Topic:Endangered Species
The topic of endangered species and horses explores the intersection of conservation efforts and equine populations that are at risk of extinction. This area of study focuses on identifying horse breeds and wild equine species whose numbers have declined significantly due to factors such as habitat loss, climate change, and human activities. It examines the genetic diversity, population dynamics, and conservation strategies aimed at preserving these at-risk groups. The topic includes research on the ecological roles of these horses, their historical significance, and the challenges involved in their conservation. This page compiles peer-reviewed research studies and scholarly articles that investigate the status, threats, and preservation efforts related to endangered horse species and breeds.
Comparative chromosomal studies of E. caballus (ECA) and E. przewalskii (EPR) in a female F1 hybrid. Previous research revealed that the karyotypes of Equus przewalskii (2n = 66) and Equus caballus (2n = 64) differ by one pair of metacentric chromosomes, present in ECA but not in EPR, and two pairs of acrocentric chromosomes found only in the EPR karyotype. The formation of a trivalent during meiosis in a male F1 hybrid and the homologies in G-banding patterns suggest that ECA 5 corresponds to two acrocentric EPR chromosomes resulting from a Robertsonian fusion or fission event. Chromosomal investigations of a female interspecies F1 hybrid including banded karyograms and fluorescence in situ ...
Genetic variation of Polish endangered Biłgoraj horses and two common horse breeds in microsatellite loci. Genetic variation of endangered Biłgoraj horses and two common Polish horse breeds was compared with the use of 12 microsatellite loci (AHT4, AHT5, ASB2, HMS2, HMS3, HMS6, HMS7, HTG4, HTG6, HTG7, HTG10, VHL20). Lower allelic diversity was detected in all investigated populations in comparison to other studies. Large differences in the frequencies of microsatellite alleles between Biłgoraj horses and two other horse breeds were discovered. In all polymorphic loci all investigated breeds were in the Hardy-Weinberg equilibrium. Mean Fis values and the results of a test for the presence of a rec...
Experience from Lipizzan horse and salmonid species endemic to the Adriatic river system. Examples for the application of molecular markers for preservation of biodiversity and management of animal genetic resources. Management of breeding- and free-living populations, traditionally based on phenotypic traits, relays more and more on availability of reliable information about the basic population genetic parameters as heterozygosity, mean number of alleles per locus, percentage of polymorphic loci, population structuring, genetic distances and others. Therefore, the application of molecular markers, revealing a great deal of phenotypically hidden information, becomes inevitable for population analysis. Conservation geneticists use this information for implementation of appropriate management policies. Appl...
Integration of sperm sexing technology into the ART toolbox. Sex-sorting of mammalian spermatozoa has applications for genetic improvement of farm animals, in humans for the control of sex-linked disease, and in wildlife as a captive management strategy and for the re-population of endangered species. Considerable research has been undertaken worldwide on the Beltsville sperm sexing technology, the only effective method for pre-selection of sex of offspring. The combination of this method with assisted reproductive technologies has resulted in the birth of offspring in a wide range of animals, including cattle, the only livestock species in which sperm ...
Coccidioidomycosis in Przewalski’s horses (Equus przewalskii). Coccidioidomycosis is a rare, often subclinical infection in domestic animals caused by the fungus Coccidioides immitis. Because of an apparent high incidence of coccidioidomycosis in Przewalski's horses (Equus przewalskii) housed at a single facility, necropsy records and biomaterials from animals that died between 1984 and 2000 were reviewed (n = 30, 15 males, 15 females). Coccidioidomycosis was the leading cause of death (33%) in this population with lesions in the lungs and tracheobronchial lymph nodes of all animals and variable involvement of the skeletal muscle, heart, kidney, liver, sk...
[Genealogic analysis of hereditary components of a metapopulation of Przhevalsky horse]. The current condition of the megapopulation of the Przhevalsky horse was assessed using genetic indices of biological diversity of species and genealogical analysis and taking into account both nuclear and non-nuclear (mitochondrial), maternally inherited components of hereditary information.
Genetic variation in Przewalski’s horses, with special focus on the last wild caught mare, 231 Orlitza III. In our continuing efforts to document genetic diversity in Przewalski's horses and relatedness with domestic horses, we report genetic variation at 22 loci of blood group and protein polymorphisms and 29 loci of DNA (microsatellite) polymorphisms. The loci have been assigned by linkage or synteny mapping to 20 autosomes and the X chromosome of the domestic horse (plus four loci unassigned to a chromosome). With cumulative data from tests of 568 Przewalski's horses using blood, hair or tooth samples, no species-defining markers were identified, however a few markers were present in the wild spe...
Laminitis in Przewalski horses kept in a semireserve. Semireserves were created by the European Conservation Project for scientific research in preparation for reintroduction in the wilderness. They are defined as enclosures large enough to carry a group of Przewalski horses throughout the year without any additional feeding. The semireserve offers diverse opportunities for significant scientific research. As part of a general screening program, the hoof development in a group of Przewalski horses was investigated in the semireserve Schorfheide near Berlin. Since the foundation of this semireserve in 1992, veterinary treatment was not necessary w...
Intracapsular lens removal in a Przewalski’s wild horse (Equus caballus przewalskii). A 11.5-yr-old female Przewalski's wild horse (Equus caballus przewalskii) presented for unilateral blepharitis and drainage from the left eye. The left cornea was not ulcerated, and intraocular evaluation was hampered by severe corneal edema. The left eye appeared to respond positively to treatment with anti-inflammatories and a topical mydriatic agent. During the ensuing 2 yr, there were minor episodes of epiphora from the left eye. The discharge then increased, and a luxated lens was noted during an examination by a veterinary ophthalmologist as part of the preshipment examination. Initially...
Semen parameters and level of microsatellite heterozygosity in Noriker draught horse stallions. It was the aim of the present study to determine physiological values for different semen parameters in an endangered draught horse breed, the Austrian Noriker. Because small population size is often believed to cause a decrease in fertility and/or semen quality through inbreeding and a reduction in genetic variation, the general genomic heterogeneity of the breed was estimated on the basis of microsatellite variation and correlated to semen parameters. Semen could be collected from 104 of 139 stallions with semen collection being more often successful in younger stallions. Mean volume of ejac...
New commercial opportunities for advanced reproductive technologies in horses, wildlife, and companion animals. As advanced reproductive technologies become more efficient and repeatable in livestock and laboratory species, new opportunities will evolve to apply these techniques to alternative and non-traditional species. This will result in new markets requiring unique business models that address issues of animal welfare and consumer acceptance on a much different level than the livestock sector. Advanced reproductive technologies and genetic engineering will be applied to each species in innovative ways to provide breeders more alternatives for the preservation and propagation of elite animals in eac...
Reversibility of action and safety during pregnancy of immunization against porcine zona pellucida in wild mares (Equus caballus). Contraceptive management of publicly valued wildlife species requires safeguards to ensure that these populations are preserved in a healthy state. In addition, reversibility of contraceptive effects and safety in pregnant animals are major concerns. A population of wild horses has been immunized against porcine zona pellucida (PZP) over a 12 year period on Assateague Island National Seashore, MD (ASIS). Mares initially received one or two 65 microg inoculations and once a year 65 microg booster inoculations, all delivered by dart. All young mares aged > 2 years were treated with PZP for 3 ...
Computer simulations to determine the efficacy of different genome resource banking strategies for maintaining genetic diversity. Genome resource banks (GRBs) and assisted reproductive techniques are increasingly recognized as useful tools for the management and conservation of biodiversity, including endangered species. Cryotechnology permits long-term storage of valuable genetic material. Although, the actual application to endangered species management requires technical knowledge about sperm freezing and thawing, a systematic understanding of the quantitative impacts of various germ plasm storage and use scenarios is also mandatory. In this study, various GRB strategies were analyzed using the historical data from th...
Genetic diversity in Spanish donkey breeds using microsatellite DNA markers. Genetic diversity at 13 equine microsatellite loci was compared in five endangered Spanish donkey breeds: Andaluza, Catalana, Mallorquina, Encartaciones and Zamorano-Leonesa. All of the equine microsatellites used in this study were amplified and were polymorphic in the domestic donkey breeds with the exception of HMS1, which was monomorphic, and ASB2, which failed to amplify. Allele number, frequency distributions and mean heterozygosities were very similar among the Spanish donkey breeds. The unbiased expected heterozygosity (H(E)) over all the populations varied between 0.637 and 0.684 in t...
Functional and computer modelling studies of haemoglobin from horse. The haemoglobin system of the Sardinian wild dwarf horse. A study was made of the haemoglobin (Hb) system from the Sardinian dwarf horse (Equus caballus jara), one of the last surviving wild horse species in Europe. The oxygen binding properties of the whole haemolysate and of the four different horse Hbs, separated by ion-exchange chromatography, were studied with special regard to the effect of chloride, 2,3-diphosphoglycerate and lactate. Results indicate that no significant functional differences exist between the four Hb components of horse haemolysate. Moreover, the molecular basis of the intrinsically low oxygen affinity and of the weak intera...
CT examination of the guttural pouch (auditory tube diverticulum) in Przewalski’s Horse (Equus przewalskii). The domestic horse (Equus caballus) have the large symmetrical guttural pouches (the auditory tube diverticulum) formed by saccate bulge of the auditory tube. In this study, CT examination was carried out in the head of Przewalski's horse (Equus przewalskii), the only true wild horse living at present. As results of the examination, Przewalski's horse possessed the large symmetrical guttural pouches divided into medial and lateral compartments by the stylohyoid bone. Moreover, the right and left guttural pouches meet each other at the median part to form a thin septum. As CT sections get close...
Major histocompatibility complex variation in the endangered Przewalski’s horse. The major histocompatibility complex (MHC) is a fundamental part of the vertebrate immune system, and the high variability in many MHC genes is thought to play an essential role in recognition of parasites. The Przewalski's horse is extinct in the wild and all the living individuals descend from 13 founders, most of whom were captured around the turn of the century. One of the primary genetic concerns in endangered species is whether they have ample adaptive variation to respond to novel selective factors. In examining 14 Przewalski's horses that are broadly representative of the living animal...
Mitochondrial control region and 12S rRNA variation in Przewalski’s horse (Equus przewalskii). Variation in the control region and the 12S rRNA gene of all surviving mitochondrial lineages of Przewalski's horse was investigated. Variation is low despite the present day population being descended from 13 individuals probably representing animals from three different regions of its range. Phylogenetic comparison of these sequences, with sequences for the domestic horse, does not resolve the ancestral status of either horse.
[The intraspecific differentiation of Przhewalski’s horse and the domestic horse by 5 molecular genetic markers]. Analysis of albumin, transferrin, receptor to vitamin D, esterase, alpha 1-beta glycoprotein polymorphisms in Przhewalski's horse, Orlov's and Russian trotters, Guzul and Yakutian domestic horse breeds was carried out. The data about similarity of intraspecies differentiation of Przewalski's horse's populations and interbreed distinctions were obtained. Locus-specific particularities of genetic structures of investigated animal groups were revealed.
Polymorphism of Old Kladruber horses, a surviving but endangered baroque breed. Analysis of MHC class I and class II polymorphism, as well as data from other polymorphic systems (non-MHC lymphocyte alloantigen, blood groups systems, biochemical polymorphisms and microsatellite loci), was used to characterize the extent and distribution of the genic polymorphism of Kladruber horses. A breed-characteristic distribution of the MHC polymorphism was found. The repertoire of defined MHC class I specificities was restricted, especially in the grey subpopulation and in stallions, but a high frequency of blanks suggests the possible existence of undetected specificities. Despite t...
[Are zoo Przewalski horses domesticated horses?]. Analysed were the brain case capacities and brain weights of wild przewalski horses, przewalski horses from zoological gardens and domesticated horses. Domesticated horses have about 14% less brain case capacity and 16% less brain weight than wild przewalski horses. Przewalski horses from zoological gardens also have about 14% less brain capacity than wild przewalski horses. The brain weight of przewalski horses from zoological gardens shows no difference to the brain weight of domesticated horses. If we look at the brain size, przewalski horses from zoological gardens are domesticated horses....
Clinical biochemical parameters of the endangered Catalonian donkey breed: normal values and the influence of sex, age, and management practices effect. Twelve clinical biochemical parameters were determined in 97 animals of all age groups and both sexes of the endangered Catalonian donkey breed. Significant sex differences were observed for phospholipid concentration (P<0.01). Evaluating the effect of management practices on the various parameters showed significant differences for total bilirubin (P<0.001) and creatinine (P<0.05) concentrations and gamma-glutamyltransferase (P<0.05) activity. Moreover, it was observed that inorganic phosphorus concentration decreased with age (P<0.001), whereas albumin and triglyceride concent...
Plasma alpha-tocopherol, beta-carotene, and lipid levels in semi-free-ranging Przewalski horses (Equus przewalskii). Circulating concentrations of alpha-tocopherol, beta-carotene, and lipids were quantified in 19 Przewalski horses (Equus przewalskii) inhabiting the steppes of Ukraine during June 1991. Foals (n = 3) had lower mean plasma alpha-tocopherol (4.7 micrograms/ml) and beta-carotene (0.3 microgram/ml) levels than did adults (n = 16; 6.6 and 0.7 micrograms/ml, respectively) and higher mean cholesterol concentrations (1.42 vs. 0.98 mg/ml). Mean triglyceride levels did not differ between foals and adults (0.46 mg/ml). Alpha tocopherol concentrations were substantially higher than those considered normal...
The hemoglobin polymorphism of the Sardinian wild dwarf horse and the oxygen binding properties of the four different horse hemoglobins. A study was made of the Hb phenotype of the Sardinian dwarfhorse (Equus caballus jara), one of the last surviving wild horse species in Europe. Hb haplotypes and their frequencies were found to be similar to those described in the Arabian horse (BI = 0.551, BII = 0.389, A = 0.036, V = 0.015), which suggests possible introduction onto the island from North Africa. The oxygen binding properties of the whole hemolysates and of the four different horse Hbs, separated by ion-exchange chromatography, were considered with regard to the effect of chloride, 2,3-bisphosphoglycerate and lactate. Results ...
[Preservation of genetic variation in domestic animals using biotechnical methods]. The conservation of endangered breeds as live animals is at present the main national strategy of the government and breeding organizations to maintain genetic diversity. Fourty-three breeds and some old strains of cattle, pig, sheep, goat and horses are currently involved. Cryopreservation and banks for sperm, embryos or DNA are another type of genetic material which could subsequently be used for breeding and production in agriculture. Present semen banks involve 9 endangered cattle breeds and also a small amount of deep-frozen sperm of some endangered sheep and horse breeds. Only 2 embryo b...
Rare alleles, MHC and captive breeding. 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...