Omneity® Pellets
All-In-One Vitamin & Mineral Pellet
Topic:Genetics
Genetics in horses encompasses the study of hereditary traits and the genetic makeup that influences various characteristics and health conditions in equine populations. This field involves the analysis of genes and their functions, inheritance patterns, and the impact of genetic variations on traits such as coat color, performance ability, and susceptibility to diseases. Research in equine genetics employs techniques such as genome mapping, sequencing, and genetic testing to identify specific genes and mutations associated with these traits. This page gathers peer-reviewed research studies and scholarly articles that explore the genetic basis of equine traits, the methodologies used in genetic research, and the implications for breeding, health management, and conservation of horse breeds.
Microtubular mass defect of spermatozoa in the stallion. A microtubular mass (MM) defect was found in the spermatozoa of 7 Standardbred stallions; 3 stallions were sons of the same sire. Two of these 3 stallions and 2 other stallions (for a total of 4 out of the 7 stallions) were considered subfertile when the defect was first observed. Fertility improved with time, either during the first breeding season or when a given stallion was used less frequently; however, the MM defect persisted, consisting of tortuous arrays of small abnormal microtubules visible only by transmission electron microscopy. The MM probably contained the protein tubulin as ind...
Common plasmid encoding resistance to ampicillin, chloramphenicol, gentamicin, and trimethoprim-sulfadiazine in two serotypes of Salmonella isolated during an outbreak of equine salmonellosis. An outbreak of equine salmonellosis occurred at the Veterinary Medical Teaching Hospital, University of California, Davis, between June 1981 and March 1982. Forty-four horses were infected with Salmonella saint-paul, a serotype rarely isolated from animals at the university before the outbreak. Unlike the isolates of S saint-paul obtained at the beginning of the outbreak, almost all strains isolated near the end were resistant to ampicillin, cephalothin, chloramphenicol, gentamicin, kanamycin, sulfadiazine, trimethoprim, and trimethoprim-sulfadiazine. A conjugal-resistance plasmid (R-plasmid) ...
Characterization of a novel Na+-independent amino acid transporter in horse erythrocytes. Horse erythrocytes are polymorphic with respect to L-alanine permeability. The present investigation compared the specificity, kinetics and cation-dependence of erythrocyte amino acid transport in two groups of thoroughbred horses, those with erythrocyte L-alanine permeabilities in the range 5-15 mumol/h per litre of cells (0.2 mM extracellular L-alanine, 37 degrees C) (transport-negative type) and those with L-alanine permeabilities in the range 450-700 mumol/h per litre of cells (transport-positive type). Transport-positive cells are shown to possess a novel high-affinity, stereospecific, Na...
Hybrids from equine LH: alpha enhances, beta diminishes activity. LH hybrids were prepared by combining eLH alpha and eLH beta with the corresponding subunits of oLH, pLH and hCG. Recombinants were isolated by gel filtration and assessed by SDS-polyacrylamide gel electrophoresis under both dissociating and non-dissociating conditions. All combinations of subunits produced hybrid LH molecules. Hybrids prepared by combining eLH beta with oLH alpha, pLH alpha or hCG alpha were very inactive in rat radioligand and Leydig cell in vitro bioassays. Hybrids prepared with eLH alpha were very active in both assays. The greatest potentiating activity was observed when ...
[Hyalurodinase activity of beta-hemolytic streptococci of the Lancefield group C]. A total of 110 strains of beta-hemolytic streptococci, belonging to serogroup C (Lancefield), isolated from horses (71 S. zooepidemicus, 27 S. equisimilis and 12 S. equi) as well as 5 reference strains were tested for their ability to produce hyaluronidase. The determinations were carried out in a culture test on agarose gel and in a liquid test system (turbidity test according to DiFerrante). The results of both methods used showed that the three Streptococcus species could be differentiated by the relative quantitative determination of hyaluronidase activity. S. equisimilis strains produce 5...
The biosynthesis of 3 beta-hydroxy-5,7-androstadien-17-one by the horse fetal gonad. Horse fetal gonadal tissue was incubated with 3 beta-hydroxy-5,7-pregnadien-20-one and 5,7-cholestadien-3 beta-ol and it was shown that both substrates were converted to 3 beta-hydroxy-5,7-androstadien-17-one. These findings support the proposal that in this tissue there is a 5,7-diene pathway producing 3 beta-hydroxy-5,7-androstadien-17-one, the putative precursor of equilin in the placenta.
Transformation of cultured equine fibroblasts with a bovine papillomavirus. Fetal equine fibroblasts exposed to bovine papillomavirus became transformed by the criteria of morphological alterations and the acquisition of an increased life span, although they failed to grow in soft agar. Papillomavirus genome persisted in the transformed fibroblasts and was apparently not integrated with the cellular genome. These findings support the notion that bovine papillomaviruses are involved in the production of equine sarcoids.
Maximal anaerobic (lactic) capacity and power of the horse. Blood lactate concentrations were determined in 16 horses (three Thoroughbreds, seven Standardbreds and six polo ponies) before and 5 mins after they galloped over distances of 200, 300 and 400 m at maximal speed. The highest net lactate concentration (delta Lamax) of 14 to 15 mmol/litre was attained by the polo ponies and the highest speed by the Thoroughbreds. The maximal rate of lactate production (delta Låmax) was about 35 mmol/litre X min for the polo ponies and 20 to 25 mmol/litre X min for the Standardbreds and the Thoroughbreds. Values for delta Lamax and delta Låmax were similar to ...
Variant specific opsonization of Trypanosoma evansi measured by luminol-dependent chemiluminescence. Using luminol-dependent chemiluminescence (LCL), the specificity of antibodies to variable antigen type (VAT)-populations of Trypanosoma evansi was studied in four infected ponies. Trypanosomes of each wave of parasitemia were isolated and multiplied in irradiated mice. Their opsonization by serum collected during the infection was investigated with LCL and results for isolated VAT-populations are shown in the paper. Antibodies specific to each VAT-population were first found three days after the maximum of a parasitemic wave. There was no cross reactivity between different VAT-populations. LC...
Inhibition of lipases by proteins. A kinetic study with dicaprin monolayers. We report further investigations on protein inhibition of pancreatic and microbial lipases carried out with the monolayer technique. When beta-lactoglobulin A, melittin, serum albumin, myoglobin, and a protein inhibiting lipase from soybean were preincubated with a dicaprin film at a surface pressure of 35 dynes/cm, no activity was detected with horse pancreatic or Rhizopus delemar lipases. By contrast, Rhizopus arrhizus and Geotrichum candidum lipase activities were not impaired under the same conditions. Experiments using mixed lipid-protein film transfer clearly show that the inhibition of ...
Changes in the skeletal muscles volume in horses with growth. The area of the largest transverse section and the number of muscle fibres in a unit sectional area (1 mm2) were examined in 8 trunk and 12 extremity muscles of young and adult 16 light horses and 8 ponies. It was found that the area of the largest transverse section was enlarged and the number of muscle fibres in a unit area was decreased, with the advance in age. This result suggests that the development of muscle volume does not depend on the increase in the number of fibres, but depends on the hypertrophy of each muscle fibre.
Assignment of foal paternity when a mare is bred to two stallions. Accuracy of assigning foal paternity to the second serving stallion for foals whose dams had been bred to two stallions within an interval of 1 to 45 days was investigated using breeding dates from 108 equine paternity cases solved by blood typing. One hundred two of the foals were sired by the second stallion but six foals (5.5%) were excluded as being by the second sires. Thus, breeding dates are not reliable as a sole source of information to assign equine paternity accurately.
Equine congenital defects. In a 13-year survey of equine congenital defects that resulted in death or required euthanasia in central Kentucky, necropsies were performed on 608 deformed fetuses or newborn foals. The following congenital anomalies were observed: contracted foal syndrome (33.2%), miscellaneous limb contraction (20%), multiple defects (5.3%), microphthalmia (4.6%), craniofacial malformations (4.3%), cleft palate (4.0%), heart defects (3.5%), umbilical defects (3.5%), and hydrocephalus (3.0%). Eleven less frequently occurring anomalies constituted the balance of the congenital defects in fetuses and newborn ...
Surgical management of perineal lacerations and rectovestibular fistulae in the mare: a retrospective study of 47 cases. The case records of 47 mares with third-degree perineal lacerations or rectovestibular fistulae were examined to evaluate their fertility following surgical repair. Of 32 mares bred, 24 became pregnant, suggesting that surgical repair is indicated in any mare with sufficient genetic potential. Perineal trauma after surgical repair was recorded in 3 of 20 mares at subsequent parturition.
A new field strain of equine abortion virus (equine herpesvirus-1) among Kentucky horses. From restriction endonuclease characterization of the DNA of 317 isolates of equine abortion virus (equine herpesvirus-1; EHV-1) from 176 epizootically unrelated outbreaks of equine virus abortion occurring over 24 years in Kentucky, an epizootic pattern and variation of the virus have emerged. Two electropherotypes of EHV-1 (1P and 1B) accounted for greater than 90% of the nonvaccine-related abortion isolates examined. From 1960 to 1981, EHV-1 1P was the predominant isolate circulating in the central Kentucky area and the cause of greater than 80% of EHV-1-related abortions. In 1981, the occu...
Influence of several perturbants on the rate of autoxidation of horse heart ferrocytochrome c. The effect of several different types of perturbants and pH on the rate of autoxidation of horse heart ferrocytochrome c was investigated. The kinetic behavior is unique to each perturbant used. Rates of autoxidation followed first-order kinetics over the time span (0-180 min) studied. The Cl- and Br- anions exhibit an initial increase in the rate of autoxidation up to 100 mM, followed by a decrease in kinetics at 500 mM anion concentration. The ClO4- anion exhibits only an increase in the rate of autoxidation with increasing ionic strength, where as, propylurea, a hydrophobic perturbant, is n...
Blood group and protein polymorphism gene frequencies for seven breeds of horses in the United States. Gene frequencies at 20 blood group and protein polymorphism loci (A, C, D, K, P, Q, U, Al, Tf, Pi, Xk, Es, Gc, PGD, CA, Cat, PGM, AP, Hb and PHI) are given for seven horse breeds in the United States (Thoroughbred, Arabian, Standardbred, Morgan, Quarter Horse, Paso Fino and Peruvian Paso). These data are used to calculate that the battery of tests is at least 96% effective for recognizing incorrect paternity in these breeds. In addition to paternity testing, these tests can be applied to studies of breed relationships.
Spontaneous craniofacial malformations and central nervous system defects in an aborted equine foetus. Developmental defects are rarely reported in the horse. Severe craniofacial and central nervous system defects in an equine foetus are described and their possible causation and pathogenesis are suggested.
