Horse breeds represent the diverse genetic and phenotypic variations found within the species Equus ferus caballus. These breeds are categorized based on characteristics such as size, conformation, coat color, and temperament, which have been selectively bred over centuries to fulfill specific roles and functions. Common classifications of horse breeds include light horses, draft horses, and ponies, each serving different purposes ranging from riding and racing to work and companionship. This page aggregates peer-reviewed research studies and scholarly articles that explore the genetics, history, and functional attributes of various horse breeds, as well as their impact on equine management and breeding practices.
Mason TA, Bourke JM.The careers of many Thoroughbred racehorses
are marred or terminated prematurely by unsoundness which develop when racing as two year
olds. Common problems are sore-shins, carpitis,
splints, sesamoiditis, sesamoid fractures and
sprained joints and tendons. There appears to
be no recorded information on the incidence of
these conditions or of overall wastage in two year old Thoroughbreds but the results of personal
observations and communications with practising
veterinarians suggest that the incidence of unsoundnesses and relate these to skeletal maturity
Australia. This is probably d...
Platt H.Abortion in the Thoroughbred mare has been studied from the standpoint of its statistical incidence and the factors that predispose to its occurrence. The pathological findings in a series of aborted foetuses submitted for autopsy are described. Some aspects of the aetiology of abortion in the mare are discussed.
Gospodarowicz D.A highly purified preparation of PMSG has been obtained from fresh serum and from a commercial preparation. Carbohydrate and amino acid compositions have been determined. The carbohydrate content of PMSG is 46.7% and the molecule is rich in Sialic Acid (13.5%). The apparent molecular weight of PMSG has been determined by SDS polyacrylamide gel electrophoresis. A molecular weight of 53,000 has been found for the unreduced and unalkylated molecule. After reduction and alkylation, the molecular weight fell to 23,000. From these values it has been concluded that PMSG is an oligomeric molecule comp...
Milne FJ.FOR MANY YEARS, concern has been expressed at the wastage of young Thoroughbreds at the racetrack. This concern even manifested itself in the publication of a book (1) which referred to the prevailing practice of prematurely start-ing the racing career of the Thoroughbred long before it had attained sufficient maturity to engage in stiff, damaging competition. This is not a fault of the Thoroughbred industry alone, because in certain parts of the U.S.A., Quarter Horses less than two years of age are already racing. We could swing to the opposite extreme, of course, to the pleasure horse world ...
Sales FA, Ferreira-Silva JC, Vieira JI, Chaves MS, Caldas EL, Filho JP, Freitas VJ, Oliveira MA.Addition of extenders to thawed semen could improve fertility. Objective: To determine the efficiency of extenders to increase viability of thawed semen, measured by sperm parameters in vitro and pregnancy rates after artificial insemination (AI). Methods: Sperm motility and acrosin activity were measured during a thermoresistance test (TRT). Results: Progressive motility decreased (P<0.05) after 30 min in thawing semen treated with saline solution (SS) and only after 60 min with Tyrode's solution (TS) or freezing diluent (FD). The total motility decreased (P<0.05) after 60 min in thawed semen...
Schaefer RJ, Cullen J, Manfredi J, McCue M.A gene's response to an environment is tightly bound to the underlying genetic variation present in an individual's genome and varies greatly depending on the tissue it is being expressed in. Gene co-expression networks provide a mechanism to understand and interpret the collective transcriptional responses of genes. Here, we use the Camoco co-expression network framework to characterize the transcriptional landscape of adipose and gluteal muscle tissue in 83 domestic horses (Equus caballus) representing 5 different breeds. In each tissue, gene expression profiles, capturing transcriptional re...
Meier H.Both a mandate of the Bernese Government (1705) and statements in the Georgica Helvetica of 1706 prove that Swiss horse breeding was lucrative and of good quality at that time. However, the political turmoil at the transition from the 18th to 19th century and excessive sales to France and Italy led to a severe drop in quantity as well in quality. The exhibition of horses in Aarau in 1865 showed a wretched state of the material. In the same year, Rudolf Zangger wrote a guide for the discussion of horse breeding in Switzerland. In the following year (1866), Johann Jakob Rychner published a repor...
Klug E, Sieme H.The equine virus arteritis (EVA) consistently epidemically varying throughout the different breeds of the horse breeding countries is up to now only of lower significance by means of the typical clinical manifestation as well as an abortion causing factor. The susceptibility of the sexual mature stallions against the equine arteritis virus (EAV) causes different infection response which may lead to some restrictions in their use in natural breeding especially in the artificial insemination. In a certain not precisely predictable part of the stallion population EAV infection will cause a transi...
Johnson L.A new approach to quantification of Sertoli cells is described. The number of Sertoli cells per testis was calculated from the number of spermatids per testis, the number of spermatids per Sertoli cell apex, and the correction for the lifespan of spermatids enumerated per testis. To evaluate this method under different physiological conditions, testes from 28 adult (4-20-year) stallions obtained in the nonbreeding season (December-January) and from 28 adult stallions in the breeding season (June-July) were compared. Number of Sertoli cells per gram parenchyma was similar between seasons. Howev...
Krumrych W, Skórzewski R, Malinowski E.The aim of this study was to determine the effect of duration and temperature of sample storage on whole blood chemiluminescence measurement results. Venous blood from 18 clinically healthy Polish half-bred horses aged 4 to 11 years were used in the study. Luminol dependent chemiluminescence (CL) was used to measure neutrophil oxygen metabolism in whole blood. Blood samples were examined for spontaneous CL and stimulated by a surface receptor stimulus as well as extra-receptor stimulus. The assay was performed in two parallel experimental sets with samples stored at 4 and 22 °C, respectively....
Pilarczyk B, Tomza-Marciniak A, Stankiewicz T, Błaszczyk B, Gaczarzewicz D, Smugała M, Udała J, Tylkowska A, Kuba J, Cieśla A.The aim of this study was to determine serum selenium concentrations in Polish Konik horses residing in the Odra Delta Nature Park (Poland) and to evaluate the activity of glutathione peroxidase and Se content in testes of this horse breed. In over 95% of cases, serum Se concentration was below the optimal range, and none of the horses examined was deficient in this trace element. The lack of Se deficiency in the animals examined suggests however, that the Polish Konik horses have a natural ability to the optimal use of nutrients available in their life area. Testicular content of Se and GSHPx...
Wessel MT, Ball BA.Osmotic stress is an important component of the damage to spermatozoa during cryopreservation. Osmotic injury, due to hyperosmolar freezing extenders, changes in relative solute concentration in the extra cellular medium during freezing and differences in the relative permeabilities of penetrating cryoprotectants, such as glycerol, and water occur when cryopreserved spermatozoa are diluted into isosmotic media or when spermatozoa are placed in the female reproductive tract. The purpose of the study reported here was to evaluate the effect of step-wise dilution for the removal of the permeating...
Lykkjen S, Stenbakk LK, Holmøy IH.Laminitis is a systemic condition resulting in debilitating pain and structural changes within the feet, and hence has major welfare implications. Causes include endocrine and systemic inflammatory conditions. Ponies are frequently affected, and observations in the field suggest that occurrence of laminitis is also common in Norwegian breeds. The aim of this study was to estimate the prevalence and risk factors for laminitis within the Norwegian pony breed Nordlandshest/Lyngshest. Results: The study was a cross-sectional study based on questionnaires sent to members of the Norwegian Nordlands...
Whalen LR, Wheeler DW, LeCouteur RA, Yovich JV, Boggie LC, Grandy JL, Kainer RA.Maximal conduction velocities of compound action potentials evoked by stimuli of 2 times threshold in the caudal cutaneous sural (CCSN) and medial cutaneous antebrachial (MCAN) nerves were determined by averaging potentials evoked and recorded through percutaneous needle electrodes. Mean maximal conduction velocities of compound action potentials were: CCSN = 61.3 +/- 2.0 meters/second (m/s) and MCAN = 56.4 +/- 2.8 m/s. To confirm accuracy of our percutaneous recordings, compound action potentials were recorded through bipolar chlorided silver electrodes from the exposed surfaces of fascicles ...
Morris LH.The generally recommended minimum number of spermatozoa required for conventional artificial insemination in the mare is in excess of 200 x 10(6) progressively motile spermatozoa. Recent developments in different insemination techniques such as deep uterine, hysteroscopic and oviductal insemination, which have been designed to use significantly fewer spermatozoa, are reviewed in this paper. A number of studies have demonstrated that ultrasound guided deep uterine insemination of 5 x 10(6) fresh spermatozoa can produce satisfactory pregnancy rates. The use of hysteroscopic insemination enables ...
Rozhkov IuI, Okhapkin SK, Vorob'ev EG, Bezenko SP, Galimov IR.A stabilizing selection which is made in cattle according to phenotypic characters affects simultaneously a genetic character--the level of individual heterozygosity++. As a result animals with mean (modal) level of heterozygosity++ have the least probability of elimination. Similarly, the driving selection in pigs and horses leads to a change in both phenotypic characters and genetic character, the level of individual heterozygosity++. In this case the most heterozygous animals have the least probability of elimination.
Herzog B, Lindner A, Sommer H.To compare the career profiles of thoroughbred racehorses in Germany in different decades all horses which raced for the last time in the years 1966/67, 1976/77 and 1986/87 were selected from the annual report of the German Thoroughbred Racing Association. The number of racing horses increased within decades while the percentage of the horses which raced for the last time was equal in all years. It amounted yearly to about 30%. Most of the horses finished racing at three and four years of age. In 1966, 1967, 1976 and 1977 more than 50% of the horses began their career at the age of two years, ...
Clarke PN.Application of nursing theory in daily life by applying elements of Parse's paradigm allowed for a more expansive view of the dressage experience by focusing on the paradox of visible-invisible in the unique rhythmic-patterns of the horse-rider team. The study of classical nursing theory has diminished in a similar pattern as classical dressage. The importance of studying the classics in any field is emphasized along with concerns about the future of nursing and healthcare.
Lewczuk D, Metera-Zarzycka E.Many horse breeds in the world are reserved as genetic resources; however, their characteristics seem to be insufficiently clarified, especially in terms of horse performance. Two jumping ability evaluation methods have been used to compare different types of performance breeds and on this basis their applicability for precision phenotyping has been determined. Methods: Jumping data of 186 young Polish Warmblood stallions (27 with an endangered status) bred for sport and multipurpose use was collected during their performance tests organised under identical environmental conditions following t...
Huricha , Kawai M, Ninomiya S.In this study, we investigated suckling behavior and the distance between a foal and its mare as indicators of foal growth in Hokkaido native horses (HKD) during the first 40 days of life. Direct observations were made of 22 mare and foal pairs from two consecutive days 1 and 2, 5 and 6, 10 and 11, 20 and 21, 30 and 31, and 40 and 41 after birth by focal animal sampling for 3 h per day. Suckling behavior was continuously recorded, along with the terminator. The distance between the foal and its mare was determined using the instantaneous sampling method (1 min), and the percentage was calc...
Nunes DB, Zorzatto JR, Costa e Silva EV, Zúccari CE.Five experiments tested the efficiency of a simple, low-cost system (CP) for cooling and storing equine semen at 2.0 degrees C for 24 h and 48 h. Pantaneiro stallions of known fertility were used. Semen quality was evaluated for progressive motility (PM), plasma membrane integrity (PMI), and pregnancy rate. Experiment 1 showed that PM and PMI were similar between CP and the control (Equitainer) in cooled semen. In Experiment 2, the influence was evaluated of combinations (four treatments) of two volumes (50/100 ml) and two sperm concentrations (500/750x10(6)) on sperm quality of semen cooled a...
Schembri MA, Major DA, Suttie JJ, Maxwell WM, Evans G.To investigate cryopreservation-induced capacitation-like changes in equine spermatozoa frozen in three different media using chlortetracycline (CTC) fluorescence staining analysis. Methods: Semen collected from three stallions was diluted in one of three centrifugation media and, after centrifugation and removal of supernatant, extended in corresponding freezing media containing additional egg yolk, glycerol, lactose and Equex paste. The semen was frozen in 5 mL straws and the spermatozoa assessed for motility and membrane quality after thawing. Results: Following centrifugation, spermatozoa ...
Coutinho da Silva MA, Seidel GE, Squires EL, Graham JK, Carnevale EM.Objectives were to determine the effects of extracellular Ca(2+) and milk proteins on intracellular Ca(2+) concentrations in stallion sperm; and to determine the effects of single caseins on sperm binding to the zona pellucida (ZP). In Experiment I, sperm were incubated in media containing 2 or 4mM Ca(2+) and intracellular Ca(2+) concentration was determined after ionomycin treatment and long-term incubation (3h). Extracellular Ca(2+) concentrations (2 compared with 4mM) did not affect baseline intracellular Ca(2+) concentration of sperm. However, incubating sperm in a medium containing 4 comp...
Rath D, Leiding C, Klug E, Krebs HC.Ejaculates were collected at 3-day intervals before, during and after a washing procedure with chlorhexidine (2%). Semen motility and pathology were determined before and after deep-freezing. Blood samples were taken before and within 1 h after washing procedures and then extracted in ether. This was followed by HPL chromatography. Chlorhexidine concentrations in blood and seminal plasma were distinctly higher in the treated stallions than in control groups. Concentrations in the control groups were below the detection limit of the column. Significant correlations between decreasing semen qual...
Kniazev SP, Nikitin SV.The study of the association between the coat-color variants and the blood-group system D antigens in the populations of two related trotter breeds (Orlov Trotter and Russian Trotter) showed the presence of three associations between these characters in the Orlov Trotter breed. In the populations of Russian trotters, these associations were not detected. Possible reasons for the formation and maintenance of these associations and the role of the selection for coat color in the differentiation of breeds by the frequencies of some system D antigens are discussed.
Forsyth IA, Rossdale PD, Thomas CR.Small samples of mammary secretion were collected from eight Thoroughbred mares during the last week of pregnancy, at foaling and after 1 week of lactation. Specific assays showed the presence of both lactose and triglyceride in all samples before birth and progressive increases in their concentrations in colostrum and in milk. Levels of 6-0 g lactose/100 ml and 1-8 g triglyceride/100 ml were present in milk at 7 to 9 days post partum. The secretory capacity of the udder is thus normally established well before parturition in the mare. Attempts to demonstrate the occurrence of a placental lact...
Smale K, Butler PJ.A new oxygen equilibrium curve is defined for the Thoroughbred horse under standard conditions of 37 degrees C, pH = 7.4 and PCO2 = 5.33 kPa. The "standard" P50 for the Thoroughbred is, at 2.83 +/- 0.04 (SE of mean) kPa, significantly lower than that found for the Hanoverian horse (3.17 +/- 0.03 kPa) by Clerbaux et al. (Can. J. Vet. Res. 50: 188-192, 1986), and lower than other values for horses in the literature. Using data from Butler et al. (J. Exp. Biol. 179: 159-180, 1993), curves were also constructed, in vitro, under simulated conditions of intense exercise to examine the individual eff...
Webb PD, Steven DH.The adrenal cortex from twelve fetal foals (gestational ages from 61 to 300 days) was examined by light and electron microscopy. Adrenal glands from three newborn foals were also examined by light microscopy. Between 61 and 100 days of gestation the adrenal cortex became organised into two distinct regions, the zona glomerulosa and zona fasciculata, which grew steadily in thickness until the 300th day. Between 300 days and birth there was a dramatic increase in the width of the zona fasciculata. From 200 days a narrow band of compact cells marked the cortico-medullary border. Though these cell...
Harris PA.An outbreak of muscle stiffness and poor performance among 59 thoroughbreds at a Newmarket flat racing yard was investigated between the beginning of May and the end of June 1986. Over a third of the horses showed signs of muscular stiffness, and 38 had, at one or more of the sampling times, creatine kinase (CK) activities above 200 iu/litre and, or, aspartate aminotransferase (AST) activities above 300 iu/litre when they were sampled six to eight hours after exercise. The following season, at a similar time and stage of training, only four of 39 horses sampled had CK activities between 200 an...
Papin J, Stuhtmann G, Martinsson G, Sieme H, Lundeheim N, Ntallaris T, Morrell JM.Removal of seminal plasma facilitates stallion sperm survival during storage, but washing may damage sperm chromatin. Therefore, sperm quality was compared in samples following single-layer centrifugation (SLC) or sperm washing and controls (extension only) in two extenders, INRA82 and INRA96. Ejaculates from six stallions were split among six treatments: SLC, sperm washing, and controls, in INRA82 and INRA96. Sperm motility and acrosome status were evaluated at 0, 24, 48, 72 and 96 hours; morphology at 0, 24, 48, 72 hours and chromatin integrity at 0 and 96 hours, with storage at 6°C. Sperm ...
Herbach N, Nagel L, Zwick T, Hermanns W.Pancreatic neuroendocrine tumors of glucagon-producing cells are extremely rare in domestic animals. In this report, we describe for the first time, to our knowledge, the incidental finding of multiple glucagon-producing neuroendocrine tumors of the pancreas of a horse. The animal was euthanized due to severe local infection after tooth extraction. On postmortem examination, multiple white nodules of up to 4 cm in diameter were observed in the pancreas. Histologically, pancreatic nodules had the appearance of neuroendocrine neoplasms with positive immunoreactivity for glucagon, synaptophysin, ...
Chen J, Wang H, Li J, Liu S, Li B, Sun Y, Wang H, Manglai D.To date, the origins, domestication, and genetic structure of Chinese Mongolian horses (CMH) are poorly understood. Furthermore, there have been sparse reports on the genetic differences between CMH and Thoroughbred. In order to determine their genetic structure, understand their genetic relationships, and explore their domestication processes, we performed an extensive survey of creatine kinase (muscle isoenzyme; variations among six populations of indigenous CMH, cultivated Sanhe horses, and imported Thoroughbred. Twenty-three single-nucleotide polymorphisms were found among the 343 horse s...
Köhne M, Kirch F, Tönissen A, Martinsson G, Rabe U, Sieme H, Schuberth HJ.To improve accuracy in evaluating stallion ejaculates, an antibody-based, flow cytometric assay for the detection and identification of leukocyte subpopulations (CD4-, CD8-, CD21-, CD172a-positive cells) in stallion semen (n = 12) was established. For establishment of the assay, native semen was supplemented with blood leukocytes (control: 20% leukocytes, 80% sperm cells) and analysed by flow cytometry. Adding antioxidants (ascorbic acid and butylated hydroxytoluol) to semen immediately after collection inhibited rapid death of lymphoid cells in sperm leukocyte mixtures. In control set-ups...
Leeb T.The growing knowledge on physiology, cell biology and biochemistry of the reproductive organs has provided many insights into molecular mechanisms that are required for successful reproduction. Research directed at the investigation of reproduction physiology in domestic animals was hampered in the past by a lack of species-specific genomic information. The genome sequences of dog, cattle and horse have become publicly available in 2005, 2006 and 2007 respectively. Although the gene content of mammalian genomes is generally very similar, genes involved in reproduction tend to be less conserved...
