or methylprednisolone acetate-injected tarsocrural joints of clinically normal horses. Serum HA concentration was determined simultaneously, using the 125I-HABP assay. Synovial fluid HA concentration ...
Measurement of cardiac dimensions with two-dimensional echocardiography in the living horse. Two-dimensional echocardiography (2DE) was performed on 22 unsedated Thoroughbred and part Thoroughbred horses weighing between 411 and 650 kg to establish normal reference values for 2DE measurements. Animals stood during examinations performed with a 3.5 MHz mechanical sector transducer using various transducer positions and tomographic planes. Right ventricular diameter (RVD), ventricular septal thickness (VSTh), aortic diameter (AoD), area of the chordal lumen of the left ventricle (CTA), left ventricular diameter (LVD) and left atrial diameter (LAD) were determined at ventricular end-dias...
Season but not age affects Sertoli cell number in adult stallions. To evaluate the effect of age and season on Sertoli cell number per paired testes, ratio of germ cells per Sertoli cell, and daily sperm production, testes were obtained from 184 adult (4-20 yr) stallions at slaughter throughout one year. Numbers of Sertoli cells or germ cells were derived from nuclear volume density, volume of individual nuclei, and parenchymal volume. Germ cell to Sertoli cell ratios were calculated from cell numbers. Regression analysis was used to detect age-related differences in the breeding season (May-Jul) or throughout the year. A two-way analysis of variance was used...
Left ventricular volume determination in the horse by two-dimensional echocardiography: an in vitro study. This study was designed to evaluate the accuracy of two-dimensional echocardiography (2DE) in determining the left ventricular volume (LVV) of the horse in vitro. After examining the shape of the left ventricular silicon rubber casts of four equine hearts, two modified Simpson's rule methods (Model A and Model B) as combinations of conical shapes and one biplane area-length method as a single cone (Model C) were chosen for volume calculations. One long axis and three short axis planes were used for linear and area 2DE measurements, respectively. The ventricular length (L) was calculated from t...
Failure of pH to predict ionized calcium percentage in healthy horses. Blood, serum, and plasma total calcium concentrations and plasma and serum ionized calcium concentrations were anaerobically determined by use of a calcium-specific electrode for samples obtained from 39 healthy horses. Mean (+/- SD) serum ionized calcium concentration was 6.6 +/- 0.3 mg/dl (1.6 +/- 0.1 mmol/L) and the mean serum ionized calcium percentage was 58.2 +/- 3.4%. Serum ionized calcium percentage was not significantly correlated with serum pH. Plasma ionized calcium percentage was weakly correlated with plasma pH (r = -0.480; P less than or equal to 0.05). Ionized calcium concentrat...
Determination of the relationship between sperm morphologic classifications and fertility in stallions: 66 cases (1987-1988). The analysis of breeding records and sperm morphologic classifications from ejaculated semen during 99 stallion seasons, over a 2-year period, revealed a significant correlation (r = 0.34, P less than 0.01) between the percentage of morphologically normal sperm in ejaculates and the per cycle fertility estimate of the stallions studied. In addition, the percentage of sperm classified as having major defects (abnormal heads, proximal droplets, and abnormal midpieces) was significantly inversely correlated (r = -0.36, P less than 0.01) with the same fertility estimates. Multiple variable regress...
Effect of age on isoproterenol-induced maximal heart rate in horses. The effect of age on maximal heart rate induced by IV infusion of isoproterenol was studied in 19 healthy, sedentary, normothermic horses ranging in age from 0.25 to 9.90 years. Isoproterenol was administered IV (1.0 micrograms/kg of body weight/min) for 3 minutes, and the heart rate attained during the last 30 seconds of the infusion was determined. Linear regression of the maximal heart rate on age suggested that the rate decreased with age in a trend described by the equation: maximal heart rate (beats/min) = 209.63 - 3.28 x age (years). The regression coefficient (r) for this relation was ...
Multifactorial inheritance of common white markings in the Arabian horse. The results of a previous study were compatible with the hypothesis that common white facial markings in the Arabian horse have a multifactorial mode of inheritance. I expanded that study to (1) include the legs and therefore obtain insight into the heritability of common white markings in all peripheral regions (face and legs) of the Arabian horse and (2) investigate the influence of sex and the genotypes that produce the bay and chestnut phenotypes on the variation in common white markings. Both studies were based on computerized data obtained from the Arabian Horse Registry of America, Inc....
A computer-derived protocol using recursive partitioning to aid in estimating prognosis of horses with abdominal pain in referral hospitals. In order to determine which variables are useful and accurate in estimating prognosis in horses with abdominal pain, data were analyzed from 231 horses presented at a veterinary teaching hospital. Using multiple stepwise discriminant analysis in a recursive partition model, we obtained a decision protocol that identified survivors and nonsurvivors. The prevalence of survivors was 61% in this population. The sensitivity, specificity, and positive and negative predictive values of this model were 71, 83, 87 and 65%, respectively. This decision protocol was validated by Jackknife classification a...
