The population dynamics of horses refers to the study of changes in horse populations over time, influenced by factors such as birth rates, death rates, immigration, and emigration. These dynamics are shaped by environmental conditions, resource availability, predation, and human intervention. Understanding population dynamics is essential for managing wild horse populations and ensuring sustainable practices in breeding and conservation efforts. This page compiles peer-reviewed research studies and scholarly articles that explore the factors affecting horse population dynamics, including genetic diversity, habitat utilization, and the impact of management strategies on population stability and growth.
Kumar S, Kumar R, Gupta AK, Yadav SC, Goyal SK, Khurana SK, Singh RK.Equine piroplasmosis is a tick-transmitted protozoan disease caused by Theileria equi and/or Babesia caballi. In the present study, we expressed a 53kDa protein from the truncated EMA-2 gene of T. equi (Indian strain) and developed EMA-2ELISA using this expressed protein. This ELISA is able to detect T. equi-specific antibodies in experimentally infected animals as early as 9 days post-infection. The assay developed was validated with the OIE recommended competitive ELISA (cELISA) on 120 serum samples and significant agreement (kappa=0.93) was observed between results of both the ELISAs which ...
van Beest FM, Uzal A, Vander Wal E, Laforge MP, Contasti AL, Colville D, McLoughlin PD.Density is a fundamental driver of many ecological processes including habitat selection. Theory on density-dependent habitat selection predicts that animals should be distributed relative to profitability of habitat, resulting in reduced specialization in selection (i.e. generalization) as density increases and competition intensifies. Despite mounting empirical support for density-dependent habitat selection using isodars to describe coarse-grained (interhabitat) animal movements, we know little of how density affects fine-grained resource selection of animals within habitats [e.g. using res...
Marjamäki PH, Contasti AL, Coulson TN, McLoughlin PD.Movement away from an area or social group in response to increasing density (density-dependent dispersal) is known for most species; why it evolves is fundamental to our understanding of ecology and evolution. However, we have yet to fully appreciate how individuals of varying conditions (e.g., age and sex) might differently consider effects of density (quorum) when deciding to disperse or not, and scale dependence in their sense of quorum. We tracked movements of all individuals of a naturalized population of feral horses (Equus ferus caballus; Sable Island National Park Reserve, Nova Scotia...
Liu G, Xu CQ, Cao Q, Zimmermann W, Songer M, Zhao SS, Li K, Hu DF.Przewalski's horses have been imported from the western zoos to China since 1985. Yet the genetic diversity in China's populations has not been studied, thus lacking of such knowledge inevitably affects this population's management. The aim of this study was to assess genetic diversity in Chinese population of Przewalski's horses via mitochondrial DNA (mtDNA) control region and pedigree analysis. Methods: Two captive and one reintroduced populations were examined based on mitochondrial DNA control region variation via fecal sampling from 2010 to 2012, together with pedigree analysis. Results: ...
Velie BD, Stewart BD, Lam K, Wade CM, Hamilton NA.Research in Thoroughbred racehorses is often specific to horses from a given racing population or region. In order to investigate trends in racehorse careers across populations accurately, population-specific benchmarks for performance outcomes must be established. Objective: To provide summary statistics for performance outcomes for Thoroughbreds racing in Hong Kong between 2000 and 2010 and to document and provide evidence on the current differences in racing careers across sexes and regions of origin for horses racing in Hong Kong. Methods: Performance data on the population of Thoroughbred...
Janova E, Futas J, Klumplerova M, Putnova L, Vrtkova I, Vyskocil M, Frolkova P, Horin P.The Old Kladruber horses arose in the 17th century as a breed used for ceremonial purposes. Currently, grey and black coat colour varieties exist as two sub-populations with different recent breeding history. As the population underwent historical bottlenecks and intensive inbreeding, loss of genetic variation is considered as the major threat. Therefore, genetic diversity in neutral and non-neutral molecular markers was examined in the current nucleus population. Fifty microsatellites, 13 single nucleotide polymorphisms (SNPs) in immunity-related genes, three mutations in coat colour genes an...
Pirault P, Danvy S, Verrier E, Leroy G.Since horse breeds constitute populations submitted to variable and multiple outcrossing events, we analyzed the genetic structure and gene flows considering horses raised in France. We used genealogical data, with a reference population of 547,620 horses born in France between 2002 and 2011, grouped according to 55 breed origins. On average, individuals had 6.3 equivalent generations known. Considering different population levels, fixation index decreased from an overall species FIT of 1.37%, to an average [Formula: see text] of -0.07% when considering the 55 origins, showing that most horse ...
Winton CL, Hegarty MJ, McMahon R, Slavov GT, McEwan NR, Davies-Morel MC, Morgan CM, Powell W, Nash DM.The conservation of unique populations of animals is critical in order to preserve valuable genetic diversity and, where populations are free-living, maintain their irreplaceable influence upon habitat ecology. An accurate assessment of genetic diversity and structure within and between populations is crucial in order to design and implement conservation strategies in natural and domesticated species. Moreover, where it is possible to identify relic populations that are related to a structured breed an ideal opportunity presents itself to model processes that reveal historical factors that hav...
The Journal of heredityFebruary 28, 2013
Volume 104, Issue 3 386-398 doi: 10.1093/jhered/est003
Khanshour A, Conant E, Juras R, Cothran EG.The Arabian horse ignites imagination throughout the world. Populations of this breed exist in many countries, and recent genetic work has examined the diversity and ancestry of a few of these populations in isolation. Here, we explore 7 different populations of Arabians represented by 682 horses. Three of these are Middle Eastern populations from near the historical origin of the breed, including Syrian, Persian, and Saudi Arabian. The remaining Western populations are found in Europe (the Shagya Arabian and Polish Arabian) and in America (American Arabian). Analysis of genetic structure was ...
Tetens J, Widmann P, Kühn C, Thaller G.A genome-wide association scan for loci affecting withers height was conducted in 782 German Warmblood stallions, which were genotyped using the Illumina EquineSNP50 Bead Chip. A principal components approach was applied to correct for population structure. The analysis revealed a single major QTL on ECA3 explaining ~18 per cent of the phenotypic variance, which is in concordance with recent reports from other horse populations. The LCORL/NCAPG locus represents a strong candidate gene for this QTL. This locus is among a small number that have consistently been identified to influence human hei...
Petersen JL, Mickelson JR, Cothran EG, Andersson LS, Axelsson J, Bailey E, Bannasch D, Binns MM, Borges AS, Brama P, da Câmara Machado A, Distl O....Horses were domesticated from the Eurasian steppes 5,000-6,000 years ago. Since then, the use of horses for transportation, warfare, and agriculture, as well as selection for desired traits and fitness, has resulted in diverse populations distributed across the world, many of which have become or are in the process of becoming formally organized into closed, breeding populations (breeds). This report describes the use of a genome-wide set of autosomal SNPs and 814 horses from 36 breeds to provide the first detailed description of equine breed diversity. F(ST) calculations, parsimony, and dista...
Ransom JI, Hobbs NT, Bruemmer J.Abiotic inputs such as photoperiod and temperature can regulate reproductive cyclicity in many species. When humans perturb this process by intervening in reproductive cycles, the ecological consequences may be profound. Trophic mismatches between birth pulse and resources in wildlife species may cascade toward decreased survival and threaten the viability of small populations. We followed feral horses (Equus caballus) in three populations for a longitudinal study of the transient immunocontraceptive porcine zona pellucida (PZP), and found that repeated vaccinations extended the duration of in...
Petersen JL, Mickelson JR, Rendahl AK, Valberg SJ, Andersson LS, Axelsson J, Bailey E, Bannasch D, Binns MM, Borges AS, Brama P, da Câmara Machado A....Intense selective pressures applied over short evolutionary time have resulted in homogeneity within, but substantial variation among, horse breeds. Utilizing this population structure, 744 individuals from 33 breeds, and a 54,000 SNP genotyping array, breed-specific targets of selection were identified using an F(ST)-based statistic calculated in 500-kb windows across the genome. A 5.5-Mb region of ECA18, in which the myostatin (MSTN) gene was centered, contained the highest signature of selection in both the Paint and Quarter Horse. Gene sequencing and histological analysis of gluteal muscle...
McGree JM, Noble G, Schneiders F, Dunstan AJ, McKinney AR, Boston R, Sillence M.We describe the population pharmacokinetics of an acepromazine (ACP) metabolite (2-(1-hydroxyethyl)promazine) (HEPS) in horses for the estimation of likely detection times in plasma and urine. ACP (30 mg) was administered to 12 horses, and blood and urine samples were taken at frequent intervals for chemical analysis. A bayesian hierarchical model was fitted to describe concentration-time data and cumulative urine amounts for HEPS. The metabolite HEPS was modelled separately from the parent ACP as the half-life of the parent was considerably less than that of the metabolite. The clearance (Cl/...
Leroy G, Mary-Huard T, Verrier E, Danvy S, Charvolin E, Danchin-Burge C.Effective population sizes of 140 populations (including 60 dog breeds, 40 sheep breeds, 20 cattle breeds and 20 horse breeds) were computed using pedigree information and six different computation methods. Simple demographical information (number of breeding males and females), variance of progeny size, or evolution of identity by descent probabilities based on coancestry or inbreeding were used as well as identity by descent rate between two successive generations or individual identity by descent rate. Results: Depending on breed and method, effective population sizes ranged from 15 to 133 ...
Solé M, Valera M, Gómez MD, Cervantes I, Fernández J.Limiting the inbreeding rate (∆F) while maximizing genetic gain for any trait of economic interest is especially important in small populations of local breeds, like the Menorca Horse. In this breed, dressage performance is important for the profitability of the breed and should be accounted in the selection criterion. The aim of this study was to assess if a breeding programme aiming at improved dressage performance is feasible in such a small breed. To perform the analysis, animals that were currently available for breeding (between 3 and 20 years) were used. Selection was based on the es...
Hughes J, Allen RC, Baguelin M, Hampson K, Baillie GJ, Elton D, Newton JR, Kellam P, Wood JL, Holmes EC, Murcia PR.The ability of influenza A viruses (IAVs) to cross species barriers and evade host immunity is a major public health concern. Studies on the phylodynamics of IAVs across different scales - from the individual to the population - are essential for devising effective measures to predict, prevent or contain influenza emergence. Understanding how IAVs spread and evolve during outbreaks is critical for the management of epidemics. Reconstructing the transmission network during a single outbreak by sampling viral genetic data in time and space can generate insights about these processes. Here, we ob...
Tydén E, Morrison DA, Engström A, Nielsen MK, Eydal M, Höglund J.The large roundworm of horses, Parascaris equorum is considered ubiquitous in breeding operations, and is regarded as a most important helminth pathogen of foals. Over the past decade, this parasite has been reported increasingly resistant to anthelmintic drugs worldwide. This paper reports analysis of the population genetic structure of P. equorum. Adult parasites (n=194) collected from Sweden, Norway, Iceland, Germany, Brazil and the USA were investigated by amplified restriction fragment length polymorphism (AFLP) analysis. The genetic variation was low (Hj=0.12-0.4), for the global populat...
Contasti AL, Tissier EJ, Johnstone JF, McLoughlin PD.Fine-scale spatial variation in genetic relatedness and inbreeding occur across continuous distributions of several populations of vertebrates; however, the basis of observed variation is often left untested. Here we test the hypothesis that prior observations of spatial patterns in genetics for an island population of feral horses (Sable Island, Canada) were the result of spatial variation in population dynamics, itself based in spatial heterogeneity in underlying habitat quality. In order to assess how genetic and population structuring related to habitat, we used hierarchical cluster analys...
Hernández-Jover M, Roche S, Ward MP.Vector-borne diseases can have substantial impacts on human and animal health, including major epidemics. West Nile virus (WNV) is of particular international importance due to its recent emergence and impact in the Western Hemisphere. Despite the presence of a sub-type of WNV (Kunjin virus, KUN) in Australia, a potential ecological niche could be occupied by an exotic strain of WNV of the North American type. This study assesses the probability an exotic strain of WNV enters Australia via an infected mosquito in an aircraft from the United States (U.S.) landing at Sydney airport, the probabil...
Velie BD, Knight PK, Thomson PC, Wade CM, Hamilton NA.Studies of Thoroughbred racing populations have provided evidence of a positive effect on racing careers for horses that commence racing as 2-year-olds. Currently, research investigating the presence of this effect in the Australian Thoroughbred racing population is limited. Objective: To investigate the association between age at first start and career length in the Australian Thoroughbred population and estimate the risk of racing retirement for horses racing in Australia based on age at first start, career earnings, number of starts as a 2-year-old and distance raced. Methods: Data were col...
Hampson BA, de Laat MA, Mills PC, Pollitt CC.To better understand the morphology of, and the effect of different travel patterns and varying substrate environments on, the feral horse foot to better manage the feet of domestic horses. Methods: The left forefeet of 20 adult feral horses from each of five geographically separated populations in Australia (n = 100) were investigated. Populations were selected on the basis of substrate hardness under foot and the amount of travel typical for the population. Feet were radiographed and photographed and 40 morphometric measurements of each foot were obtained. Results: Of the 40 parameters, 37 d...
Sitzenstock F, Rathke I, Ytournel F, Simianer H.A reference horse-breeding programme with 13500 foals each year was modelled with ZPLAN+. This new software for the optimization of the structures in breeding programmes is based on ZPLAN. In two scenarios, the implementation of a rigorous selection of mares was implemented. In scenario I, the mare performance test was the point of selection, while in scenario II, further information on 20 competitions in two more years is available. These selected mares were used for embryo transfer (ET), partly in combination with multiple ovulation (MOET). The selection intensity and the number of foals out...
Xu LX, Yang SL, Lin RY, Yang HB, Li AP, Wan QS.China is one of the principal origins of ponies in the world. We made a comprehensive analysis of genetic diversity and population structure of Chinese ponies based on 174 animals of five indigenous Chinese pony breeds from five provinces using 13 microsatellite markers. One hundred and forty-four alleles were detected; the mean number of effective alleles among the pony breeds ranged from 5.38 (Guizhou) to 6.78 (Sichuan); the expected heterozygosity ranged from 0.82 (Guizhou) to 0.85 (Debao, Sichuan). Although abundant genetic variation was found, the genetic differentiation was low between t...
Velie BD, Wade CM, Hamilton NA.Research investigating trends in racehorse careers require a benchmark for accurate comparison. Currently little whole population data exists for horses racing in Australia. Objective: To determine the range and variation in career length and number of career starts for horses racing in Australia. To document and provide evidence regarding the current differences between the sexes for career length and careers starts. Methods: Racing data were collected for Thoroughbreds over a 10-year period. Career length, number of career starts and spells per year were evaluated. Statistical analyses were ...
Desgorces FD, Berthelot G, Charmantier A, Tafflet M, Schaal K, Jarne P, Toussaint JF.Running speed in animals depends on both genetic and environmental conditions. Maximal speeds were here analysed in horses, dogs and humans using data sets on the 10 best performers covering more than a century of races. This includes a variety of distances in humans (200-1500 m). Speed has been progressing fast in the three species, and this has been followed by a plateau. Based on a Gompertz model, the current best performances reach 97.4% of maximal velocity in greyhounds to 100.3 in humans. Further analysis based on a subset of individuals and using an 'animal model' shows that running spe...
Rosanowski SM, Cogger N, Rogers CW, Benschop J, Stevenson MA.We conducted a cross-sectional survey to determine the demographic characteristics of non-commercial horses in New Zealand. A sampling frame of properties with non-commercial horses was derived from the national farms database, AgriBase™. Horse properties were stratified by property size and a generalised random-tessellated stratified (GRTS) sampling strategy was used to select properties (n=2912) to take part in the survey. The GRTS sampling design allowed for the selection of properties that were spatially balanced relative to the distribution of horse properties throughout the country. Th...
Moridi M, Masoudi AA, Vaez Torshizi R, Hill EW.To understand the origin and genetic diversity of Iranian native horses, mitochondrial DNA (mtDNA) D-loop sequences were generated for 95 horses from five breeds sampled in eight geographical locations in Iran. Sequence analysis of a 247-bp segment revealed a total of 27 haplotypes with 38 polymorphic sites. Twelve of 19 mtDNA haplogroups were identified in the samples. The most common haplotypes were found within haplogroup X2. Within-population haplotype and nucleotide diversities of the five breeds ranged from 0.838 ± 0.056 to 0.974 ± 0.022 and 0.011 ± 0.002 to 0.021 ± 0.001 res...
Głażewska I, Prusak B, Gralak B.The goal of this study was to demonstrate the usefulness of pedigree data in studies of mitochondrial DNA diversity in dogs and horses. Pedigree information allows for precisely choosing animals with distinct haplotypes for analysis, makes it possible to find rare haplotypes present exclusively in single individuals and helps to evaluate haplotype frequencies at the present and in the past. Estimating founder contributions to gene pools enables evaluating the parts of gene pools observed with the help of mtDNA analysis. An important aspect is also the financial benefits: using pedigree data, r...
Warmuth V, Manica A, Eriksson A, Barker G, Bower M.Many events in the history of eastern Eurasia, including the process of domestication itself, the initial spread of domestic horses and subsequent movements, are believed to have affected the genetic structure of domestic horse populations in this area. We investigated levels of within- and between-population genetic diversity in 'non-breed horses' (working horses sampled in remote areas) from 17 locations in Asia and parts of Eastern Europe, using 26 autosomal microsatellite loci. Non-breed horses have not been subject to the same intensity of artificial selection and closed breeding as have ...
Novak BJ, Brand S, Phelan R, Plichta S, Ryder OA, Wiese RJ.Over 40 years ago, scientists imagined ways cloning could aid conservation of threatened taxa. The cloning of Dolly the sheep from adult somatic cells in 1996 was the breakthrough that finally enabled the conservation potential of the technology. Until the 2020s, conservation cloning research efforts yielded no management applications, leading many to believe cloning is not yet an effective conservation tool. In strong contrast, domestic taxa are cloned routinely for scientific and commercial purposes. In this review, we sought to understand the reasons for these divergent trends. We scoured p...
Yordanov G, Palova N, Mehandjyiski I, Hristov P.From a historical perspective, horse breeding in Bulgaria has been very well developed since the time of the Thracians (early Bronze Age c. 3000 BCE). Archaeological discoveries from this era present us with an extremely rich type diversity, including wild and local primitive horses, the prototype of heavy draft horses, and fine riding horses.The objective of this study was to investigate the genetic structure of unexamined populations of three closely related horse breeds - the Danubian Nonius Hungarian Nonius and Serbian Nonius horses. A 608?bp long fragment of the mtDNA D-loop region was am...
Gurgul A, Jasielczuk I, Szmatoła T, Sawicki S, Semik-Gurgul E, Długosz B, Bugno-Poniewierska M.Nanopore sequencing is a third-generation biopolymer sequencing technique that relies on monitoring the changes in an electrical current that occur as nucleic acids are passed through a protein nanopore. Increasing quality of reads generated by nanopore sequencing systems encourages their application in genome-wide polymorphism detection and genotyping. In this study, we employed nanopore sequencing to identify genome-wide polymorphisms in the horse genome. To reduce the size and complexity of genome fragments for sequencing in a simple and cost-efficient manner, we amplified random DNA fragme...
Kaminski M, de Andres Cara DF.Genetic variants at eight blood loci were analysed, disclosing in Andalusian breed six rare markers: variants J of transferrin, H of esterase, D and S of Xk, M and W of prealbumin. Two of these, TfJ and PrM appear as characteristic markers of Andalusian breed. Allelic frequencies showed minor differences between Spanish (300 horses) and Lusitanian (100 horses) populations. Comparison was established with historically related breeds, Thoroughbreds or Connemara, and with Arab horses because of a presumed relationship. No visible similarities in genetic profiles were found with two former breeds,...
Barrett E, Arkins S.Few studies are available concerning prevalences of abnormalities in the Thoroughbred horse population. Objective: Determine the prevalence of commonly observed abnormalities in a National Hunt Thoroughbred population using results of pre-purchase examinations conducted at Thoroughbred sales venues. Methods: Retrospective cross-sectional study. Methods: Veterinary pre-purchase examination certificates for 13,603 3- and 4-year-old Thoroughbred National Hunt horses from Tattersalls Ireland, Goffs Ireland and Doncaster Bloodstock Sales Ltd. (DBS) Sales were analysed. All conditions noted by the v...
Hesselholt M.By means of isoimmunizations and heteroimmunizations 10 equine blood typing reagents were isolated. The specific antibodies were complete agglutinins, which were used in the direct agglutination test in saline medium. The reagents were designated A2, C, D, E, G, H, I, K, Da1, and Da2 reagent. Da1 and Da2 are preliminary designations. The data obtained from blood typing of a family material and a population material of Icelandic horses showed that the occurrence of each blood type factor is controlled by a single, dominant gene. The family data tended to show that the blood factors under invest...
Hatami-Monazah H, Pandit RV.The group of Caspian ponies studied contained some animals with 65 chromosomes and others with 64 chromosomes. The morphology and G-banding pattern of the chromosomes resembled those of Equus caballus and E. przewalskii. The karyogram of animals with 65 chromosomes was identical to that of the cross between E. caballus and E. przewalskii. It is suggested that the Caspian pony is the product of natural hybridization between E. caballus and E. prezwalskii. Low reproductive effeciency of the Caspian pony is suggested as the cause of decline in the population of these animals.
Głażewska I, Prusak B, Gralak B.The goal of this study was to demonstrate the usefulness of pedigree data in studies of mitochondrial DNA diversity in dogs and horses. Pedigree information allows for precisely choosing animals with distinct haplotypes for analysis, makes it possible to find rare haplotypes present exclusively in single individuals and helps to evaluate haplotype frequencies at the present and in the past. Estimating founder contributions to gene pools enables evaluating the parts of gene pools observed with the help of mtDNA analysis. An important aspect is also the financial benefits: using pedigree data, r...
Gharahveysi S, Kashan NE, Gerami A, Torshizi RV.Arab horse is a popular pure breed in Iran and is registered by World Arabian Horse Organization (WAHO). There is no scientific study and research about this breed. In this research 13 conformation traits on a random sample of the Iranian Arab horses studied. The estimate of variance components estimated by Animal Model and Derivative Free Restricted Maximum Likelihood (DF-REML) approach and DF-REML software. Heritability of conformation traits is also evaluated. The range of estimated heritability were (0.050 +/- 0.008) neck length and (0.614 +/- 0.087) croup height. Results indicated that, c...
Berger J, Kock M, Cunningham C, Dodson N.Twenty-three (9 male, 14 female) wild horses (Equus caballus) in the Great Basin Desert were immobilized by ground techniques with succinylcholine chloride during 1,950 person-hr. Induction (means = 2.09 +/- 0.59 min) and recovery (means = 12.4 +/- 5.0 min) were rapid and most animals were returned in less than 10 min to original bands. Dosages ranged from 0.66-0.77 mg/kg body weight and neither abortions nor band changes in group membership resulted. However, a few concerted efforts up to 24 hr were needed to return some animals to original bands and three non-drug related mortalities occurre...
Wilson RT.Equines have been largely ignored in modern scientific literature on domestic animals, probably because they are not providers of meat and milk. Their contribution to the economy in the Sudan, however, is considerable and they are the principal means of transport both as baggage and as riding animals. They also play an important role in the supply of fuel and the distribution of domestic water in the larger villages and towns. Information on population structure is provided and descriptions, with particular reference to withers height and weight, are given of two types of donkey and of the hor...
Popot MA, Houghton E, Ginn A, Jones M, Teale P, Samuels T, Lassourd V, Dunnett N, Cowan DA, Bonnaire Y, Toutain PL.The purpose of the present report was to estimate the population parameters of cortisol concentrations in urine, an endogenous hormone used as a 'doping' agent and for which an international threshold (1.0 micrograms/ml) has been proposed. Two data bases (French and UK) corresponding to 112 and 142 samples, respectively were considered. Urine was collected under specific post competition conditions. Cortisol concentrations were obtained by validated methods (HPLC for the French samples, and GC-MS for UK samples). No difference was observed between the 2 data sets and statistical analyses were ...
Erickson JD, Lee DV, Bertram JE.The goal of this study was to identify changes in acetabular morphology associated with the use of horses by Native Americans. Previous studies reported "elongate" acetabula in horseback-riding members of the Omaha and Ponca populations. Such a difference in acetabular shape is a potentially useful osteological marker of habitual horseback riding. This report compares acetabula of adult males from two Native American Arikara populations known to have differed substantially in their use of horses. Population samples were from separate sites in South Dakota: Larson (nonriding) and Leavenworth (r...
Held F, Ekstrand C, Cvijovic M, Gabrielsson J, Jirstrand M.Cortisol is a steroid hormone relevant to immune function in horses and other species and shows a circadian rhythm. The glucocorticoid dexamethasone suppresses cortisol in horses. Pituitary pars intermedia dysfunction (PPID) is a disease in which the cortisol suppression mechanism through dexamethasone is challenged. Overnight dexamethasone suppression test (DST) protocols are used to test the functioning of this mechanism and to establish a diagnosis for PPID. However, existing DST protocols have been recognized to perform poorly in previous experimental studies, often indicating presence of ...
Khrabrova LA, Blohina NV, Bazaron BZ, Khamiruev TN.The Zabaikalskaya horse is an indigenous breed of horses from Siberia with diverse use. It is characterized by endurance and good adaptability to year-round herd maintenance in the harsh conditions of the Baikal steppes. To determine the genetic characteristics of the maternal lineage of the Zabaikalskaya horse breed based on mitochondrial DNA polymorphisms, we collected hair samples from 31 horses belonging to breeding farms in the Trans-Baikal Territory. Analysis of the 530 bp sequence of the mtDNA D-loop was performed using the maximum composite likelihood (MCL) model in combination with bo...
Velie BD, Stewart BD, Lam K, Wade CM, Hamilton NA.Research in Thoroughbred racehorses is often specific to horses from a given racing population or region. In order to investigate trends in racehorse careers across populations accurately, population-specific benchmarks for performance outcomes must be established. Objective: To provide summary statistics for performance outcomes for Thoroughbreds racing in Hong Kong between 2000 and 2010 and to document and provide evidence on the current differences in racing careers across sexes and regions of origin for horses racing in Hong Kong. Methods: Performance data on the population of Thoroughbred...
Machmoum M, Badaoui B, Petit D, Germot A, El Alaoui MA, Boujenane I, Piro M.Genetic diversity and phylogenetic relationships within the Arabian show horse populations are of particular interest to breeders worldwide. Using the complete mitochondrial DNA D-loop sequence (916 pb), this study aimed (i) to understand the genetic relationship between three populations, the Desert-Bred (DB), a subset of the Kingdom of Saudi Arabia (KSA), United Arab Emirates (UAE) and Bahrain (BAH), the Straight Egyptian (EG) and the Polish bloodline (PL), and (ii) to assess the accuracy of the traditional strain classification system based on maternal lines, as stated by the Bedouin cultur...
Esdaile E, Kallenberg A, Avila F, Bellone RR.Coat color is a trait of economic significance in horses. Variants in seven genes have been documented to cause white patterning in horses. Of the 34 variants that have been identified in KIT proto-oncogene, receptor tyrosine kinase (), 27 have only been reported in a single individual or family and thus not all are routinely offered for genetic testing. Therefore, to enable proper use of marker-assisted selection, determining breed specificity for these alleles is warranted. Screening 19 unregistered all-white Shetland ponies for 16 white patterning markers identified 14 individuals whose phe...
Yang F, Shao Q, Jiang Z.Using the Yellow-River-Source National Park (YRSNP) as a study site, an unmanned aerial vehicle (UAV) remote sensing and line transect method was used to investigate the number of wild herbivorous animals and livestock, including the kiang () and Tibetan gazelle (). A downscaling algorithm was used to generate the forage yield data in YRSNP based on a 30-m spatial resolution. On this basis, we estimated the forage-livestock balance, which included both wild animals and livestock, and analyzed the effects of functional zone planning in national parks on the forage-livestock balance in YRSNP. Th...
Martín-Jiménez T, Papich MG, Riviere JE.To develop and validate a population pharmacokinetic model for gentamicin in horses, using retrospective clinical data. Methods: 62 horses that had been treated IV with multiple doses of gentamicin at our veterinary teaching hospital between 1987 and 1996. Procedure-46 horses were assigned to the study group, and 16 to the validation group. Detailed history of dosage, sample collection times, and selected pathophysiologic variables were recorded for each patient. Samples were analyzed by use of a fluorescence polarization immunoassay method. Pharmacostatistical analysis was conducted, using co...
Smyth GB, Dagley K.To obtain information on the types of Australian horses, how they are kept and their activities. Methods: An invitation to participate in an opt-in, internet-based survey was sent to 7000 people who had registered an email address to receive information from the Australian Horse Industry Council Inc. Results: There were 3377 (48%) useable responses from owners of 26,548 horses. Most horses were kept on small properties (usually 2-8 ha) in paddocks in rural areas of Queensland, New South Wales and Victoria. Most horses were female or geldings and the most common of 54 different activities was...
De Stoppelaire GH, Gillespie TW, Brock JC, Tobin GA.The effects of grazing by feral horses on vegetation and dune topography at Assateague Island National Seashore were investigated using color-infrared imagery, lidar surveys, and field measurements. Five pairs of fenced and unfenced plots (300 m2) established in 1993 on sand flats and small dunes with similar elevation, topography, and vegetation cover were used for this study. Color-infrared imagery from 1998 and field measurements from 2001 indicated that there was a significant difference in vegetation cover between the fenced and unfenced plot-pairs over the study period. Fenced plots cont...
Reinemeyer CR, Smith SA, Gabel AA, Herd RP.Monthly variations in the magnitude of adult and larval cyathostome burdens were observed in 55 horses necropsied over a 15-month period in the northern USA. Peak numbers of adult cyathostomes occurred in late winter (March) and late summer (September). Larval cyathostomes demonstrated peak numbers from February to April and again in October, beginning one month earlier than the spring adult peak and one month after the autumn adult peak, respectively. The reproductive status of individual female Cyathostomum catinatum, Cyath coronatum, Cylicocyclus nassatus, Cylicostephanus goldi and Cylicost...
Farchati H, Merlin A, Saussac M, Dornier X, Dhollande M, Garon D, Tapprest J, Sala C.Accurate demographic knowledge of the equine population is needed to assess and model equine health events. France is one of the few European countries with an operational centralized database (SIRE) recording individual data on all declared equines living in France and on their owners and keepers. Our study aimed to assess SIRE database quality concerning the updating of information by equine owners and keepers with a view to its improvement and use in surveillance and research. Two online surveys were conducted with the participation of 6244 registered keepers and 13,869 owners. Results show...
Aberle K, Wrede J, Distl O.Gene contributions of foreign populations as well as coefficients of inbreeding and relationship were calculated in 1918 South German Coldblood horses registered in Bavaria in 2003. Based on nearly complete 8-generation-pedigrees (index of pedigree completeness: 76%) the mean coefficient of inbreeding was 23%. After considering missing pedigree data, the mean coefficient of inbreeding was 3%. The rates of inbreeding per generation in the current population amount to about 0.43% over the last eight generations and to about 0.15% in the forthcoming generation. In the total current population, th...
Hedrick PW, Miller PS.In recent years, more detailed genetic information has become available for individuals of endangered species in captive breeding programs. There have been suggestions that this information be used to identify rare alleles, particularly those at the MHC, that can be subsequently selected for captive breeding programs. First, we summarize the current information on the MHC relevant to conservation genetics, so that such a possible breeding program is seen in a proper perspective. For example, very few specific alleles at the MHC have been identified as selectively advantageous, even though ther...
Bailey E.The linkage group formed by the ELA and A blood group system in horses was studied in American Standardbred horses. The distance between the ELA locus and the A blood group locus was measured as 1.61 centimorgans, observing only the haplotypes contributed by the sires. Strong linkage disequilibrium was found in pacing Standardbred horses for ELA-W1 with Aa, ELA-W5 with Ab and ELA-W10 with Ab. Linkage disequilibrium was apparent at both the population and family level. Among trotting Standardbred horses, linkage disequilibrium was found for ELA-W1 with Aa and for ELA-W10 with Ab. It was not pos...
