Donkey Populations Research Articles

Phenotypic Clustering of Indian Donkey Population Belonging to Six Agro-Climatic Regions

Donkeys support rural livelihoods and low-income farmer’s family by providing economy at minimal maintenance cost. In India, donkeys constitute about 28% of total equine population but these are non-descript local donkeys without any breed characterization. This study describes phenotypic diversity among different donkey populations available in various agro-climatic regions in India including Gujarat, Rajasthan, Maharashtra, J&K, Haryana, Bihar and Himachal Pradesh for their phenotypic clustering as a distinct breed(s) by considering each population as a separate cluster. Biometric indices of seven local donkey populations were recorded and compared to French Poitou donkey breed which revealed that average body length of donkeys from Spiti, Gujarat, Rajasthan, Baramati, Bihar, Haryana and Leh areas was 97.09, 101.18, 97.60, 103.68, 96.31, 109 & 95.76 cm, respectively, while Poitou donkeys had significantly higher length (138.79 cm) than indigenous donkey populations. Further height at wither revealed that except leh donkey population, the rest of the donkeys prevalent throughout different agro-climatic regions met a “small standard’ pattern. Donkey populations from Leh were fitted in ‘Miniature’ donkey pattern. All local donkeys were well adapted to their agroclimatic environment and ecology as they were totally dependent upon the grass cover and roughages available within their reach for meeting their nutritional requirement. Coat colour varied across different regions. Black and brown colours were prevalent in donkeys from cold desert regions including Leh and Spiti region. Face length of donkeys from Spiti, Gujarat and Baramati were at par with each other while donkeys from Leh had smallest face length. Cluster analysis based on biometric indices revealed that exotic Poitou donkeys is an out-group as it formed a distinct cluster while Indigenous donkeys belonging to various agro-climatic zones were grouped in three clusters namely, C1-miniature or near miniature donkeys (Leh, Spiti and Bihar regions), C2- small standard ones including donkeys from Rajasthan and Gujarat while cluster C3 having donkeys from Baramati and Haryana region. Poitou cluster was phenotypically different from Cluster 1 as Eucledean cluster distance was maximum with donkeys of this cluster, followed by cluster 2 and cluster 3. This information will be useful for breed classification of these local non-descript donkeys.

A model to infer the demographic structure evolution of endangered donkey populations

Stemming from The Worldwide Donkey Breeds Project, an initiative aiming at connecting international researchers and entities working with the donkey species, molecularly tested pedigree analyses were carried out to study the genetic diversity, structure and historical evolution of the Andalusian donkey breed since the 1980s to infer a model to study the situation of international endangered donkey breeds under the remarkably frequent unknown genetical background status behind them. Demographic and genetic variability parameters were evaluated using ENDOG (v4.8). Pedigree completeness and generation length were quantified for the four gametic pathways. Despite mean inbreeding was low, highly inbred animals were present in the pedigree. Average coancestry, relatedness, and non-random mating degree trends were computed. The effective population size based on individual inbreeding rate was about half when based on individual coancestry rate. Nei’s distances and equivalent subpopulations number indicated differentiated farms in a highly structured population. Although genetic diversity loss since the founder generations could be considered small, intraherd breeding policies and the excessive contribution of few ancestors to the gene pool could lead to narrower pedigree bottlenecks. Long average generation intervals could be considered when reducing inbreeding. Wright’s fixation statistics indicated slight inbreeding between farms. Pedigree shallowness suggested applying new breeding strategies to reliably estimate descriptive parameters and control the negative effects of inbreeding, which could indeed, mean the key to preserve such valuable animal resources avoiding the extinction they potentially head towards, making the present model become an international referent when assessing endangered donkey populations.

Dynamics in the devolopment of donkey population in Bulgaria

Dynamics in the devolopment of donkey population in Bulgaria

Contributions to diversity rather than basic measures of genetic diversity characterise the spreading of donkey throughout the American continent

Donkey was introduced into the Americas soon after its discovery in the 15th century. However, there is no historical consensus on how they spread across the continent. In a previous study, two distinct genetic pools (Clusters A -Southern part - and B -Northern part of South America and Central America) were identified, with likely confluence in Colombia. The aim of this study was to evaluate whether the main genetic diversity parameters, such as gene diversity (GD) and allelic richness (k), or the relative contributions of various breeds to these parameters are useful indicators to give genetic support to historical information on putative routes of the spreading of donkeys across the American continent. In full agreement with historical sources suggesting that Greater Antilles were the first breeding nucleus, both total contributions to gene diversity (gGDT) and to allelic richness (CT(k)) showed a higher ability to identify the "abundant centre" of the species on the Continent. Even though there are historical reports suggesting various entry points of the donkey into the continent (e.g. in Brazil), these parameters suggested that, in our dataset, the Cuban donkey population was the more likely representative of the first breeding nucleus of the species. Central and South American donkey populations in the surroundings of the Caribbean Gulf would more likely be early derivatives of Antillean donkey. The strong North-South genetic structure was confirmed for the American donkey metapopulation. Current analyses suggest that populations classified into Cluster A (South) are essentially a sample of the genetic background of Cluster B (North). The Andean route had the highest importance in the formation of the South American populations. The extinction of either population belonging to Cluster B could lead to a decrease in overall genetic diversity both at the gene diversity level (negative gGDT values) and the allelic richness level (positive CT(k) contributions). The opposite pattern is found for populations belonging to Cluster A. The extinction of the populations belonging to Cluster B would decrease the overall American donkey gene diversity in roughly 8% and would dramatically affect the number of alleles in the metapopulation (19.1%). However, the extinction of the donkey populations classified into Cluster A would increase overall gene diversity by 2.2%. Although, the genetic scenario of each individual population varies substantially, the joint conservation of the donkey populations classified into both Clusters A and B is highly advised.

Prevalence of cardiovascular disease in donkeys

THE world's donkey population is estimated at 44 million, compared to about 58 million horses (FAO 2007). In developed countries, donkeys are often considered less economically valuable than horses. However,...

Echocardiographic reference ranges for sedentary donkeys in the UK

The aim of this study was to provide two-dimensional (2D) and M-mode echocardiographic reference ranges from a sample of the UK population of donkeys including geriatrics (>30 years), owned by...

Transrectal ultrasonographic evaluation of combined utero-placental thickness during the last half of pregnancy in Martina Franca donkeys

In the recent years, the donkey population decreased dramatically so that many breeds are presently considered as endangered. In comparison to the horse, the donkey placenta still remains not completely studied. In the horse, one of the diagnostic tools useful to identify pregnant mares at risk of abortion or premature delivery, include the transrectal ultrasound examination of the uterus and its contents; and especially of the combined thickness of the uterus and of the placenta (CUPT). Since the CUPT was never investigated in donkeys, the present study was aimed to define the transrectal CUPT values during the last half of pregnancy in 20 Martina Franca jennies. Foalings times, foals characteristics and placental gross appearance, and measurements were also evaluated and values resulted always within normality. Differently to the mare, a continuous significant CUPT increase between the sixth to the 12 months of pregnancy, and a substantial increase from the ninth to the 12th month of pregnancy, was found. Although statistically not evaluable, the CUPT values recorded from three jennies with pregnancy loss did not show evidence of CUPT increases. In conclusion, normal CUPT values from the sixth to the 12th month of pregnancy in Martina Franca donkeys are provided, but further investigations are needed to define possible breed or body-size CUPT specific differences, as well as the CUPT values during pregnancy disturbances or placental abnormalities.

Biochemical profiles of Indian donkey population located in six different agro-climatic zones

To establish normal values of blood biochemical indices for different indigenous local donkey population available in various agro-climatic zones, blood samples were collected from 233 adult and apparently healthy donkeys. The samples were analysed for metabolites (albumin, total serum protein, direct bilirubin, total bilirubin, cholesterol, HDL cholesterol, urea, uric acid, triglyceride, creatinine) and minerals (calcium, phosphorus) to evaluate significant difference within and between populations. Confidence limit of each biochemical indices showed a close range as compared to their actual range observed under varied geographic areas. All the metabolites and minerals showed significant variations in their levels within and between donkey populations which could possibly be due to the differences in the nutritional status of donkeys, their managemental aspects and biochemical metabolism. In agro-climatic zone 1 (Spiti and Leh areas), having low vegetation cover with poor nutritious grasses for a limited period, levels of most of the biochemical profiles in donkey populations belonging to these areas were significantly lower than those in other zones (VI, IX, XII, XIV). This study indicated that normal biochemical values of different indices for a particular population should not be used as such for disease prognosis, diagnosis and therapeutic monitoring of other donkey population belonging to other agro-climatic zone having different nutritional and managemental practices.

Molecular phylogeny of Anatolian and Cypriot donkey populations based on mitochondrial DNA and Y-chromosomal STRs

Evciltme bölgeleri ve modern evcil eşek populasyonuna katkıda bulunan soylar, Nubian yaban eşeği hariç, hala bilinmemektedir. Bu çalışma Anadolu eşeğinin evciltmesi hakkındaki boşlukların doldurulması için tasarlanmıştır. Türkiye’den 68 Anadolu eşeği ve Kıbrıs’tan yedi eşek, D-loop ve cytochrome b gen bölgeleri açısından analiz edilmiştir. İncelenen örneklerden 30 erkek aynı zamanda ata ait Eca.YM2, Eca.YP9 ve Eca.YE1 isimli üç adet Y-kromozomal kısa ardışık tekrar dizileri (STRlar) ile genotiplendirilmiştir. Anadolu eşek populasyonu D-loop sekanslarından elde edilen haplotip ve nükleotid çeşitliliği (h=0.756±0.0500 ve π=0.1688±0.0012) orta düzeyde yüksek bulunmuşken, Kıbrıs eşek populasyonunda büyük ölçüde düşük (h=0.524±0.209 ve π=0.00176 ± 0.001) bulunmuştur. Anadolu eşeklerinin %35’i Clade 1’de Nubian yaban eşeği ile kümelenmişken, kalan %65’i ve Kıbrıs eşeklerinin %100’ü Clade 2 olarak kümelenmiştir. Sunulan çalışmada Clade 2 Somali soyundan ve Asya yaban eşeklerinden genetik olarak farklı çıkmıştır. Böylece bu soyların Anadolu ve Kıbrıs eşeğinin atası olamayacakları belirlenmiştir. D-loop ve sitokrom bölgeleri için, sırasıyla, 15 ve 6 haplotip ayrımını sağlayan 17 ve 4 nükleotid değişimi belirlenmiştir. Analiz edilen Ykromozomal STR’lar monomorfik bulunmuştur. Eca.YM2, Eca.YP9 ve Eca.YE1 için sırasıyla 109, 190 ve 195 allel büyüklükleri belirlenmiştir

Selected haematological and biochemical indices in donkeys in the Czech and Slovak Republics

The aim of this study was to establish normal reference values of biochemical and haematological indices of donkeys in the Czech and Slovak Republics. Blood samples were obtained from 112 clinically healthy donkeys (37 males and 75 females). The haematological indices examined were: red blood cells, white blood cells, haemoglobin concentration, haematocrit, mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration, platelets, segmented neutrophils, neutrophil bands, lymphocytes, monocytes, eosinophils and basophils. The biochemical properties examined were: total protein, albumin, creatinine, alkaline phosphatase, aspartate aminotransferase, creatine kinase, gamma-glutamyl transferase, lactate dehydrogenase, triacylglycerols, cholesterol, calcium, phosphorus, potassium, sodium, lactate. The results reported in this study could serve as reference ranges for the donkey population in the Czech and Slovak Republics.

The albinism of the feral Asinara white donkeys (Equus asinus) is determined by a missense mutation in a highly conserved position of the tyrosinase (TYR) gene deduced protein.

A feral donkey population (Equus asinus), living in the Asinara National Park (an island north-west of Sardinia, Italy), includes a unique white albino donkey subpopulation or colour morph that is a major attraction of this park. Disrupting mutations in the tyrosinase (TYR) gene are known to cause recessive albinisms in humans (oculocutaneous albinism Type 1; OCA1) and other species. In this study, we analysed the donkey TYR gene as a strong candidate to identify the causative mutation of the albinism of these donkeys. The TYR gene was sequenced from 13 donkeys (seven Asinara white albino and six coloured animals). Seven single nucleotide polymorphisms were identified. A missense mutation (c.604C>G; p.His202Asp) in a highly conserved amino acid position (even across kingdoms), which disrupts the first copper-binding site (CuA) of functional protein, was identified in the homozygous condition (G/G or D/D) in all Asinara white albino donkeys and in the albino son of a trio (the grey parents had genotype C/G or H/D), supporting the recessive mode of inheritance of this mutation. Genotyping 82 donkeys confirmed that Asinara albino donkeys had genotype G/G whereas all other coloured donkeys had genotype C/C or C/G. Across-population association between the c.604C>G genotypes and the albino coat colour was highly significant (P = 6.17E-18). The identification of the causative mutation of the albinism in the Asinara white donkeys might open new perspectives to study the dynamics of this putative deleterious allele in a feral population and to manage this interesting animal genetic resource.

Cutaneous metabolic pathway of tyrosine as a precursor to melanin in Asinara’s white donkey, Equus asinus L., 1758

L-tyrosine (L-Tyr) is a conditionally indispensable amino acid for Equids. The biologic role of L-Tyr is ubiquitous, being involved in the production of hair and skin pigments. The white donkeys of <em>Asinara</em> island display a peculiar white coat, with life-long hypopigmentation of skin, hairs and eyes. Our results underline how the white phenotype is due to a disorder of melanin biosynthesis, detected in skin biopsies and on hair bulbs through immunohistochemical and enzymatic assays. The metabolic pathway of L-Tyr is compatible with the clinical frame of ocular-cutaneous albinism (OCA). The enzymatic activity in hair bulbs for the conversion of L-Tyr to L-3,4-dihydroxyphenilalanine (L-DOPA) tested negative, but positive for L-DOPA conversion into eumelanin in the 100% of the <em>Asinara</em>’s white donkey. This is the case of a negative-tyrosinase albinism, which contemporarily excludes dietary deficiencies of phenylalanine (Phe) or L-Tyr and potential incapability of Tyr intestinal uptake or Tyr conversion from Phe. The tyrosinase (TYR) residual activity positively and significantly (P=0.012) correlates (P=0.897) with the albino phenotype of the <em>Asinara</em>’s white donkey. These results definitely point to the fact that <em>Asinara</em>’s white donkey population owes its phenotype to TYR residual activity, thus on genetic basis. From a comparative point of view, the albino form of the <em>Asinara</em>’s white donkeys is similar to the human OCA type 1, from which however differs for positively testing to L-DOPA conversion, upon incubation of hair bulbs in L-DOPA solutions.

Genetic relationships among American donkey populations: insights into the process of colonization.

This study presents the first insights into the genetic diversity and structure of the American donkey metapopulation. The primary objectives were to detect the main structural features underlying variability among American donkey populations, identify boundaries between differentiated gene pools, and draw the main colonization pathways since the introduction of donkeys into America in the 15th century. A panel of 14 microsatellite markers was applied for genotyping 350 American donkeys from 13 countries. The genetic structure of this metapopulation was analysed using descriptive statistics and Bayesian model-based methods. These populations were then compared to a database containing information on 476 individuals from 11 European breeds to identify the most likely ancestral donor populations. Results showed the presence of two distinct genetic pools, with confluence of the two in Colombia. The southern pool showed a unique genetic signature subsequent to an older founder event, but lacked any significant influence of modern gene flow from Europe. The northern pool, conversely, may have retained more ancestral polymorphisms and/or have experienced modern gene flow from Spanish breeds. The Andalusian and, to a lesser extent, the Catalan breeds have left a more pronounced footprint in some of the American donkey populations analysed.

Status of the genetic diversity and population structure of the Pêga donkey

Pedigree analysis was extended to the Pêga donkey population in order to evaluate the status of genetic diversity and population structure. All parameters were computed for three reference populations of animals born between 2004 and 2014: all animals, animals with mouse gray coat color, and animals with roan coat color. Although the average inbreeding coefficient observed was low (about 3%), highly inbred animals are present in the current population. The effective population size based on the individual inbreeding rate was 35, while the effective population size based on the individual coancestry rate was about three times higher. The number of equivalent subpopulations was at around three, indicating that the Pêga donkey population is highly structured. There is no evidence of differentiation between subpopulations based on the coat color of the animals (Nei's minimum distance 0.10%). The breeding policy of Pêga donkeys is predominantly intra-herd. The loss of genetic diversity since the founder generations can be considered small in Pêga donkeys (1.25%). The excessive contribution of few ancestors to the gene pool may lead to narrower bottlenecks in the pedigree of this population in the future. The long generation interval in Pêga donkeys (10.7years) may be considered an advantage to reduce the increase in inbreeding and to maintain the genetic diversity of these animals.

Characteristics of Morphological Parameters of Donkeys in the Czech Republic

The donkey population in Central Europe and Czech Republic is very variation, which is a consequence of the donkeys originating from various areas of Europe. This has been proved to affect their body conformation. In this work, we are focusing on the population of donkeys in the Czech Republic and its analysis.The main aim of our work was to determine the values morphological parameters in the donkey population in the Czech Republic. Altogether, 23 body dimensions were taken and further processed to calculate 6 hippo metric indexes. The sample group we analyzed consisted by a total of 70 individuals, out of there were 23 stallions and 47 mares. The results were then processed using the methods of general linear model (GLM) and multiple comparisons.We managed to prove a statistically significant influence of the sex factor for the following body measurements: shin length of the front limbs, chest width, withers height measured by tape, shin circumference on both front and pelvic limbs and also for weight index. Also, we have found a statistically significant difference in the scapula length when considering the age factor.

Pyrantel resistance in two herds of donkey in the UK

Resistance to currently available anthelmintics is a serious phenomenon which is prevalent globally. Cyathostomins are one of the major parasites, and are of primary concern in donkeys. There have been reports of emerging resistance to pyrantel, but the status of pyrantel resistance in donkey populations in the UK is largely unknown. This report investigates pyrantel resistance in two geographically isolated donkey herds in the South West of England. The first herd had suspected pyrantel resistance, with already established resistance to other anthelmintics. In the second herd the efficacy of pyrantel was not suspected at the time the study took place. Faecal Egg Count Reduction Test (FECRT) was carried out, revealing large scale resistance. Eighty one percent of the first herd and 73% of the second herd had a FEC of less than 95% after treatment, and anthelmintic resistance was confirmed using the World Association for the Advancement of Veterinary Parasitology guidelines. These findings indicate that anthelmintic resistance to pyrantel exists in both tested donkey populations and illustrate the continuing development of resistance through different classes of chemotherapeutics.

Bacterial and fungal microflora on the external genitalia of male donkeys (Equus asinus)

This study was undertaken to investigate the bacterial and fungal microflora on the external genitalia of a population of healthy male donkeys in the state of Michigan, USA. The aim was to identify and determine the frequency of occurrence of these microorganisms using seven different isolation media and standard microbiological procedures. The sites (urethral fossa [fossa glandis], dorsal diverticulum of the urethral sinus, distal urethra, and penile surface) in the distal reproductive tract were cultured and each isolated microorganism identified. Ten different genera of gram-positive bacteria, eight different genera of gram-negative bacteria, and two genera of fungi were isolated from the external genitalia of the 43 donkeys in this study. All 43 donkeys yielded gram-positive bacteria (2–8 species) from all four sites sampled. Arcanobacterium spp., Corynebacterium spp., and Bacillus spp. were the most frequently isolated gram-positive bacteria. Gram-negative bacteria were cultured from 16 (37.2%) of the 43 donkeys, with Acinetobacterlwoffii (16.3%), Oligella urethralis (11.6%), and Taylorellaasinigenitalis (9.3%), the most frequently isolated. Fungi were cultured from only 5 (11.6%) of the 43 donkeys, with Rhizopus spp. isolated from 3 (7.0%) and Cladosporium spp. from 2 (4.7%) individuals. The testes and epididymides collected from 40 donkeys at time of castration were culture negative. Few differences were found in the bacterial flora between prepubertal and mature intact and castrated donkeys. Of notable interest was the scarcity of known equine pathogens across the population tested and isolation of T. asinigenitalis from normal donkeys, especially prepubertal individuals and previously castrated males.

Genetic diversity of donkey populations from the putative centers of domestication.

Donkey domestication drastically changed ancient transport systems in Africa and Asia, enabling overland circulation of people and goods and influencing the organization of early cities and pastoral societies. Genetic studies based on mtDNA have pointed to the African wild ass as the most probable ancestor of the domestic donkey, but questions regarding its center of origin remain unanswered. Endeavoring to pinpoint the geographical origin of domestic donkey, we assessed levels and patterns of genetic diversity at 15 microsatellite loci from eight populations, representing its three hypothesized centers of origin: northeast Africa, the Near East and the Arabian Peninsula. Additionally, we compared the donkey genotypes with those from their wild relative, the African wild ass (Equus africanus somaliensis) to visualize patterns of differentiation among wild and domestic individuals. Obtained results revealed limited variation in levels of unbiased expected heterozygosity across populations in studied geographic regions (ranging from 0.637 in northeast Africa to 0.679 in the Near East). Both allelic richness (Ar) and private allelic richness presented considerably higher values in northeast Africa and in the Arabian Peninsula. By looking at variation at the country level, for each region, we were able to identify Sudan and Yemen as the countries possessing higher allelic richness and, cumulatively, Yemen also presented higher values for private allelic richness. Our results support previously proposed northeast Africa as a putative center of origin, but the high levels of unique diversity in Yemen opens the possibility of considering this region as yet another center of origin for this species.

The role of density-dependent arrested larval stages on parasite dynamics and stability: Lessons from nematodes and donkeys

The regulation of parasite populations is a very interesting field of study, relevant for both farm and wild host species. Traditionally, the mortality of parasites due to parasite-induced host mortality has been considered the main feature giving rise to the regulation and stability of host–parasite interaction, enhanced by the negative binomial distribution of parasites in host populations. Nevertheless, different possible density-dependent mechanisms of parasite regulation are likely to occur.For small strongyles (Subfamily: Cyathostominae), the most widespread intestinal parasites of equids, one of the mechanisms possibly regulating parasite population is the negative feed-back of luminal adult parasites on mucosal larval stage development.This paper proposes a deterministic model consistent with empirical data collected on donkey small strongyles. Its most innovative aspect is the inclusion of mucosal hypobiotic larvae regulation induced by adult parasite abundance. The explicit calculation of the expected value of the larval development rate, given the negative binomial distribution of adult parasites, was provided. Parasite-induced host mortality was irrelevant in the experimental donkey population studied and not included in the model, while density-dependent mortality of endogenous parasite stages was included.The main aim was to evaluate the possible stabilizing effect of the regulation of larval development. For this purpose, the comparison of the full model with a simplified model in which development rate is a fixed parameter was performed. The behaviour of the models after additional cyclical mortality was also studied. Cyclical parasite mortality can be viewed as the result of regular anthelmintic control measures used in the field.The main result obtained is that parasite extinction due to additional cyclical mortality is more difficult to be obtained if mucosal larvae development is regulated, notwithstanding the small transmission rate of the full model. Ecological regulation of parasite dynamics appears as a significant obstacle to parasite control; in particular the regulatory effect of adult parasites on mucosal larvae development enhances parasite viability allowing parasites to reach high population abundance with lower transmission rate and represents a clear advantage in terms of parasite survival to perturbations.

Seroprevalence and risk factors associated with Babesia caballi and Theileria equi infections in donkeys from Southern Italy

Equine piroplasmosis (EP) has been frequently described in donkeys in subtropical and tropical regions, but published data reflecting large scale surveys are very limited in Europe. The seroprevalence of Babesia caballi and Theileria equi was determined in a donkey population from Campania Region in Southern Italy using a commercial indirect fluorescent antibody test (IFAT), and the risk factors associated with the occurrence of the infection were assessed.Of 203 samples, the overall seroprevalence for EP was 57.1% (116/203), with 35.5% (72/203) for B. caballi and 44.3% (90/203) for T. equi. Co-infection was detected in 46 donkeys (22.6%). The distribution of IFAT antibody titres to B. caballi was: 1:80 (n = 67), 1:160 (n = 2), 1:320 (n = 3); while the distribution of IFAT antibody titres to T. equi was: 1:80 (n = 25), 1:160 (n = 42), 1:320 (n = 12), 1:640 (n = 8), 1:1280 (n = 3). All examined donkeys were asymptomatic, except one adult male (with a titre of 1:640 against T. equi) that showed clinical signs corresponding to the acute stage of EP, reported for the first time in Italy.The unique risk factor associated with a higher B. caballi seroprevalence was the presence of horses in the farms, while risk factors associated with a higher T. equi seroprevalence were poor body condition, presence of ruminants in the farms and milk production. The results indicate a high level of exposure in donkeys living in Southern Italy and suggest that donkeys may be an important reservoir of EP.