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.
Swierstra EE, Gebauer MR, Pickett BW.The cycle of the seminiferous epithelium of the stallion was
divided into eight stages, using as criteria the presence of meiotic divi-
sions, shape of the spermatid nuclei and location of spermatids with
elongated nuclei in the tubule. The mean frequencies ofstages 1 to 8 were
16\m=.\9, 14\m=.\9, 3\m=.\2, 15\m=.\8, 7\m=.\4, 13\m=.\5, 12\m=.\6 and 15\m=.\7%, respectively. The
duration of one cycle of the seminiferous epithelium was 12\m=.\2 days
(S.E.\m=+-\0\m=.\1) as determined by injecting a single dose of 700 \g=m\Ciof
[3H]thymidine into each spermatic artery of six stallions and rem...
Ek N.Levels of the immunoglobulins IgG and IgG(T) in serum in Norwegian horses of the breeds “Døle” and “Fjord” were determined by the quantitative radial immunodiffusion test. No significant differences were apparent between the 2 Norwegian breeds. The immunoglobulin levels were approximately in the same range as previously reported for Shetland ponies. Immunoglobulins could not be detected in the newborn foal. As early as 24 hrs. after birth the mean immunoglobulin level was within the adult range. After a drop during the first month of life, the immunoglobulins increased. IgG(T) rose mo...
Hoy TG, Harrison PM, Shabbir M, Macara IG.The rate of release of iron to 1,10-phenanthroline from ferritin fractions of different iron contents has been studied. The experimental results could be interpreted by a simple hypothetical model of the shape of the hydrous ferric oxide micelle at different iron contents, and reasonable correlation obtained between the rate of release and the calculated micelle surface areas. Initial rates of release did not correlate significantly with protein concentration.
Bize I, Driscoll DM.Preservation of stallion sperm forward motility was studied using a video recording system in semen diluted with media of different ionic strength and sodium content. After 8 hr of incubation at room temperature, semen diluted in a low ionic strength media containing sucrose displayed 65 +/- 9% motility with 68 +/- 3% of the motile sperm showing forward motility (diameter of head trajectory greater than or equal to 80 microns). In contrast, sperm populations diluted and incubated with a normal ionic strength media containing sodium had 56 +/- 7% motile sperm of which only 36 +/- 7% displayed f...
Kingma SE, Thibault ME, Betteridge KJ, Schlaf M, Gartley CJ, Chenier TS.Poor survival of cryopreservation by equine expanded blastocysts may involve low penetration of the embryonic capsule by cryoprotective agents (CPAs). This study characterized the permeation and accumulation rates of the CPAs ethylene glycol (EG) and glycerol (GLY) across isolated capsule in vitro, using a dual-chambered Valia-Chien permeation apparatus. Pieces of Days 14 to 18 ± 1 capsules separated media in the "donor" chamber containing either 1.5 M EG (n = 6), 0.74 M EG (n = 5), 0.87 M GLY (n = 7), or 0.15 M NaCl (saline, SAL) (n = 6), from the "recipient" chamber. Concentrations of CPA, ...
Thomas PG, Ball BA.To facilitate the study of interactions between equine spermatozoa and homologous oviduct epithelial cells, we developed an assay to count labelled spermatozoa bound to oviduct epithelial cell (OEC) monolayers and used the assay to compare the binding ability of spermatozoa from different stallions. Washed spermatozoa from three stallions were incubated with the fluorochrome Hoechst 33342 (5 micrograms/ml) for 1 min. Spermatozoa were then layered over confluent monolayers of oviduct epithelial cells in 2 cm2 culture wells. Coculture treatments comprised five concentrations of spermatozoa (10(5...
Neis A, Kremer FS, Pinto LS, Leon PMM.The prolactin hormone is involved in several biological functions, although its main role resides on reproduction. As it interferes on fertility changes, studies focused on human health have established a linkage of this hormone to fertility losses. Regarding animal research, there is still a lack of information about the structure of prolactin. In case of horse breeding, prolactin has a particular influence; once there is an individualization of these animals and equines are known for presenting several reproductive disorders. As there is no molecular structure available for the prolactin hor...
Escribano BM, Castejon FM, Santisteban R, Aguera EI, Rubio MD.A study has been made of the variations experienced by the hemogram and blood volume indices in 16 Andalusian horses after carrying out an exercise test of increasing intensity consisting of 3 sequences of 1000 m each, before and after being subjected to a daily exercise programme for two months. Samples were taken by external jugular vein puncture: while at rest, within the first minute of finalizing each exercise stage and at 10 and 15 minutes of recovery. Both the red blood cells and the hematocrit value showed a significant decrease in their mean values after two months training; conversel...
The Journal of heredityFebruary 20, 2014
Volume 105, Issue 3 429-435 doi: 10.1093/jhered/esu005
Coizet B, Nicoloso L, Marletta D, Tamiozzo-Calligarich A, Pagnacco G, Crepaldi P.The dietary demand of the modern horse relies on high-cereal feeding and limited forage compared with natural grazing conditions, predisposing the horse to several important diseases. Salivary and pancreatic alpha-amylases (coded by AMY1 and AMY2 genes, respectively) play a crucial role in carbohydrate digestion in nonruminants, but little is known about these 2 genes in the horse. Aim of this work has been to distinguish genomic sequences of horse AMY1 and AMY2 genes and to analyze any polymorphisms in breeds historically characterized by marked differences in nutritional management. A single...
Hall SJ.An objective and accountable method is needed for deducing the number of registered animals in a breed from registration data. By following the principle that individual breeders register sufficient young females to be certain of having enough replacements for their current breeding stock, the ratios were calculated of the number of adult females in a breed to the number of female registrations, in a given year. Number of breeds considered were 8 cattle, 16 sheep, 8 pigs, 1 goat and 2 equines, all in the United Kingdom or Ireland. This yielded multipliers (4.4 for cattle, 3.3 for sheep, 3.1 fo...
Dowsett KF, Pattie WA.Semen was collected from 222 stallions of 13 breed or colour types in southern Queensland and northern New South Wales. A total of 648 collection attempts were made, using an artificial vagina, during 4 consecutive breeding seasons (1974/5 to 1977/8). Modifications were made to the techniques used by previous workers because collections were made at commercial studs using minimal animal restraint. Of all collection attempts, 621 (96%) were successful, while at least one semen sample was collected from each of 216 stallions (97%). There were no significant relationships between stallion collect...
Pizzi GLBL, Valente ALS, Rechsteiner SMEF, Bruhn FRP, Cruz LAX, Silva PM, Barbosa AA, Ribeiro PF, Martins CF.This study evaluated the influence of the Body Condition Score (BCS) and subcutaneous fat thickness on the tissue composition of the digital cushion in horses. Sixty mixed breeds of Criollo horses (21 males and 39 females) were sent for slaughter. All animals were submitted to BCS analysis, through visual antemortem evaluation, and then ultrasound evaluation to estimate the subcutaneous fat thickness. Macroscopic analyses of the thoracic and a pelvic limb (weight, volume, and density of the hooves and digital cushions) were performed. In addition, measurements of the area of internal structure...
Brück I, Hyland JH.The contributions of 2 biochemical pathways to the total metabolism of glucose (the Embden-Meyerhof pathway [EMP] and the pentose phosphate pathway [PPP]), were assessed for equine embryos recovered on Day 4.5, 7.5 and 11.5 post ovulation. At all developmental stages studied, glucose was metabolized through both pathways. Through the EMP, the amounts of glucose metabolized per nl embryo volume per hour were 4.0, 9.9 and 3.1 pmol, whereas via the PPP, amounts were 0.9, 1.7 and 0.07 pmol for Day-4.5, -7.5 and -11.5 embryos, respectively. The ratio of EMP:PPP with age was 9.7 for Day -4.5 embryos...
Meier H.The biography of Colonel Hermann Schwyter, equine surgeon of the Swiss Army from 1928 to 1937, and the history of training of farriers in Switzerland since the 18th century are presented. Hermann Schwyters dissertation examined the changes of equine hoof confirmation as a result of standing and gait in approximately 2,000 horses and numerous anatomical specimens. He defines the foot placement, describes possible variations, their causes and effects. Significant is also his study of the compression pathology in horses and mules. His recommendations are still valid today. The present article ref...
Brinkmeyer-Langford C, Raudsepp T, Gustafson-Seabury A, Chowdhary BP.A total of 207 BAC clones containing 155 loci were isolated and arranged into a map of linearly ordered overlapping clones over the proximal part of horse chromosome 21 (ECA21), which corresponds to the proximal half of the short arm of human chromosome 19 (HSA19p) and part of HSA5. The clones form two contigs - each corresponding to the respective human chromosomes - that are estimated to be separated by a gap of approximately 200 kb. Of the 155 markers present in the two contigs, 141 (33 genes and 108 STS) were generated and mapped in this study. The BACs provide a 4-5x coverage of the regio...
van Niekerk FE, van Niekerk CH.The effect of total protein intake and protein quality on the serum concentrations of certain reproductive hormones during the anovulatory, transitional and ovulatory periods were studied in 36 Anglo-Arab mares. High-quality protein stimulated FSH and LH production during the late transitional period. Serum progestagen and melatonin concentrations were unaffected by the quality of protein nutrition during the anovulatory period. Mares receiving high-quality protein exhibited a 10-14-day cyclical pattern of FSH release approximately 4-6 weeks earlier than the mares fed the lower-quality protein...
van Bömmel-Wegmann S, Gehlen H, Barton AK, Büttner K, Zentek J, Paßlack N.Little is known about the animal- and diet-related factors that could interfere with the plasma zinc (Zn) concentrations of equines. Additionally, the adequacy of plasma to reflect changes in the Zn intake is unclear. In the first part of this study, the plasma Zn concentrations of hospitalized horses and ponies ( = 538) were measured and evaluated for the impact of the age, sex, horse type, and internal diseases of the animals. In the second part, the effects of increasing dietary Zn chloride hydroxide and Zn methionine supplementations were assessed on the plasma and mane hair Zn concentrati...
de Vries PJ, Zandee AR.As part of the veterinary surveillance of horse breeding management, the veterinarian is increasingly often requested to predict ovulation and to give a breeding or insemination advice accordingly. The result of a teasing procedure is indispensable for this advice. A suggestion is made for the quantification of oestrus signs. Oestrus symptoms are classified into four categories. In addition, various factors are mentioned, which affect the result of a teasing procedure.
Pick M.Intensive strain of racing-horses during training and race is not an end in itself but should be understood from the social task to create exceptionally efficient horses. This roughness in sports obliges the responsible associations to issue rigorous regulations for the protection of horses. In this paper, some physical and psychical disorders of racing-horses are described. Improved keeping conditions as well as performance-adapted training methods will help to avoid defects. The aids being used during training and races are critically investigated on their effects according to the regulation...
Klug E, Brinkhoff D, Flüge A, Scherbarth R, Essich G, Kienzler M.Practical experiences of the phantom method for collection of genital secretions from stallions are reported. Taking a phantom used in the Richard-Götze-Haus Tierärztliche Hochschule Hannover as a prototype two further models slightly modified have been constructed, baring a flat hollow in the right side of the caudal phantom body for manual inserting of the Artificial Vagina. These three models fulfill four important conditions for routine use: (1) sufficient sexual attractivity for the stallions; 80-85% successful collections of presecretions out of a total of 1050 using the dummy and 70% ...
Bennet ED, Hayes ME, Friend L, Parkin TDH.Endurance competitions over distances of 80-160 km are required by Fédération Equestre Internationale (FEI) rules to be divided into a number of stages between three and six. These stages are also known as "loops". Veterinary inspections, designed to ensure horse welfare, are conducted at the end of each loop, with details recorded on a separate "vet card" for each horse. Objective: To identify risk factors recorded on vet cards that were associated with elimination at subsequent loops. Methods: Retrospective cohort study. Methods: Data relating to 3213 horse starts worldwide in internation...
Douthit TL, Bormann JM, Kouba JM.The objective of this study was to retrospectively analyze demographic variables and academic preparation of students to determine how these factors relate to student performance in ASI 521 Horse Science, an upper-level course offered in the Department of Animal Sciences and Industry (ASI) at Kansas State University (KSU). Data were collected for 264 students enrolled in the course from 2008 to 2010. Students who took the course in 2008 received greater final percentages than those who took the course in subsequent years (P = 0.0016). Females tended to receive greater percentages than males (P...
Schweizer C, Ramseyer A, Gerber V, Christen G, Burger D, Wohlfender FD.Racetrack injuries are of welfare concern and the prevention of injuries is an important goal in many racing jurisdictions. Over the years this has led to more detailed recording of clinical events on racecourses. However, risk factor analyses of clinical events at race meetings have not been previously reported for Switzerland. Objective: To identify discipline-specific factors that influence the occurrence of clinical events during race meetings with the ultimate aim of improving the monitoring and safety of racetracks in Switzerland and optimising racehorse welfare. Methods: Retrospective s...
Bowman SG, Marshall JF, Blikslager AT.To determine demographic characteristics of horses donated to the North Carolina State University Equine Health Center (EHC) between 1996 and 2008. Methods: Retrospective cohort study. Methods: 122 horses donated to the EHC between January 1996 and December 2008, and 246 horses offered for donation to the EHC between January 2007 and December 2008. Methods: Telephone and medical records were examined. Data were collected in 5 categories: age, sex, breed, reason for donation, and use prior to donation. Results: From January 1996 through December 2008, 122 horses were donated to the EHC (median,...
Torres-Boggino F, Sato K, Oka A, Kanno Y, Hochi S, Oguri N, Braun J.Seminal characteristics, fertility and the response to semen preservation (liquid storage and cryopreservation) were evaluated in 4 Draft stallions (Percheron 2, Breton 2). Seminal characteristics (gel-free volume, sperm concentration, sperm morphology, percentage of motile spermatozoa) were assessed in 5 ejaculates from each of the 4 stallions. The fertility of the stallions was calculated retrospectively as the accumulated pregnancy rate over 3 breeding seasons. Five ejaculates from each of the stallions were subjected to liquid storage at 5 degrees C. The percentage of motile spermatozoa (P...
Mouncey R, Arango-Sabogal JC, de Mestre AM, Foote AK, Verheyen KL.Enhanced understanding of reasons for, and timings of, mortality in Thoroughbreds prior to entering race training is warranted to provide insight into this population's health status. The aims of this study were to describe pathologies diagnosed at post-mortem (PM) examination in Thoroughbreds aged from birth to 18 months and investigate associations between age and pathology. Reports from a pathology laboratory in Newmarket, UK, were used to identify eligible cases examined between January 2006 and December 2020. Reported pathologies were extracted and categorised where appropriate. Comorbidi...
Ferrer MS, Canisso IF, Podico G, Ellerbrock RE, Hurley DJ, Palomares R.Different stallions exhibit a high level of variation in the ability of their sperm to survive cryopreservation. A large fraction of stallions show poor post-thaw sperm motility, and their semen is not suitable for commercial freezing. In this study, we hypothesized that the presence of sperm-bound antisperm antibodies (ASAs) was associated with poor cryosurvival of stallion sperm. Our objective was to assess the level of ASA binding to stallion sperm, and determine if it was associated with good or poor sperm cryosurvival. In Experiment 1, cooled shipped semen from 27 stallions was frozen usi...
Lee J, Shin D, Kim H.Thoroughbred horses have been bred exclusively for racing in England for a long time. Additionally, because horse racing is a global sport, a healthy leisure activity for ordinary citizens, and a high-value business, systematic racehorse breeding at the population level is a requirement for continuous industrial development. Therefore, we established genomic evaluation system (using prize money as horse racing traits) to produce spirited, agile, and strong racing horse population. Methods: We used phenotypic data from 25,061 Thoroughbred horses (all registered individuals in Korea) that compet...
Braun J, Torres-Boggino F, Hochi S, Oguri N.The objective of this experiment was to examine the effect of seminal plasma on motion characteristics of epididymal and ejaculated equine spermatozoa during storage at 5 degrees C. Epididymal spermatozoa were flushed with either seminal plasma or a skim milk-glucose extender. Ejaculated spermatozoa were collected with extender added 10 minutes after semen collection and addition of extender during ejaculation by placing 50 ml extender in the collection bottle. Semen samples were centrifuged and resuspended with a skim milk-glucose extender containing seminal plasma (0, 5 and 25%; v/v), prepar...
Luiz MA, Senna D, Padilha FGF, Nogueira WA, Fonseca AB, de Mello MFV, Ferreira AMR.The aim of this study was to perform linear measurements and assess morphometric indices of equines of the Pantanal race of different ages in the municipality of Poconé-Mato Grosso. Fifty-seven clinically healthy male and female horses between 1 and 19 years of age were selected and divided into groups by sex: 41 animals males and 17 animals femeles, and age groups: group 1 (nine animals up to 12 months of age), group 2 (eight animals from 12 to 24 months), group 3 (15 animals from 24 to 48 months), and group 4 (27 animals older than 48 months). With the aid of a hypometer, the following...
Frazer GS, Bucci DM.The aims of this project were to document the protein profile of equine seminal plasma and determine the variability between stallions in the relative composition of proteins in the ejaculate. A single ejaculate was obtained from 14 stallions of varying breed and age. The gel fraction was removed by an in-line filter. The semen was centrifuged and the supernatant seminal plasma aspirated without disturbing the sperm pellet. The seminal plasma was recentrifuged and stored in cryovials at -70 degrees C. Samples were thawed, recentrifuged, assayed for protein concentration (BCA protein assay), di...
Rieger D, Bruyas JF, Lagneaux D, Bézard J, Palmer E.The decrease in embryo viability caused by cryopreservation may be due, in part, to metabolic disturbances. To determine the effect of cryopreservation on metabolism, Day -6.5 horse embryos were either frozen and thawed using glycerol as the cryoprotectant, given only the glycerol treatment or washed an equal number of times in phosphate buffered saline (PBS). Before and after treatment, individual embryos were incubated with L-[14C(U)]-glutamine, to measure Krebs cycle activity, and D-[5-3H]-glucose, to measure Embden-Meyerhof pathway activity. Before treatment, glucose metabolism ranged from...
Parlevliet JM.The studies described in this thesis investigated the factors that can affect the fertility of stallions. The introduction describes the male gamete and the processes that occur during maturation of sperm and fertilization. Methods to evaluate the quality of sperm and ova are then discussed. Fertility can be expressed in various ways and is also affected by many factors such as the stallion, the mare and management factors. The fertility of stallions is usually assessed a good year after they have served mares, because then the number of foals is known. However, it would be preferable to be ab...
