Polish Horses Research Articles

Videodermoscopic analysis of the skin of purebred arabian horses and polish sport horses.

Videodermoscopy is a modern method of skin examination that significantly facilitates diagnosis. The purpose of the study was to determine and compare the characteristic features of the skin and its derivatives for Purebred Arabian and Polish Sports horses. The study was conducted in the winter of 2018/2019, with written consent obtained from the horses’ owners before examinations. The study involved 33 healthy horses not previously used for breeding, consisting of 21 purebred Arabian mares and twelve clinically healthy Polish Sports horses (SP). Videodermoscopic evaluations were performed of seven selected areas of the body: the forehead, mane, neck, chest, flank, rump, and tail. For the dermoscopic examination, an Italian Video-Dermascope 7 (Medici Medical SRL with 3 VIDIX 5Mpx camera and VX1 – Contact type cap Ø 3.5 cm) was used. The Olympus cellSens specialized software was used to analyze microscopic images and perform measurements. The comparison of hair thickness showed significant differences between the two groups: in most of the assessed body areas, the hair thickness was greater for the Arabian horses than for the Polish Sports horses. The hair thickness ranged from 52.70 μm on the chest to 87.45 μm on the mane in the Arabian horses and from 30.18 μm on the flank to 47.33 μm on the rump in the SP horses. In conclusion, the breed of the horse is an important factor that must be taken into consideration in both qualitative and quantitative evaluations of the skin and its derivatives.

Genetic Diversity and Maternal Phylogenetic Relationships among Populations and Strains of Arabian Show Horses.

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 culture. To that end, we collected 211 hair samples from stud farms renowned for breeding Arabian show horses from Nejd KSA, Bahrain, Egypt, Qatar, Morocco, UAE, and Poland. The phylogenetic and network analyses of the whole mitochondrial DNA D-loop sequence highlighted a great genetic diversity among the Arabian horse populations, in which about 75% of variance was assigned to populations and 25% to strains. The discriminant analysis of principal components illustrated a relative distinction between those populations. A clear subdivision between traditional strains was found in PL, in contrast to the situation of DB and EG populations. However, several Polish horse individuals could not be traced back to the Bedouin tribes by historical documentation and were shown to differ genetically from other studied Bedouin strains, hence motivating extended investigations.

GENETIC FEATURES OF TARPAN-LIKE HORSES OF THE POLISH PRIMITIVE (THE KONIK) BREED AND ESTABLISHMENT OF PHYLOGENETIC OF ANCIENT EGUIDS USING THE ISSR-PCR MARK

In the development of human society, the horse, compared to other domestic animals, played a central role. It became an integral part of the economic and intellectual development of ancient human settlements, a symbol of the transformation of subsequent great epochs. The last wild horse that survived in Ukraine until the end of the XIX century, according to many paleontologists, was the tarpan. However, this statement is still questioned. In the books and documents of old chroniclers and researchers we find descriptions of wild horses called tarpans, which could be found in the wooded areas of Poland, Lithuania and Prussia in the XVIII century. Emphasizing the forest existence of these horses, they received the Latin name Equii silvestris (forest horses). According to historical records, tarpans survived the longest in the wild in the vicinity of Bialowieza Forest, more or less until 1780, when they were finally caught and transferred to the Zoo of the Counts of Zamoyski (an influential Polish count) in the town of Zwierzyniec near the town of Bilhora in Lublin Voivodeship in eastern Poland. Around 1806, the zoo ceased to exist, and the horses were distributed to local peasants. Thus, we can assume that this is the last case of domestication of wild horses in Poland. The World Wide Fund for Nature (WWF) has launched a program to return the tarpan-like Polish horse to nature. Therefore, tarpan-like horses were brought to the Belarusian part of Belovezhskaya Pushcha and to the south-west of Latvia (1999) [11]. In 2009, with the consent of the Ministry of Environment of Ukraine and the Ministry of Nature Protection of Poland, horses of the descendants of the wild tarpan horse were brought to the territory of Yavoriv National Nature Park from Roztochansky National Park to preserve and reproduce the gene pool of these horses. However, the origin of the domestic horse and the history of most modern breeds remains unclear to this day. This is due to the fact that the bones of wild and domesticated horses are almost identical. The lack of diagnostic, anatomical and biometric criteria does not allow to determine the archaeozoological remains of the horse. To solve these problems molecular genetic analysis of horse DNA is used. With the use of molecular markers in research, there are new opportunities to study genetic diversity, as well as the definition of phylogenetic relationships at both intra- and interspecific levels. One of the types of genetic polymorphism research is ISSR-PCR - amplification of intermicrosatellite DNA fragments, the purpose of which is to conduct genetic monitoring in rocks in order to preserve the allelofund of a few rocks. (3) The aim of the work was to identify intraspecific genetic variability of tarpan-like horses of the Polish konik breed and to establish phylogenetic links between ancient equids (Pleistocene horse, real tarpan) using ISSR - fingerprinting. The material for the assessment of intraspecific and interspecific genetic variability and the establishment of phylogenetic relationships between modern horses and fossil remains of ancient horses were horses of the Polish konik breed (10 heads) of the Yavoriv National Nature Park of the Lviv Region. and fossil bones of horses of the Pleistocene period (about 10 thousand years BC), metacarpal bone (os. tarsicentral). The bone was found in Novgorod-Siversky, Chernihiv region during quarry construction work. The excavations were carried out by PI Borisovsky in 1935. A tooth found in the village of Tarpan was used to study a wild tarpan horse (4.5 thousand years BC). Skibnytsia, Trostyanets district, Vinnytsia region. Excavations were conducted in 1959 by VM Danylenko. The paleontological material that was studied was provided by the Kyiv National Museum of Natural History of the National Academy of Sciences of Ukraine, Department of Paleontology. It was found that the species-specific spectra of PCR products obtained by ISSR-PCR for species E.caballus are fragments of 380-400 np and 500-520 np. The breed-specific fragments of the DNA molecule inherent in horses of the Polish konik breed include spectra of amplification products with a size of 680-710 np. It was found that the genetic distances between the amplicons of ISSR-PCR markers of Polish horses and fossil remains of a Pleistocene horse were 0.0881 and between the remains of a real tarpan - 0.0845. The low value of the share of polymorphic loci (P) and the index of polymorphic information content (PIC) was revealed, which indicates a high degree of genetic consolidation of horses of the Polish konik breed and possible reproductive isolation of the population. It was established that the spectra of amplification products of horses of the Polish horse and fossil remains of Pleistocene horse and real tarpan by 97% on the universal scale of dimension of ISSR fragments in np belonged to "light" (A-35 - A-25) and "medium" -25 - A-13), which is a specific characteristic of E. caballus species.

Mitochondrial Whole D-Loop Variability in Polish Draft Horses of Sztumski Subtype.

Simple SummaryThe Polish draft horse (PDH) breed is a result of crossing local mares with imported cold-blooded stallions. In this study, we investigate the genetic composition of the PDH by analyzing whole mitochondrial d-loop variabilities and comparing these variabilities to previously demonstrated whole d-loop sequences of other cold-blooded breeds: Ardennais, Belgian, Breton, Clydesdale, Noriker, Norwegian Fjord, Percheron, and Suffolk. Our results show high nucleotide diversity among the PDH population and the existence of two main haplogroups with strong kinship to the Belgian breed.The Polish draft horse (PDH) breed is a result of crossing local mares with imported cold-blooded stallions, such as Belgians, Ardennes, Fjords, and others. A part of the broodmare stock investigated in this study was also imported from various countries, such as Denmark. In this study, we investigate the genetic composition of the PDH by analyzing the whole mitochondrial d-loop variability and comparing it to previously demonstrated whole d-loop sequences of other cold-blooded breeds: Ardennais, Belgian, Breton, Clydesdale, Noriker, Norwegian Fjord, Percheron, and Suffolk. Our results show high nucleotide diversity within the PDH population (π = 0.011), and the existence of two main haplogroups: one of relatively concise origin, with strong kinship to the Belgian breed, and the second showing close relation to the majority of other analyzed cold-blooded breeds. Some of the PDH maternal strains clustered separately, which can be a result of the influence of other unidentified breeds that served as a foundation stock for the present population. This present study explains the genetic relationship of the PDH to other cold-blooded breeds and indicates the high genetic diversity of the breed.

THE EFFECTIVENESS OF THE USE OF VARIOUS ISSR-MARKERS IN THE STUDY OF HORSES

The article presents the results of molecular genetic studies performed on samples of biological material from ancient horses (DNA was isolated from fossils of Pleistocene horse and tarpan) and three aboriginal breeds of modern horses (Polish horse, Hutsul breed, Arabian breed). The research was conducted in the laboratory of genetics IRGT. M.V.Zubets NAAS. Purpose of research. This work was carried out to compare the effectiveness of each of the ISSR-markers and then select the optimal combination in the study of polymorphism of the genetic structure of horses To study the DNA polymorphism of horses on ISSR markers, we used eight primers that are considered the most informative (AG)8CA, (AG)9C, (GA)6CC, (GA)9C, (AG)8CG, (GAG)6C, (ACC)6G, (CTC)6C.
 Research methods. DNA from the blood was isolated using a set of reagents "DNA sorb B". From fossil remains of horses, DNA was isolated by an optimized method using proteinase K and dithiothreitol. The PCR mixture contained: 1 μl of buffer for Tag polymerase, 1 μl of a mixture of triphosphates ("Amplisens", RF), 0.8 μl of the appropriate primer, 0.2 μl of DNA polymerase ("Fermentas", Lithuania), water for PCR 3 μl. Genomic DNA was added in an amount of 4 μl. The total volume of the DNA mixture was 10 μl. Amplification was performed on a programmed four-channel thermocycle "Tertsyk" ("DNA technology", Russia). The amplification program included primary denaturation (95°C, 2 min); 30 cycles of denaturation (95°C, 30 s), hybridization of primers (54–64°C, 30 s) and elongation (72°C, 1 min), finishing elongation (72°C, 5 min).
 To more accurately estimate the lengths of the detected amplification fragments, a universal scale was used, where the gradation of DNA fragments by molecular weights was used. Depending on the zone ("heavy", "medium" and "light" fragments), a certain step from 10 to 200 bp was used. As a result, 38 zones with a fixed interval were identified, which allow to accurately determine the molecular weight for amplification products of different lengths and standardize the results of this study.
 Obtained results and conclusions. In the study of the obtained spectra of amplification products, we found that the largest number of loci was obtained by using as primers the sequences (GA) 6CC and (GAG) 6C – 9 and 8 loci. At the same time, primers (AG) 8CA – 0.27, (AG) 9C – 0.21 and (ACC) 6G – 0.21 were the most polymorphic in terms of PIC. It should be noted that when using primer (GA) 6CC in the study of genetic polymorphism of horses was obtained a significant range of amplification products – 9 loci, with a polymorphism index of 0.16, which allows it to be used quite effectively for research. Using the sequence (AG) 8CG was characterized by the lowest PIC index and was 0.02. As a result, we found that the most effective for the detection of polymorphism in the PIC index in horses was the use of primers sequences (AG) 8CA, (AG) 9C, and (ACC) 6G. To obtain the largest range of amplification fragments in horses by ISSR-PCR, the most effective was the use of the sequence (GA) 6CC and (GAG) 6C.

Genetic Variability and Population Structure of Polish Konik Horse Maternal Lines Based on Microsatellite Markers

Simple SummaryThe aim of this study is to reveal the genetic variability and population structure of maternal lines of the Polish Konik—a native Polish horse breed of the primitive type included in the Polish conservation programme. The analysis was carried out on the basis of 17 microsatellite markers routinely used for parentage testing. The structural analysis indicated the likelihood of three genetic clusters (using the Structure and Structure Harvester software). F-statistics indicated a low level of inbreeding. All mean population coefficients were close to those obtained for representatives of male founder lines. The population seemed to be stable. However, due to a previous bottleneck event, breeding strategies should focus on avoiding inbreeding depression, preventing the decrease of genetic variability, and sustaining the active female lines.The aim of the conservation programme is to maintain the population size of endangered livestock breeds of less economic importance at a level that ensures the survival of the breed, the preservation of genetic diversity, and the preservation of as many pedigree lines as possible. The Polish Konik, a native Polish primitive-type horse breed and is one of the breeds included in such a programme in Poland. Presently, there are only 16 (of the 35 maternal lines known in 1962), some of which are endangered. We examined the genetic variability and structure of the Polish Konik maternal lines (176 individuals) on the basis of the pedigree data and 17 microsatellite markers (STRs) from parentage testing. The overall mean number of alleles was 7.647 (±0.411), the effective number of alleles was 3.935 (±0.271), the mean number of alleles for which the frequency was equal to or lower than 5% was 4.471 (±0.286), and the mean information index was 1.506 (±0.087). The structure of the population and admixture patterns were calculated with the Structure and Structure Harvester software. The structural analysis indicated three likely genetic clusters; as the most optimal K value was estimated as 3, with ∆K of 15.4188. The F-statistics results indicated a low level of inbreeding (average inbreeding coefficient FIT was 0.0188, coefficient of differentiation FST was 0.0304, and mean inbreeding index value FIS was −0.0119). Variability monitoring should be carried out in order to avoid inbreeding depression, while breeding strategies should be designed to prevent the decrease of genetic variability in the Polish horse breed and to sustain the active female lines.

Suitability of Pedigree Information and Genomic Methods for Analyzing Inbreeding of Polish Cold-Blooded Horses Covered by Conservation Programs.

Traditionally, pedigree-based relationship coefficients were used to manage inbreeding and control inbreeding depression that occurs within populations. The extensive incorporation of genomic data in livestock breeding creates the opportunity to develop and implement methods to manage populations at the genomic level. Consequently, the realized proportion of the genome that two individuals share can be more accurately estimated instead of using pedigree information to estimate the expected proportion of shared alleles. To make use of this improvement, in this study we evaluated the genomic inbreeding measures in the Polish conserved cold-blooded horse population and compared the data with the traditional measures of inbreeding. Additionally, an ancestry fractions/proportions from Admixture software were tested as an estimate of lineage (ancestry coefficient) used for horses qualifying for the conservation program. The highest correlation of pedigree-based (FPED) and genomic inbreeding estimates was found for FROH (runs of homozygosity-based F coefficient) and FUNI (F coefficient based on the correlation between uniting gametes). FROH correlation with FPED tended to increase as the number of generations registered as pedigree increased. While lineage and gene contributions (Q) from Admixture software correlated, they showed poor direct compliance; hence, Q-value cannot be recommended as the estimate of pedigree-based lineage. All these findings suggest that the methods of genomics should be considered as an alternative or support in the analysis of population structure in conservative breeding that can help control inbreeding in rare horse populations.

Genetic Variation in the Glycoprotein B Sequence of Equid Herpesvirus 5 among Horses of Various Breeds at Polish National Studs.

Equid herpesvirus 5 (EHV-5) is one of two γ-herpesviruses that commonly infect horses worldwide. The objective of the study was to estimate the genetic variability within EHV-5 viruses circulating among horses in Poland. Partial glycoprotein B (gB) sequences from 92 Polish horses from 13 studs throughout Poland were compared to each other and to three EHV-5 sequences from other countries. Despite the overall high level of conservation, considerable variability was observed around the putative furin cleavage site. Based on phylogenetic analysis, the viruses clustered within two major lineages (A and B), with further sub-clustering within group A. The clustering of EHV-5 sequences was independent of age or geographical origin of the sampled horses. Recombination was identified as one of the factors contributing to the genomic heterogeneity. Viruses from unweaned foals were more similar to viruses from other foals at the same stud than to viruses form their dams, suggesting the horizontal transfer and/or evolution of EHV-5 within individual hosts. Our data indicate that the gB sequence is not suitable for tracking the source of EHV-5 infection. Further research is needed to elucidate the importance of the sequence variability around the EHV-5 gB furin cleavage site on the biology of the virus.

Polish Horse-Riding School

The aim of the research was to recreate the processes determining the development of the concept of the Polish horse riding school. In the implementation of the previously adopted scheme, there were used methods in the field of historical and pedagogical science. As a result of the query, a lot of the material was obtained at the Central Military Archives in Warsaw and the Sports Museum in Olsztyn. It should be emphasized that the use of horses in the Republic of Poland has centuries of tradition. Yet in the 18th century, Polish horse riding school dominated in Europe. However, due to the subsequent partitions and the loss of independence, there were no conditions for further improvement of the equestrian art system. The next opportunity did not appear until 1918, when Poles created the foundation of statehood. Therefore, shortly thereafter, three military horse riding schools were established for the needs of the reviving weapon. They were dominated by the old classical-manege system, cultivated by senior officers from the former Armed Forces of Austria-Hungary. The new trends were initiated in the ranks of cavalry due to soldiers who had previously served in the army of the Russian partitioner. The results of the carried out research enabled to formulate the conclusion that allows to state that the clash of views among the officers resulted in the development of the principles of the Polish horse riding school. It was a combination of the Italian system and extensive experience of the former manege school. It was developed by horse riding instructors at the Cavalry Training Center in Grudziądz. Thanks to that, Polish horsemanship in the inter-war period was included in the world leaders.

Linkage disequilibrium, haplotype blocks and historical effective population size in Arabian horses and selected Polish native horse breeds

This study was conducted to investigate linkage disequilibrium (LD), historical effective population size (Ne) and haplotype block structures in genomes of highly selected Polish Arabian (AR; n=124) horses and conserved horse breeds derived from Polish native breeds, in particular, Malopolski (MLP; n=56), Sokolski (SOK; n=107), Sztumski (SZTUM; n=69), Hucul (HC; n=116) and Polish Konik (KN; n=99) horses, based on single nucleotide polymorphisms (SNPs) from the Neogen Equine Community BeadChip assay (Illumina, San Diego, CA). LD analysis was performed based on the pairwise r2 statistic of SNPs at a distance up to 5Mb. At a short distance, up to 100kb, the lower average r2 was observed in SOK (0.09) and SZTUM (0.10) breeds, representing draft horse type, and the highest average r2 was observed in AR (0.19) and MLP (0.17) breeds, representing light horse type. At a distance of 4-5Mb, the average values of r2 were 0.03 for HC and KN, 0.02 for AR and MLP and 0.01 for SOK and SZTUM. About 100 generations ago, effective population size (Ne) ranged from 518 (SOK) to 310 (AR) and five generations ago from 85 (SOK) to 40 (HC). A total of 6,162 (AR), 5,792 (MLP), 5,744 (HC), 5,429 (KN), 5,542 (SOK) and 4,848 (SZTUM) haplotype block structures, spanning 656.2Mb (AR), 439.4Mb (MLP), 381.2Mb (HC), 344.3 (KN), 206.7 (SOK) and 171.0Mb (SZTUM) of the genome were detected. Mean block lengths were estimated as 106.5±138kb, 75.9±120kb, 66.4±109kb, 63.4±109kb, 37.3±80kb and 35.3±81kb for AR, MLP, HC, KN, SOK and SZTUM, respectively. A visible similarity in the decay of LD across the genome, as well as in trends of historical Ne, were found for breeds representing the same horse type. Differences in the span of haplotype block structures were found between AR and Polish native horse breeds, which may reflect different demographic population histories and differences in intensity of selection.

Genetic Differentiation of the Two Types of Polish Cold-blooded Horses Included in the National Conservation Program.

Simple SummaryIn this study we investigated the degree of genetic differentiation among two types of Polish cold-blooded horses, namely Sokólski and Sztumski. Both these horse types are a subject of conservation breeding as their populations have been dramatically reduced during recent decades. These cold-blooded horses are considered as separate breeds, with separate stud books, but yet still their genetic differentiation has not been precisely determined, especially on the genome–wide level. In this study, we characterized genetic differentiation of these two horse populations as well as their genetic variation, admixture patterns, and level of relatedness within populations with the use of single nucleotide polymorphism (SNP) genotyping arrays. We also attempted to detect genome regions with the largest genetic differences between those horses by the detection of so-called diversifying selection signals. The results of this study provide initial evidence supporting decisions made during conservation breeding program design and answer some of the questions raised by the breeders of Sokólski and Sztumski horses.The current role of the horse as a companion animal resulted in a decrease of interest in breeding and usage of draft horses. This meant that the population of cold-blooded horses in Poland has been dramatically reduced during the last decades. To avoid impoverishment of the gene pool of the local horse population, a conservation program was established which involves draft horses and other local horse breeds. The draft horses bred in Poland can be subdivided in a few horse types of which the most widespread and consolidated are Sztumski and Sokólski horses. These two subpopulations are phenotypically diversified, however, the overall level of their genetic differentiation seems to be relatively low and not precisely determined, especially with the use of molecular markers. In reference to this, in this study we used Illumina genotyping arrays to describe in detail the genetic differentiation of these two cold-blooded horse populations. We describe the genetic distance between them, as well as within-population variation, admixture patterns, and level of relatedness within populations. We also made an attempt to detect genome regions divergently selected between those horses by the detection of diversifying selection signals. The results of this study provide initial evidence supporting breeding decisions that were made during conservation breeding program design and answer questions raised by the breeders of Sokólski and Sztumski horses concerning the level of their genetic variation and differentiation.

Inter- and intrabreed diversity of the major histocompatibility complex (MHC) in primitive and draft horse breeds.

BackgroundPolymorphism of major histocompatibility complex (MHC) genes ensures effective immune responses against a wide array of pathogens. However, artificial selection, as performed in the case of domestic animals, may influence MHC diversity. Here, we investigate and compare the MHC diversity of three populations of horses, for which different breeding policies were applied, to evaluate the impact of artificial selection and the environment on MHC polymorphism.MethodsSamples of DNA were taken from 100 Polish draft horses, 38 stabled Konik Polski horses and 32 semiferal Konik Polski horses. MHC alleles and haplotype diversity within and between these populations of horses was estimated from 11 MHC microsatellite loci.ResultsMHC diversity measured based on allelic richness, observed heterozygosity, expected heterozygosity and polymorphism content was similar across the MHC microsatellite loci in all three populations. The highest expected heterozygosity was detected in semiferal primitive horses (He = 0.74), while the lowest was calculated for draft horses (He = 0.65). In total, 203 haplotypes were determined (111 in Polish draft horses, 43 in semiferal Konik Polski horses and 49 in stabled Konik Polski horses), and four haplotypes were shared between the two populations of Koniks. None of these haplotypes were present in any of the previously investigated horse breeds. Intra-MHC recombination events were detected in all three populations. However, the population of semiferal Konik horses showed the highest recombination frequency among the three horse populations. In addition, three recombination events were detected.ConclusionsThese results showed that despite the different breeding policies, the MHC allele and haplotype diversity was similarly high in all three horse populations. Nevertheless, the proportion of new haplotypes in the offspring was the highest in semiferal Konik Polski horses, which indicates the influence of the environment on MHC diversity in horses. Thus, we speculate that the genetic makeup of the domestic horse MHC might be more strongly influenced by the environment than by artificial selection. Moreover, intra-MHC conversion, insertion, and deletion and intra-MHC recombination may be proposed as mechanisms underlying the generation of new MHC haplotypes in horses.

Polish Pony Changes Lower Layer Biodiversity in Old Growth Scots Pine Stands

The study examines the influence of Polish primitive horse grazing on vegetation in deciduous and coniferous old forest stands in north-east Poland. It was conducted in both forest sites in two complexes located in: (i) the fenced area of the Popielno Research Station of the Polish Academy of Sciences, with free-living Polish pony [Polish primitive horse (Equus ferus caballus Linnaeus, 1758)] in 130-year-old stands, and (ii) in the open 116-year-old managed (harvested) Maskulińskie Forest District, without horses. In both areas the stands are inhabited by free-living red and roe deer. The impact of forest animals on ground cover layer as well as on understory shrub layer and undergrowth was compared. Very significant differences in the structure of the understory and undergrowth (above 0.5 m) layer vegetation communities between both areas and type of stands were found. The results suggest that the presence of the Polish horse substantially changed the species composition and increased the species diversity of the ground layer and shrub layer both in the coniferous forest and deciduous forest habitats. The height of the shrub layer trees was lower by 30% in the area with the Polish horse. The level of biodiversity of forest plants was dependent on the presence of the Polish horse, which in the past was one of the natural inhabitants of forests in the area of research.

TBX3 and ASIP genotypes reveal discrepancies in officially recorded coat colors of Hucul horses

Although only a few specific pigmentation types are allowed within the Hucul horse registry, accurate determination of particular coat colors can be uncertain due to the presence of variation in color shades and segregation of multiple dun dilution variants. Herein, we genotyped the previously identified polymorphisms within two coat color loci TBX3 (T-box 3) and ASIP (Agouti Signaling Protein) in 462 Hucul individuals and compared the genotype predicted phenotypes with observed pigmentation types provided in the Polish Horse Breeders Association database. We identified disagreement between the predicted and recorded coat color in 157 horses (34%). The most common error was misclassification of horses with the nd1/nd1 and nd1/nd2 genotypes, what may be related with the occurrence of some ‘intermediate’ dilution phenotypes in such individuals. We have also proven that the frequency of the dominant dun dilution allele (D) (0.30) is higher than previously predicted by available studbooks. The D allele(s) is easily ‘hidden’ in various phenotypic groups including dark bay and black, therefore we hypothesized that the dun dilution effect itself is not as strongly epistatic in the Hucul horse as described in other horse breeds. This may be the result of an additional genetic modifier suppressing D allele phenotypic effect.

Genetic evaluation of bovine papillomavirus types detected in equine sarcoids in Poland.

Equine sarcoids are the most common neoplasms in horses. Bovine papilloma- virus type 1 (BPV-1) is the main viral type identified in equine sarcoids in Europe. The aim of the present study was to genetically evaluate BPV types based on DNA analyses of the CDS of the L1 gene. The presence of BPV DNA was confirmed by Degenerate Oligonucleotide-Primed Polymerase Chain Reaction (DOP PCR) with FAP59/FAP64 consensus primers. The DNA was detected in 21/40 (52.5%) of clinically diagnosed sarcoids. More than half of 14 isolates (66.7%) shared 100% homology with BPV-1 Deltapapillomavirus 4 isolate 09 asi UK (Acc. No. MF384289) and 99% nucleotide identity with BPV-1 isolate EqSarc1 (Acc. No. JX678969). A comparison with BPV-1 isolate EqSarc1 revealed one silent mutation in C5827T which did not change the aminoacid codon. The remaining 6 isolates (28.6%) shared 100% nucleotide identity with the BPV-1 (Acc. No. X02346) "wild type" isolate, and 1 isolate (4.8%) demonstrated 99% nucleotide identity with BPV-2 (Acc. No. M20219). Variants of BPV-1 isolate EqSarc1 (Acc. No. JX678969) constitute the most prevalent type of BPV-1 in Polish horses.

Polymorphisms in selected genes and analysis of their relationship with osteochondrosis in Polish sport horse breeds

The aim of this research was to evaluate the polymorphisms of selected genes and to find their potential effect on the occurrence of osteochondrosis in Polish Warmbloods (sport horse breeds). The study was conducted on a group of 198 horses subjected to official performance tests. Investigated joints-fetlock, hock and stifle-were X-rayed twice, once before and again at the end of the tests (first and second examination), and on this basis the degree of disease was evaluated. Based on the results of previous research, 13 candidate genes potentially associated with the occurrence of osteochondrosis were selected and, among them, 32 polymorphisms were tested. Seven SNPs located in the MATN1, CPVL, HYAL1, XIRP2, FRZB, COL5A2 and IGF1 genes were found to be associated with occurrence of osteochondrotic lesions in different joints. These intragenic polymorphisms seem to provide valuable information about the genetic basis of osteochondrosis in sport horse breeds.

Prevalence and sequence analysis of equid herpesviruses from the respiratory tract of Polish horses

BackgroundEquid herpesviruses (EHVs) are widespread in equine populations worldwide. While the infection with equine α-herpesviruses (EHV-1 and EHV-4) has been linked to several clinical outcomes, the pathogenic potential for equine γ-herpesviruses (EHV-2 and EHV-5) is still unclear. The objective of the current study was to determine the prevalence of infection with EHVs among Polish horses, to investigate factors associated with EHV infections among horses sampled, and to determine genetic variability within Polish EHV-2 isolates.MethodsVirus-specific real-time PCR assays were used for detection of EHV-1, EHV-2, EHV-4 and EHV-5 in nasal swabs collected from 540 horses from 13 national horse studs located throughout Poland. A proportion of EHV-2/5 positive samples were subjected to virus isolation followed by amplification and analysis of partial glycoprotein B sequence.ResultsOverall, 448/540 (83.0%) horses sampled were positive for at least one virus. The most prevalent was infection with EHV-2 (77.2%), followed by EHV-5 (47.0%), and EHV-4 (0.4%). None of the horses was positive for EHV-1. Approximately half of the virus-infected horses were positive for both EHV-2 and EHV-5. The proportion of EHV-2/5 positive horses varied by age, breed, and season. Only 8.0% of horses sampled, mostly Arabians, showed clinical signs of respiratory disease at the time of sampling. The viral load of both EHV-2 and EHV-5 DNA was highest in swabs from young horses, which was particularly evident for EHV-2 infected foals. Mean viral loads in nasal swabs collected from diseased horses were higher than in swabs from healthy horses. That was also true for EHV-2 when only diseased Arabian foals were considered, but the levels of EHV-5 DNA were lower in swabs from diseased than from healthy foals. In agreement with other studies, there was a considerable variability between Polish EHV-2 sequences, with no clustering of sequences from horses with different health status. The level of EHV-2 variability seemed to differ between different studs/breeds.ConclusionsThe presence of foals and yearlings on a property is likely to increase the risk of active EHV-2/5 infection among in-contact horses. The existence of breed-specific differences in susceptibility to EHV-2/5 infections should be further investigated, as it may provide one variable that needs to be considered in attempts to associate EHV-2/5 infections with disease. Overall, the data presented add to the existing knowledge of the epidemiology and biology of equine γ-herpesviruses, with the long-term goal of better understanding of the pathogenesis and the impact of infections with these viruses on the well-being of the horse.

Taste Preferences of Horses in Relation to Their Breed and Sex

The aim of this study was to determine the taste preferences of horses in relation to their breed and sex. Forty-eight adult purebred Arabian, Anglo-Arabian, Polish Konik, and Polish cold-blooded horses—stallions and mares in equal numbers—were examined in the study. During the experiment, five types of industrially processed feeds based on oats and natural dried products commonly regarded as horse treats (i.e., sour and sweet apples, carrots, sugar beet molasses, and barley with salt) were given to horses in buckets on three consecutive days. The behavior of the horses during the experiment was evaluated, as was the way in which they expressed their taste preferences, the sequence in which they consumed the pellets, the time they took to become interested in the pellets, and the time they took to consume each kind of pellet. The taste preferences of the horses were found to depend on their breed and sex. Pellets containing molasses were consumed more willingly by mares than stallions. Feeds with the addition of apples or carrots were the favorite treats of all tested breeds. The greatest variety in pellet taste preferences was found in purebred Arabian horses. Pellets with a distinct sweet taste or slightly salty cereals should be given to horses if other options are not available. In most cases, these two additions were chosen last by the horses in the experiment. Primitive horses had a distinct manner of expressing taste sensations. Horse behavior indicating an interest in a feed should not be taken as a proof of its tastiness. The first food chosen is not necessarily the one consumed most quickly.

Genetic diversity and population structure of Polish Arabian horses assessed through breeding and microsatellite data.

Polish Arabian horses are one of the most important populations of this breed in the world. Their post-war history can be divided into two periods, with the dominant role of state studs until 1989, and the increasing significance of private breeding in the next years. The goal of the study was to evaluate genetic diversity and structure of the population under a new breeding policy. The analyses of breeding and microsatellite data from 1996 to 2012 provide a coherent picture of the population with constant flow of horses only in one direction from state to private studs. An increase in the number of broodmares was observed, from 396 mares in 1996 to 1021 mares in 2012. The proportion of foreign sires used in Polish studs also increased, from 7.1% to 37.0%. An increasing number of alleles and progressive differentiation in mares were observed. STRUCTURE analysis indicated that the Polish horses were clearly separated from foreign horses used in Polish breeding, although only one of the 75 alleles found can be considered as typically Polish. The high heterozygosity is an important feature of the Polish population; however, the decrease of heterozygosity in state broodmares was noted. This issue needs to be studied further.

The prevalence of ocular diseases in polish Arabian horses

BackgroundEquine ocular diseases pose a medical challenge due to long-lasting and cost-consuming therapies as well as economic issues associated with potential decrease in value of affected horses. The scale of the problem is significant but difficult to precisely define because epidemiological data is limited and lacks consistency in presentation. To date, no retrospective studies specifically investigating Arabian horses have been published.ResultsThe aim of this cross-sectional study was to investigate the prevalence of ocular lesions and define the ocular diseases present in Arabian horses from breeding farms in Poland. Clinical and ophthalmic examination of 615 Arabian horses at Polish breeding farms (15% of Arabian population in Poland) were performed and medical history from the previous 5 years was analyzed. Data was obtained from review of veterinary archives and epidemiological interview of the resident veterinarian at each farm. The prevalence of ocular diseases was 9.75%. The following pathologies were diagnosed (with their respective prevalence): equine recurrent uveitis (ERU; 5.5%); cataract not related to ERU (3.3%); non-visual eyes (1.13%); posttraumatic lesions (0.8%); glaucoma (0.16%).ConclusionsIn this study, ERU was the most common ocular disease identified in Arabian horses in Poland. Its prevalence was lower than usually reported in Europe and the United States. There was no sex or farm predisposition but ocular disease prevalence increased with age. Other severe ocular pathologies were also observed, confirming that ocular diseases remain an important clinical problem.