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.
Mammalian male mutation bias: impacts of generation time and regional variation in substitution rates. In mammals, males undergo a greater number of germline cell divisions compared with females. Thus, the male germline accumulates more DNA replication errors, which result in male mutation bias-a higher mutation rate for males than for females. The phenomenon of male mutation bias has been investigated mostly for rodents and primates, however, it has not been studied in detail for other mammalian orders. Here we sequenced and analyzed five introns of three genes (DBX/DBY, UTX/UTY, and ZFX/ZFY) homologous between X and Y chromosomes in several species of perissodactyls (horses and rhinos) and of...
Diversity and distribution of Escherichia coli genotypes and antibiotic resistance phenotypes in feces of humans, cattle, and horses. Escherichia coli is the most completely characterized prokaryotic model organism and one of the dominant indicator organisms for food and water quality testing, yet comparatively little is known about the structure of E. coli populations in their various hosts. The diversities of E. coli populations isolated from the feces of three host species (human, cow, and horse) were compared by two subtyping methods: ribotyping (using HindIII) and antibiotic resistance analysis (ARA). The sampling effort required to obtain a representative sample differed by host species, as E. coli diversity was consis...
Follicle selection in cattle and horses: role of intrafollicular factors. The eminent event in follicle selection during a follicular wave in monovular species is diameter deviation, wherein one follicle continues to grow (developing dominant) and other follicles (subordinates) begin to regress. In cattle, the IGF system, oestradiol and LH receptors are involved in the intrafollicular events initiating deviation as indicated by the following: (1) concentrations of free IGF-I and oestradiol in the follicular fluid and number of LH receptors in the follicular wall increase more dramatically in the future dominant follicle than in the future subordinate follicles befor...
Genome of horsepox virus. Here we present the genomic sequence of horsepox virus (HSPV) isolate MNR-76, an orthopoxvirus (OPV) isolated in 1976 from diseased Mongolian horses. The 212-kbp genome contained 7.5-kbp inverted terminal repeats and lacked extensive terminal tandem repetition. HSPV contained 236 open reading frames (ORFs) with similarity to those in other OPVs, with those in the central 100-kbp region most conserved relative to other OPVs. Phylogenetic analysis of the conserved region indicated that HSPV is closely related to sequenced isolates of vaccinia virus (VACV) and rabbitpox virus, clearly grouping to...
Aspiration of oocytes from transitional, cycling, and pregnant mares. The aim of this study was to compare the efficacy of three approaches for recovering equine oocytes via transvaginal ultrasound-guided follicular aspiration. Fourteen mares were used as oocyte donors during the spring transition period and physiologic breeding season, and 11 mares were bred for use as oocyte donors during early gestation. In all mares, large (>20 mm) and small (10-20 mm) follicles were aspirated in eight rounds every 10-11 days. In each of the four rounds during the transition period, half the mares received 12.5 mg eFSH once daily for 4 days prior to aspiration. For each of t...
Follicle deviation and diurnal variation in circulating hormone concentrations in mares. The temporal relationships between follicle deviation and systemic hormone concentrations were studied in mares. Blood samples were obtained at 01:00, 07:00, 13:00, and 19:00 h from nine mares throughout an interovulatory interval. Diurnal variation in progesterone occurred on Days 4-12 and in LH on Days 4 and 5; the lowest concentration for both hormones was at 13:00 h. Ultrasonically observed deviation in the ovulatory follicular wave began on Day 15.7+/-0.5 (ovulation=Day 0). An increase (P<0.002) in LH began on Day 14 before the beginning of deviation, and an increase (P<0.05) in est...
Comparison of two selective media for the recovery, isolation, enumeration and differentiation of Rhodococcus equi. The use of selective media to facilitate the isolation of Rhodococcus equi from environmental and clinical samples has aided studies of the ecology of R. equi and the epidemiology of disease caused by R. equi. Here, we compared the efficacy of two selective media (NANAT and modified CAZ-NB) for the recovery of six defined strains of R. equi and for the isolation and enumeration of both avirulent and virulent R. equi from 60 paired soil samples from horse farms using colony blotting and DNA hybridisation. No difference was found between the two media in the recoverability of defined strains of ...
[“Horses no longer have wings”. The chapter on the anatomy of a horse from a hippology manuscript by Nakula]. The first part of this paper gives a short historical survey of veterinary medicine in India starting from vedic times. The knowledge about hippiatry was highly valued since horses played an important role in warfare. The review of authors and publications on Indian hippiatry and hippology is followed by a synopsis on these traditions in Europe. The second part of this article includes further references and research on the Aśvaśăstra of Nakula and a translation of chapter 4 describing the anatomy of the horse.
IdeE, an IgG-endopeptidase of Streptococcus equi ssp. equi. Streptococcus equi ssp. equi is the causative agent of strangles, a highly contagious and serious disease in the upper respiratory tract of horses. The present study describes the characterization of IdeE, a homolog of the secreted IgG-specific protease IdeS/Mac of Streptococcus pyogenes. The activity of IdeE is compared with the activity of IdeZ, the corresponding enzyme of the closely related S. equi ssp. zooepidemicus. A study of the proteolytic activity of recombinant IdeE and IdeZ on IgG from a selection of mammals shows that only antibodies containing the substrate site of IdeS/Mac are c...
Fertility of frozen-thawed stallion semen cannot be predicted by the currently used laboratory methods. The aim of the project was to use current simple and practical laboratory tests and compare results with the foaling rates of mares inseminated with commercially produced frozen semen. In Exp. 1, semen was tested from 27 and in Exp. 2 from 23 stallions; 19 stallions participated in both experiments. The mean number of mares per stallion in both experiments was 37 (min. 7, max. 121). Sperm morphology was assessed and bacterial culture performed once per stallion. In Exp. 1, progressive motility after 0, 1, 2, 3, and 4 h of incubation using light microscopy, motility characteristics measured wit...
High-resolution gene maps of horse chromosomes 14 and 21: additional insights into evolution and rearrangements of HSA5 homologs in mammals. High-resolution physically ordered gene maps for equine homologs of human chromosome 5 (HSA5), viz., horse chromosomes 14 and 21 (ECA14 and ECA21), were generated by adding 179 new loci (131 gene-specific and 48 microsatellites) to the existing maps of the two chromosomes. The loci were mapped primarily by genotyping on a 5000-rad horse x hamster radiation hybrid panel, of which 28 were mapped by fluorescence in situ hybridization. The approximately fivefold increase in the number of mapped markers on the two chromosomes improves the average resolution of the map to 1 marker/0.9 Mb. The improv...
Limb fractures more common in French than British jockeys. French jockeys suffer more severe injuries when they fall off their horses than their British counterparts. While it has been shown that jockeys suffer high rates of fatal and non-fatal injuries, little is known about differences in injury rates between countries. To investigate this, researchers from Australia, France and the UK used prospectively collected data on the rates of fatal and non-fatal injuries in flat and jump jockeys in France and compared them with data from the UK.
Comparison of mechanical debridement and radiofrequency energy for chondroplasty in an in vivo equine model of partial thickness cartilage injury. The purpose of this study was to develop a long-term model of cartilage injury that could be used to compare the effects of radiofrequency energy (RFE) and mechanical debridement as a treatment. Methods: Partial thickness fibrillation of patellar cartilage was created in 16 mature ponies. Three months after the initial surgery all injured patellae were randomly selected to receive one of the four treatments (n = 8/treatment): (1) control, (2) mechanical debridement with a motorized shaver, (3) TAC-CII RFE probe, and (4) CoVac 50 RFE probe. The ponies were euthanized 22 months after treatment. ...
Cholesterol oxidase (ChoE) is not important in the virulence of Rhodococcus equi. To analyze further the role in virulence of the prominent cholesterol oxidase (ChoE) of Rhodococcus equi, an allelic exchange choE mutant from strain 103+ was constructed and assessed for virulence in macrophages, in mice, and in foals. There was no difference between the mutant and parent strain in cytotoxic activity for macrophages or in intra-macrophage multiplication. No evidence of attenuation was obtained in macrophages and in mice, but there was slight attenuation apparent in four intra-bronchially infected foals compared to infection of four foals with the virulent parent strain, based...
Pilot study to evaluate 3 hygiene protocols on the reduction of bacterial load on the hands of veterinary staff performing routine equine physical examinations. Reduction factors (RFs) for bacterial counts on examiners' hands were compared when performing a standardized equine physical examination, followed by the use of one of 3 hand-hygiene protocols (washing with soap, ethanol gel application, and chlorohexidine-ethanol application). The mean RFs were 1.29 log10 and 1.44 log10 at 2 study sites for the alcohol-gel (62% ethyl alcohol active ingredient) protocols and 1.47 log10 and 1.94 log10 at 2 study sites for the chlorhexidine-alcohol (61% ethyl alcohol plus 1% chlorhexidine active ingredients) protocols, respectively. The RFs were significantly d...
Relationship between trace elements status in mane hair and atrial fibrillation in horse. To investigate the relationships between trace elements concentrations in hair and atrial fibrillation (AF) in horses, concentrations of nineteen trace elements were detected in hair using the particle induced X-ray emission (PIXE) method. The horses were assigned to either control (n=22, no abnormalities) or AF groups (n=5) based on electrocardiograph findings. The mean concentrations of Ca and Zn in the hair of the AF group were significantly higher than those in the control group. The Zn/Cu ratio of the hair in the AF group (29.8 +/- 5.5) was significantly higher than that in the control gr...
Cryopreservation of horse semen under laboratory and field conditions using a Stirling Cycle freezer. A Stirling Cycle freezer has been developed as an alternative to conventional liquid nitrogen controlled rate freezers. Horse semen samples were cooled in 0.25 ml straws and 15 ml bags in the Stirling Cycle freezer under laboratory conditions and as a portable device, powered from a car battery. For comparison, straws were frozen in a conventional liquid nitrogen controlled rate freezer. Upon thawing, motility and viability of samples frozen in the Stirling Cycle freezer were not significantly different when compared to samples frozen in the liquid nitrogen freezer. Unlike liquid nitrogen syst...
Ethnoveterinary medicines used for horses in Trinidad and in British Columbia, Canada. This paper investigates the commonalities in ethnoveterinary medicine used for horses between Trinidad (West Indies) and British Columbia (Canada). These research areas are part of a common market in pharmaceuticals and are both involved in the North American racing circuit. There has been very little research conducted on medicinal plants used for horses although their use is widespread. The data on ethnoveterinary medicines used for horses was obtained through key informant interviews with horse owners, trainers, breeders, jockeys, grooms and animal care specialists in two research areas: Tr...
Occurrence of Strongylidae (Nematoda: Strongyloidea) in Polish horses “tarpans” from Popielne Reserve. The study was performed to evaluate intensity of strongylid infection in stabled tarpans using the method of collecting worms after anthelmintic treatment and in wild tarpans from Popielne reserve on the basis of faecal examination. After treatment with ivermectin 12 cyathostomes and one large strongyle species were recovered from the faeces of two tarpans. The most abundant cyathostome species were C. catinatum, C. pateratum, C. longibursatum, C. nassatum and C. coronatus. A higher intensity of infections with small strongyles (cyathostomes) was found in stabled group than in the group from t...
Exclusion of linkage of the RYR1, CACNA1S, and ATP2A1 genes to recurrent exertional rhabdomyolysis in Thoroughbreds. To determine whether there was genetic linkage between the recurrent exertional rhabdomyolysis (RER) trait in Thoroughbred horse pedigrees and DNA markers in genes (the sarcoplasmic reticulum calcium release channel [RYR1] gene, the sarcoplasmic reticulum calcium ATPase [ATP2A1] gene, and the transverse tubule dihydropyridine receptor-voltage sensor [CACNA1S] gene) that are important in myoplasmic calcium regulation. Methods: 34 horses in the University of Minnesota RER resource herd and 62 Thoroughbreds from 3 families of Thoroughbreds outside of the university in which RER-affected status wa...
The use of a random regression model to account for change in racing speed of German trotters with increasing age. In a genetic analysis of German trotters, the performance trait racing time per km was analysed by using a random regression model on six different age classes (2-, 3-, 4-, 5- and 6-year-old and older trotters; the age class of 3-year-old trotters was additionally divided by birth months of horses into two seasons). The best-fitting random regression model for the trait racing time per km on six age classes included as fixed effects sex, race track, condition of race track (fitted as second-order polynomial on age), distance of race and each driver (fitted as first-order polynomial on age) as ...
Gross, histologic, and gene expression characteristics of osteoarthritic articular cartilage of the metacarpal condyle of horses. To identify patterns and correlations of gross, histologic, and gene expression characteristics of articular cartilage from horses with osteoarthritis. Methods: 10 clinically normal horses and 11 horses with osteoarthritis of the metacarpal condyles. Methods: Metacarpophalangeal joints were opened and digitally photographed, and gross lesions were scored and quantified. Representative cartilage specimens were stained for histologic scoring. Total RNA from dorsal and palmar articular surfaces was processed on an equine gene expression microarray. Results: Histologic scores were greater in both ...
Serum concentrations of calcium, phosphorus, magnesium and calciotropic hormones in donkeys. To provide reference values for serum biochemical variables that are used for evaluation of mineral metabolism in donkeys and compare values with those in horses. Methods: 18 donkeys and 18 horses. Methods: Total calcium (tCa), total magnesium (tMg), and inorganic phosphorus (P) concentrations were measured in serum samples via spectrophotometry. Ionized calcium (iCa) and magnesium (iMg) concentrations were quantified with selective electrodes. By use of a micropartition system, tCa and tMg were fractionated to separate protein-bound (pCa, pMg) and ultrafiltrable fractions. Complexed calcium (...
Comparative analysis of cytokine gene expression in cerebrospinal fluid of horses without neurologic signs or with selected neurologic disorders. To determine gene transcription for cytokines in nucleated cells in CSF of horses without neurologic signs or with cervical stenotic myelopathy (CSM), West Nile virus (WNV) encephalitis, equine protozoal myeloencephalitis (EPM), or spinal cord trauma. Methods: 41 horses (no neurologic signs [n = 12], CSM [8], WNV encephalitis [9], EPM [6], and spinal cord trauma [6]). Methods: Total RNA was extracted from nucleated cells and converted into cDNA. Gene expression was measured by use of real-time PCR assay and final quantitation via the comparative threshold cycle method. Results: Cytokine genes ...
[PCR-RFLP analysis of the mtDNA Cytb gene in three different horse breeds]. Restriction endonucleases, namely BamH I, Taq I, Hae III, Rsa I and Hinc II, were used to analyze the polymorphism of partial mtDNA Cytb gene sequences from 256 horses 6 types (Thoroughbred, Sanhe, Wuzhumuqin, Xinihe, Wushen and Pony) including the imported breed, cultivated breed and local breed. The products of endonuclease digestion were run on 8% non-denaturing polyacrylamide gel electrophoresis and detected by silver staining. Results indicated BamH I and Taq I polymorphism. In all 7 restriction patterns were defected that could be sorted into 3 haplotypes, of which haplotypes I and III w...
Prevalence of gastric squamous ulceration in horses with abdominal pain. Prevalence of gastric ulcerations differs widely according to breed and circumstances of management. Further study of the biological variables involved is required in order to identify more exactly the reasons for the reported range. Objective: The objectives of this present study, which do not appear to have been addressed previously in the literature, were 1) the prevalence of gastric ulceration in horses with abdominal pain. 2) difference in prevalence in horses responding to medical therapy and those requiring surgical intervention. 3) whether gastric ulceration is associated with any part...
Scintigraphic evaluation of the proximal metacarpal and metatarsal regions in clinically sound horses. In recent years, pain arising from the proximal metacarpal and metatarsal regions has become well recognized as a cause of lameness and various disease entities have been identified. However, our knowledge of normal patterns of radiopharmaceutical uptake is limited, making interpretation of images problematic. It is therefore important to characterize normal patterns of radiopharmaceutical uptake at specific sites to ensure valid interpretation of images in clinical cases with subtle lesions. The purpose of this study was to describe the pattern of radiopharmaceutical uptake in the proximal me...
Effect of ACTH (tetracosactide) on steroid hormone levels in the mare. Part A: effect in intact normal mares and mares with possible estrous related behavioral abnormalities. Ovariectomized mares and mares with inactive ovaries may show signs of estrus. The reason behind this phenomenon is not clear; however, steroid hormones of adrenal origin have been suggested. Moreover, aberrant adrenal hormone production has been implied as a reason why some intact mares may change behavior. In the present study, the effect of ACTH on plasma levels of cortisol, progesterone, androstenedione and testosterone was investigated in intact mares with normal estrous behavior ('controls', n=5) and intact mares that according to their owners showed deviant estrous behavior ('problem' m...
Effect of ACTH (tetracosactide) on steroid hormone levels in the mare. Part B: effect in ovariectomized mares (including estrous behavior). The mare is the only non-primate species known to display estrous signs after ovariectomy and adrenal hormones have been implicated as a possible cause. Moreover, in several species, estradiol seems to have a stimulatory effect on the hypothalamic-pituitary-adrenal axis. The aim of the present study was to compare the effect of ACTH (tetracosactide) on pertinent hormones [cortisol, progesterone, androstenedione, testosterone (intact and ovariectomized mares) and estradiol (ovariectomized mares only)] in intact mares in estrus with the same mares after ovariectomy (n=5). Blood samples were coll...
