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Whole genome sequences (WGS) of 185 North American Thoroughbred horses were compared to quantify the number and frequency of variants, diversity of mitotypes, and autosomal runs of homozygosity (ROH). Of the samples, 82 horses were born between 1965 and 1986 (Group 1); the remaining 103, selected to maximize pedigree diversity, were born between 2000 and 2020 (Group 2). Over 14.3 million autosomal variants were identified with 4.5-5.0 million found per horse. Mitochondrial sequences associated the North American Thoroughbreds with 9 of 17 clades previously identified among diverse breeds. Individual coefficients of inbreeding, estimated from ROH, averaged 0.266 (Group 1) and 0.283 (Group 2). When SNP arrays were simulated using subsets of WGS markers, the arrays over-estimated lengths of ROH. WGS-based estimates of inbreeding were highly correlated (r > 0.98) with SNP array-based estimates, but only moderately correlated (r = 0.40) with inbreeding based on 5-generation pedigrees. On average, Group 1 horses had more heterozygous variants (P

Simple Summary: Herds of free-roaming, unowned horses can grow rapidly on rangelands with limited resources. Contraception can offer a humane, publicly acceptable method for slowing or stopping horse population growth and protecting the range. The best-tested and most widely used contraceptive for wild horses, porcine zona pellucida (PZP), a protein-based vaccine, has successfully stabilized or reduced free-roaming horse herds in different environments. While extensive research has shown that the PZP vaccine is safe, concerns still exist about its possible effects on the behavior and well-being of treated mares, and especially the survival of their offspring. Reporting the results of an eight-year study of PZP contraception in wild horses at two sites in the western USA, we show here that mares without foals improved the body condition faster than mares with foals. We also found that the foaling seasons of the PZP-treated herds were later in the year and more spread out. However, deaths of the foals born to PZP-treated mares through their second year of life were very rare and no more frequent than those of foals born to untreated mares. Thus, at our study sites, the timing of breeding was changed by PZP treatments, but we found no evidence that these changes were harmful either to the treated mares or their foals. Wildlife managers and the public have expressed considerable interest in the use of contraception to help manage the populations of wild horses and burros (Equus caballus and E. asinus). Field testing has shown that two preparations of the porcine zona pellucida (PZP) vaccine, a simple emulsion (ZonaStat-H) and PZP-22 (which supplements ZonaStat-H with a controlled-release component) effectively prevent pregnancy in individual mares and can substantially reduce population foaling rates. To determine whether some PZP preparations might have secondary effects that harm treated mares or their foals, we examined the effects of PZP-22 vaccinations and the follow-up boosters of either PZP-22 or ZonaStat-H on adult female body condition, foaling season, and foal mortality in two wild horse herds in the western USA, Cedar Mountains Herd Management Area, Utah (CM; 2008–2015), and Sand Wash Basin Herd Management Area, Colorado (SWB; 2008–2014). At both sites in every study year, summer body condition scores improved faster in mares without foals than mares with foals (p < 0.001; CM, n = 234; SWB, n = 172), but PZP treatments did not affect mare body condition apart from their contraceptive effects. Births to mares treated with PZP within the previous three years were delayed and spread out over the foaling season, but foal mortality rates through the first and second year were low, unrelated to date of birth, and virtually identical for the foals of PZP-treated and untreated mothers (all comparisons n.s.; CM, n = 775, SWB, n = 640). Thus, in these two populations, we found no evidence that changes in reproductive timing associated with PZP treatments were harmful to either mares or foals. [ABSTRACT FROM AUTHOR]

Objectives We performed a retrospective analysis of MRSA isolates collected at the university equine clinic including clinical isolates from 2008 to 2021 and screening environmental, equine and personnel isolates from 2016. Methods Screening and clinical samples were cultured on Brilliance MRSA 2 and Columbia agar (Oxoid), respectively, with enrichment for environmental samples. Antimicrobial susceptibility was assessed by disc diffusion. All the isolates were characterized by spa typing. Eighteen selected isolates were subjected to WGS with subsequent wgMLST clonal analysis. Results Among 75 MRSA isolates, five spa types were identified, the majority (n  = 67; 89.33%) was t011. All isolates were resistant to cefoxitin and ampicillin and carried the mecA gene. In addition, the isolates were resistant to tetracycline (n  = 74; 98.67%), gentamicin (n  = 70; 93.33%), enrofloxacin (n  = 54; 72.00%), sulfamethoxazole-trimethoprim (n  = 5; 6.67%) and lincomycin (n  = 3; 4.00%) with corresponding genetic markers for the resistance detected in the sequenced isolates. All 18 sequenced isolates belonged to ST398, 16 carried SCC mec type IVa and two carried SCC mec type Vc (5C2&5). Further, isolates carried aur , hlgA , hlgB and hlgC virulence genes, and five isolates carried sak and scn genes, which are part of the immune evasion cluster. Close genetic relatedness was found between isolates from the staff of the clinic and clinical samples of horses. Conclusions Repeated introduction and long-term persistence of the equine LA-MRSA subclone (ST398-MRSA-IVa/Vc(5C2&5), t011) among the infected horses at the equine clinic with the colonization of personnel, and the environment contamination that might contribute to transmission were observed. [ABSTRACT FROM AUTHOR]

Since the passage of the Wild Free‐Roaming Horses and Burros Act of 1971, federal agencies have been responsible for managing free‐roaming equids in the United States. Over the last 20 years, management has been hampered by direct opposition from advocacy groups, budget limitations, and a decline in the public's willingness to adopt free‐roaming horses (Equus caballus). As a result, free‐roaming equid numbers have increased to >3 times the targeted goal of 26,785 (horses and burros [E. asinus] combined), the cumulative sum of the appropriate management levels (AML) for all 177 designated herd management areas (HMA) managed by the Bureau of Land Management. This increase is one of the causes of greater sage‐grouse (Centrocercus urophasianus) population declines, owing to habitat alteration from free‐roaming equids exacerbated by ongoing drought. To evaluate potential demographic mechanisms influencing these declines, we compiled survival data from 4 studies in central Wyoming, USA, including 995 adult female (first‐year breeders or older) sage‐grouse during the breeding season, 1,075 nests, 372 broods, and 136 juveniles (i.e., overwinter survival for fledged young), from 2008–2022. During this period, we also obtained population information for free‐roaming horses from 9 HMAs used by individual grouse in our sample. Population estimates of free‐roaming horses for these HMAs ranged from 59% to 7 times of the maximum appropriate management level (AMLmax). Sage‐grouse monitored outside of HMAs represented control populations and, because we assumed they were not exposed to populations of free‐roaming horses, we set values of AMLmax to zero for all grouse located outside of HMAs. To evaluate whether free‐roaming horses were negatively affecting sage‐grouse, we modeled daily survival of breeding age females, nest, broods, and juveniles. There was strong or moderate evidence that overabundant free‐roaming horses negatively affected nest, brood, and juvenile survival. When horse abundance increased from AMLmax to 3 times AMLmax, survival was reduced 8.1%, 18.3%, 18.2%, and 18.2% for nests, early broods (≤20 days after hatch), late broods (>20 days to 35 days after hatch), and juveniles, respectively. These results indicate increasing free‐roaming horse numbers affected vital rates for important life stages of sage‐grouse, and that maintaining free‐roaming horse numbers below AMLmax would reduce negative effects to sage‐grouse populations. [ABSTRACT FROM AUTHOR]

Horsemeat consumption has been one of the most intriguing questions about ancient dietary practices. Zooarchaeological materials from the Late Bronze Age in Estonia (850â500 BCE) contain high proportions of the domestic horse (Equus caballus) compared to subsequent periods, leading to debates about the cultural­-economic features of eating horsemeat during this period. One of the assemblages rich in horse remains is from the Iru fortified settlement in northern Estonia, first studied by Kalju Paaver in the 1960s. This article revisits the Iru zooarchaeological material with the aim of clarifying the significance of horsemeat con sumption among Iru people and expanding the discussion about the Bronze Age horse culture in prehistoric Estonia. Several findings confirmed the consumption of horsemeat. First, the taxonomic analysis showed a high proportion of horse specimens among livestock remains, contextually interpreted as kitchen and food refuse. Second, despite the horse specimens coming mainly from the cranium (teeth) and body parts with low meat yield (distal elements of the limbs), the evidence of butchering, especially for elements representing meaty body parts, attests to various food procurement activities. Third, the presence of juvenile specimens in the material refers to the culling of young animals, even though there is no direct evidence of utilising juvenile meat. The study results are discussed in the frame of contemporaneous material from Estonia and elsewhere, touching upon the extent of horsemeat consumption, the tools used for butchering, and the possible origins of the Bronze Age horse culture in Estonia.

Abstract Whole genome sequences (WGS) of 185 North American Thoroughbred horses were compared to quantify the number and frequency of variants, diversity of mitotypes, and autosomal runs of homozygosity (ROH). Of the samples, 82 horses were born between 1965 and 1986 (Group 1); the remaining 103, selected to maximize pedigree diversity, were born between 2000 and 2020 (Group 2). Over 14.3 million autosomal variants were identified with 4.5–5.0 million found per horse. Mitochondrial sequences associated the North American Thoroughbreds with 9 of 17 clades previously identified among diverse breeds. Individual coefficients of inbreeding, estimated from ROH, averaged 0.266 (Group 1) and 0.283 (Group 2). When SNP arrays were simulated using subsets of WGS markers, the arrays over-estimated lengths of ROH. WGS-based estimates of inbreeding were highly correlated (r > 0.98) with SNP array-based estimates, but only moderately correlated (r = 0.40) with inbreeding based on 5-generation pedigrees. On average, Group 1 horses had more heterozygous variants (P

Background The veterinary workplace carries a high risk of staff accidents and injuries, yet there is scant research exploring it in comparison with other comparable fields, such as human medicine. Aims To understand how veterinary professionals define injuries and to understand what injuries they do, or do not, deem reportable. Methods A cross-sectional survey comprising demographic questions and open-text questions was shared with veterinary practice staff across the UK. Data were analysed descriptively and using an inductive content analysis. Results There were 740 respondents, who were broadly representative of the veterinary profession. There were differences in how injuries were defined; for example, small animal veterinarians expected injuries to involve blood, while equine and production animal veterinarians were more likely to expect injuries to reduce their ability to perform work and require medical treatment. Many suggested that 'all' workplace injuries should be reported; however, 'minor' injuries were often overlooked, for example, needlestick injuries did not always meet the criteria of being an 'injury'. Injuries caused by staff themselves (e.g. trips) were less likely to be reported than injuries that could be blamed on an external factor (e.g. dog bite). Conclusions Collectively, the data suggest a wide-ranging perception of risk of injury in practice, with some harms seen as 'everyday norms'. Veterinary practices should interpret their injury statistics with a high degree of caution. They should explore the microcultures within their practices relating to worker perception of risk, injury and barriers to reporting. [ABSTRACT FROM AUTHOR]

Depredation of domestic horses (Equus caballus) by jaguars (Panthera onca) is an example of human–wildlife conflict that has not received much attention. We monitored spatio‐temporal activity and distribution of horses in a 2.64‐km2 fenced area in the dry forest of northwestern Costa Rica in response to 16 jaguar killings of horses during January‐November 2017. We monitored 4 horses (2 males, 2 females) equipped with global positioning system transmitters from February‐September 2018 to identify daily and seasonal patterns of use of cover types and a water source by horses. We then compared these results to the previous locations where jaguars killed horses to identify the circumstances under which horses seemed more vulnerable to jaguar predation. Based on 1,693 locations, horses spent most time in grassland (92%) rather than forest and edge vegetation (8%) and used a core area of 0.74 km2 (kernel density estimation) to 0.86 km2 (minimum convex polygon). Of 16 horse predation events by jaguars, 9 events (56%) occurred in grasslands, 4 in forested areas (25%), and 3 in the forest edge (19%), indicating predation events occurred disproportionately from expected counts based on horse use of vegetation. The predation sites were characterized by a higher proportion of edge and a lower proportion of forest compared to a random points. We suggest that when horses explored areas near the edge of forested areas, the chances of being preyed on by jaguars increased. [ABSTRACT FROM AUTHOR]

Horses are animals traditionally playing prominent role as both food source and working animals for Kazakh people. Zhabe horses are traditional type of indigenous Kazakh horses characterized by versatility and adaptation to conditions of Central Asia. The present work focuses on examination of genetic structure of Zhabe horses using SNP genotyping with addition of previously published data. Total 1038 individuals including 403 new samples of Zhabe horses and 42 sample of white horses ‘Zhetysu Asyly’ have been considered. DNA was extracted from hair roots using commercial DNA isolation kit and further used for analysis of SNP by Illumina iScan system with Equine80k SNP array. The analysis of population genetic parameters (expected and observed heterozygosity, linkage disequilibrium, Wright's Fst) and genetic structure (PCA, ADMIXTURE) in comparison with publicly available data on selected foreign cultivars demonstrated low between population differentiations and lack of selection factors. Genome wide association study performed for body size and weight have revealed low occurrence of SNPs with significant associations, total 57 SNPs linked to various genes with low density across all genome. The obtained results highlight difference between traditional horse breeding practices of Kazakh people and stable based breeding of foreign breeds. In contrast, the ‘Zhetysu Asyly’ horse breed derived from Kazakh horses demonstrate the effect of intense breeding process on the same landrace. The results provide new data on the traditional Kazakh horses of type Zhabe and will assist further studies of this original landrace.

Basic methods of population genetics and animal breeding and mathematical methods of machine learning used in animal breeding are analyzed. CatBoost library models were trained on the example of two domesticated species—horse (Equus caballus) and reindeer (Rangifer tarandus). Data from microsatellite panels of loci 16 and 17, respectively, were used to train the model using data on domesticated and wild reindeer, European and Russian horse breeds. The standard indicators (Accuracy, Precision, Recall, and F1) were calculated, and confusion matrices were constructed to assess the success of the model. New possibilities for identifying animal breed affiliation are shown. [ABSTRACT FROM AUTHOR]

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Non‐native species can affect ecosystems by influencing native predator‐prey dynamics. Therefore, management interventions designed to remove non‐natives may inadvertently lead to increased predation on native species. Feral horses are widely distributed throughout the arid parts of western North America. A growing body of research indicates that horses can be an important prey species to mountain lions in ecosystems where they overlap. In December 2020, the Bureau of Land Management removed 455 horses from the Delamar Mountains, Nevada, USA. We leveraged this management intervention to implement a before–after–control–impact study to test hypotheses about predation on horses and native ungulates. We predicted (1) that horses would comprise an important part of the diet in this mixed‐prey community, (2) following removal, the proportion of horses in the diet would decrease and native ungulates would increase, and (3) mountain lion home ranges overlapping the treatment areas would increase in response to decreased prey availability. From 2018 to 2022, we investigated 1360 clusters from 29 GPS‐collared lions and identified 1056 prey items. To model the probability of a predation event (a kill), we fit a mixed‐effects logistic regression model for ungulate prey as a function of lion sex, treatment area (in/out), and treatment period (pre‐/post‐removal). We used a log‐linear regression model to evaluate changes in home range size. The most common prey were mule deer (55%), feral horses (32%), and coyotes (4%). Twenty‐two of 29 lions consumed horses, although the rate of horse consumption was highly variable across individuals. Horses of both sexes and all age classes were predated. In contrast to predictions, our models detected no effect of removals on diet composition (βinteraction = 0.30 ± 1.1), nor did the removal influence home range size (βinteraction = 0.02 ± 0.02). Despite a 46% reduction in horse abundance, we found no evidence for prey‐switching following the horse removal treatment. Removal magnitude, rapid horse immigration, and/or behavioral specialization of individual mountain lions may help explain these results. Our findings have important implications for mountain lion and feral horse management in arid environments characterized by high prey diversity, but low prey abundance. [ABSTRACT FROM AUTHOR]

Background Bacterial contamination of implants has been linked to biofilm formation and subsequent infection, capsular contracture, and breast implant–associated anaplastic large cell lymphoma. Reducing contamination during implant insertion should therefore reduce biofilm formation disease sequelae. Objectives The aim of this study was to compare levels of contamination between preventative techniques. Methods A model to simulate the passage of implants through a skin incision was designed that utilized a sterile textured polyvinyl plastic sheet contaminated with Staphylococcus epidermidis. In the first stage of the polyvinyl contamination model, implants were subject to infection-mitigation techniques and passed through the incision, then placed onto horse blood agar plates and incubated for 24 hours. In the second stage of the study the same contamination was applied to human abdominal wall specimens. A 5 cm incision was made through skin and fat, then implants were passed through and levels of contamination were measured as described. Results Smooth implants grew a mean of 95 colony-forming units (CFUs; approximately 1 CFU/cm2) and textured implants grew 86 CFUs (also approximately 1 CFU/cm2). CFU counts were analyzed by the Mann-Whitney U -test which showed no significant difference between implant types (P <.05); independent-sample t -tests showed a significant difference. The dependent-variable techniques were then compared as groups by one-way analysis of variance, which also showed a significant reduction compared with the control group (P <.01). Conclusions This in vitro study has shown the effectiveness of antiseptic rinse and skin/implant barrier techniques for reducing bacterial contamination of breast implants at the time of insertion. [ABSTRACT FROM AUTHOR]

Equid herpesvirus 4 (EHV-4) is a common respiratory pathogen in horses. It sporadically induces abortion or neonatal death. Although its contribution in neurological disorders is not clearly demonstrated, there is a strong suspicion of its involvement. Despite preventive treatments using vaccines against EHV-1/EHV-4, the resurgence of alpha-EHV infection still constitutes an important threat to the horse industry. Yet very few studies have been conducted on the search for antiviral molecules against EHV-4. A screening of 42 antiviral compounds was performed in vitro on equine fibroblast cells infected with the EHV-4 405/76 reference strain (VR2230). The formation of cytopathic effects was monitored by real-time cell analysis (RTCA), and the viral load was quantified by quantitative PCR. Aciclovir, the most widely used antiviral against alpha-herpesviruses in vivo, does not appear to be effective against EHV-4 in vitro. Potential antiviral activities were confirmed for eight molecules (idoxuridine, vidarabine, pritelivir, cidofovir, valganciclovir, ganciclovir, aphidicolin, and decitabine). Decitabine demonstrates the highest efficacy against EHV-4 in vitro. Transcriptomic analysis revealed the up-regulation of various genes implicated in interferon (IFN) response, suggesting that decitabine triggers the immune antiviral pathway. [ABSTRACT FROM AUTHOR]

Wildlife managers and the public have expressed considerable interest in the use of contraception to help manage the populations of wild horses and burros (Equus caballus and E. asinus). Field testing has shown that two preparations of the porcine zona pellucida (PZP) vaccine, a simple emulsion (ZonaStat-H) and PZP-22 (which supplements ZonaStat-H with a controlled-release component) effectively prevent pregnancy in individual mares and can substantially reduce population foaling rates. To determine whether some PZP preparations might have secondary effects that harm treated mares or their foals, we examined the effects of PZP-22 vaccinations and the follow-up boosters of either PZP-22 or ZonaStat-H on adult female body condition, foaling season, and foal mortality in two wild horse herds in the western USA, Cedar Mountains Herd Management Area, Utah (CM; 2008–2015), and Sand Wash Basin Herd Management Area, Colorado (SWB; 2008–2014). At both sites in every study year, summer body condition scores improved faster in mares without foals than mares with foals (p < 0.001; CM, n = 234; SWB, n = 172), but PZP treatments did not affect mare body condition apart from their contraceptive effects. Births to mares treated with PZP within the previous three years were delayed and spread out over the foaling season, but foal mortality rates through the first and second year were low, unrelated to date of birth, and virtually identical for the foals of PZP-treated and untreated mothers (all comparisons n.s.; CM, n = 775, SWB, n = 640). Thus, in these two populations, we found no evidence that changes in reproductive timing associated with PZP treatments were harmful to either mares or foals.

Open in new tab Download slide OBJECTIVES The goal of this histological study was to assess the biocompatibility of vascular patches used in the repair of congenital heart defects. METHODS We examined tissue-engineered bovine (n = 7) and equine (n = 7) patches and autologous human pericardium (n = 7), all explanted due to functional issues or follow-up procedures. Techniques like Movat-Verhoeff, von Kossa and immunohistochemical staining were used to analyse tissue composition, detect calcifications and identify immune cells. A semi-quantitative scoring system was implemented to evaluate the biocompatibility aspects, thrombus formation, extent of pannus, inflammation of pannus, cellular response to patch material, patch degradation, calcification and neoadventitial inflammation. RESULTS We observed distinct material degradation patterns among types of patches. Bovine patches showed collagen disintegration and exudate accumulation, whereas equine patches displayed edematous swelling and material dissolution. Biocompatibility scores were lower in terms of cellular response, degradation and overall score for human autologous pericardial patches compared to tissue-engineered types. The extent of pannus formation was not influenced by the type of patch. Bovine patches had notable calcifications causing tissue hardening, and foreign body giant cells were more frequently seen in equine patches. Plasma cells were frequently detected in the neointimal tissue of engineered patches. CONCLUSIONS Our results confirm the superior biocompatibility of human autologous patches and highlight discernible variations in the changes of patch material and the cellular response to patch material between bovine and equine patches. Our approach implements the semi-quantitative scoring of various aspects of biocompatibility, facilitating a comparative quantitative analysis across all types of patches, despite their inherent differences. [ABSTRACT FROM AUTHOR]

This comprehensive review analyzes the state of horse breeding in Kazakhstan, examining its historical context, current status, genetic studies, and future prospects. Drawing on historical records, government reports, academic studies, and genetic research, this review provides insights into the genetic diversity of Kazakh native horse breeds. The review traces the historical trajectory of horse breeding, explores its significance for the economy and culture, and discusses current population trends. Genetic studies reveal untapped potential for breed improvement. Kazakhstan's horse breeding faces opportunities for growth and development, requiring efforts to increase the horse population and harness genetic potential for productivity. This review emphasizes the need to preserve the gene pool of Kazakh native horses, ensuring sustainability and cultural significance. [ABSTRACT FROM AUTHOR]

Abstract Non‐native species can affect ecosystems by influencing native predator‐prey dynamics. Therefore, management interventions designed to remove non‐natives may inadvertently lead to increased predation on native species. Feral horses are widely distributed throughout the arid parts of western North America. A growing body of research indicates that horses can be an important prey species to mountain lions in ecosystems where they overlap. In December 2020, the Bureau of Land Management removed 455 horses from the Delamar Mountains, Nevada, USA. We leveraged this management intervention to implement a before–after–control–impact study to test hypotheses about predation on horses and native ungulates. We predicted (1) that horses would comprise an important part of the diet in this mixed‐prey community, (2) following removal, the proportion of horses in the diet would decrease and native ungulates would increase, and (3) mountain lion home ranges overlapping the treatment areas would increase in response to decreased prey availability. From 2018 to 2022, we investigated 1360 clusters from 29 GPS‐collared lions and identified 1056 prey items. To model the probability of a predation event (a kill), we fit a mixed‐effects logistic regression model for ungulate prey as a function of lion sex, treatment area (in/out), and treatment period (pre‐/post‐removal). We used a log‐linear regression model to evaluate changes in home range size. The most common prey were mule deer (55%), feral horses (32%), and coyotes (4%). Twenty‐two of 29 lions consumed horses, although the rate of horse consumption was highly variable across individuals. Horses of both sexes and all age classes were predated. In contrast to predictions, our models detected no effect of removals on diet composition (βinteraction = 0.30 ± 1.1), nor did the removal influence home range size (βinteraction = 0.02 ± 0.02). Despite a 46% reduction in horse abundance, we found no evidence for prey‐switching following the horse removal treatment. Removal magnitude, rapid horse immigration, and/or behavioral specialization of individual mountain lions may help explain these results. Our findings have important implications for mountain lion and feral horse management in arid environments characterized by high prey diversity, but low prey abundance.

This paper examines the species composition of endobiotic ciliates in the faecal samples from domestic Marwari horses (Equus caballus) from the Thar Desert, Rajasthan, India. We discovered nine species of ciliates from the Cycloposthiidae, Buetschliidae, Blepharocorythidae, Spirodiniidae, and Paraisotrichidae families. We also emphasise that Marwari horses differ considerably from domestic horses in other geographical regions by the species composition of endobiotic ciliates. We assume that such difference may be due to their diet, which is largely based on peanut roughage.

Context. Mule deer (Odocoileus hemionus) are a species of social, economic and cultural importance that are experiencing a population decline throughout much of their range. Factors such as disease, landscape-level changes in nutritional output of forage species, winter habitat degradation, habitat fragmentation, competition for resources with both domestic and wild ungulates, and predation have all been implicated in the decline. Recently, summer habitat quality in Oregon has been identified as a potentially strong limiting factor for mule deer population performance. Competition and habitat degradation from feral horses (Equus caballus) have been proposed as factors potentially exacerbating existing habitat limitations for mule deer. Aims. The aim of this study was to investigate factors affecting mule deer summer range occupancy within a study area that experienced both wildfires and the presence of feral horses. Methods. We deployed 72, 77 and 75 camera traps throughout the Murderers Creek and Northside wildlife management units located in north-eastern Oregon during summer 2019, 2020 and 2021 respectively. We used an occupancy modelling framework to build and evaluate models of mule deer summer range occupancy related to competition, vegetation and abiotic variables. Key results. Our final model set included four covariates: (1) an index of feral horse use; (2) whether the site was disturbed by wildfire; (3) distance to forest edge; and (4) eastness of the site. Model averaging indicated that mule deer probability of occupancy was negatively related with increased feral horse use and distance to forest edge, and positively related to eastern slopes and sites within a wildfire perimeter. Conclusions. Our results add to the growing body of literature indicating that wildfires in forested ecosystems benefit mule deer and add to the limited body of literature indicating that feral horse use of a site negatively impacts mule deer. Implications. Managers should incorporate fire into forest restoration projects when possible to benefit mule deer. Where feral horses and mule deer overlap, increased management of feral horse herds could potentially benefit mule deer. Lastly, our research showcases the utility of camera traps coupled with occupancy modelling to answer research questions that, in the past, were mainly answered through radio collaring. [ABSTRACT FROM AUTHOR]

Horses were domesticated later than other farm animals. Horse breeds have been selectively developed by humans to satisfy different needs and purposes. The factory and indigenous breeds are of particular interest, having been bred in purity for many centuries without the addition of foreign blood. Data from 31 stud farms, as well as ranches, located in fifteen regions of the Russian Federation were used in this work. DNA was sampled from 102 stallions of 11 breeds: Arabian, Akhal-Teke, Don, Orlov Trotter, Vladimir Heavy Draft, Russian Heavy Draft, Soviet Heavy Draft, Kabardin, Yakut, Tuva, and Vyatka. Data on the origin of each animal from which the material was collected were taken into account. DNA genotyping was carried out using GGP Equine 70 k ® array chips (Thermo Fisher Scientific, USA). Genetic diversity of horse breeds was estimated using Admixture 1.3. and PLINK 1.9 software. FROH inbreeding was computed via the R detectRUNS package. The minimum length for ROH was set at 1 Mb to reduce the occurrence of false positives. We conducted PCA analysis using PLINK 1.9, and used the ggplot2 library in R for visualizing the results. Indigenous equine breeds, such as Vyatka, Tuva, and Yakut, are very hardy, and well adapted to local environmental and climatic conditions. They are employed as draft power, as well as for milk and meat. Both the Akhal-Teke breed and the Arabian breed have retained a minimum effective population size over many generations. We note significant accumulations of homozygosity in these breeds. In equestrian sports, performance is a top priority. ADMIXTURE and PCA analyses showed similarities between Don equine breeds and Kabardin, as well as some Arabian breed animals. Earlier research indicated the presence of thoroughbred traits in Don stallions. The Orlov Trotter breed stands out as a separate cluster in the structural and PCA analyses. Considering the small population size of this breed, our study found high FROH in all tested animals. The general reduction in the diversity of the horse breed gene pool, due to numerous crosses for breed improvement with thoroughbreds, has lead to a decline in the differences between the top sporting breeds. Our study presents new opportunities for exploring the genetic factors that influence the formation of adaptive traits in indigenous breeds, and for finding ways to preserve genetic diversity for effective population reproduction. [ABSTRACT FROM AUTHOR]

With the advent of genomics, significant progress has been made in the genetic improvement of livestock species, particularly through increased accuracy in predicting breeding values for selecting superior animals and the possibility of performing a high‐resolution genetic scan throughout the genome of an individual. The main objectives of this study were to estimate the individual genomic inbreeding coefficient based on runs of homozygosity (FROH), to identify and characterize runs of homozygosity and heterozygosity (ROH and ROHet, respectively; length and distribution) throughout the genome, and to map selection signatures in relevant chromosomal regions in the Quarter Horse racing line. A total of 336 animals registered with the Brazilian Association of Quarter Horse Breeders (ABQM) were genotyped. One hundred and twelve animals were genotyped using the Equine SNP50 BeadChip (Illumina, USA), with 54,602 single nucleotide polymorphisms (SNPs; 54K). The remaining 224 samples were genotyped using the Equine SNP70 BeadChip (Illumina, USA) with 65,157 SNPs (65K). To ensure data quality, we excluded animals with a call rate below 0.9. We also excluded SNPs located on non‐autosomal chromosomes, as well as those with a call rate below 0.9 or a p‐value below 1 × 10−5 for Hardy–Weinberg equilibrium. The results indicate moderate to high genomic inbreeding, with 46,594 ROH and 16,101 ROHet detected. In total, 30 and 14 candidate genes overlap with ROH and ROHet regions, respectively. The ROH islands showed genes linked to crucial biological processes, such as cell differentiation (CTBP1, WNT5B, and TMEM120B), regulation of glucose metabolic process (MAEA and NKX1‐1), heme transport (PGRMC2), and negative regulation of calcium ion import (VDAC1). In ROHet, the islands showed genes related to respiratory capacity (OR7D19, OR7D4G, OR7D4E, and OR7D4J) and muscle repair (EGFR and BCL9). These findings could aid in selecting animals with greater regenerative capacity and developing treatments for muscle disorders in the QH breed. This study serves as a foundation for future research on equine breeds. It can contribute to developing reproductive strategies in animal breeding programs to improve and preserve the Quarter Horse breed. [ABSTRACT FROM AUTHOR]

Six foals with interstitial pneumonia of undetermined etiology from Southern California were analyzed by viral metagenomics. Spleen, lung, and colon content samples obtained during necropsy from each animal were pooled, and nucleic acids from virus-like particles enriched for deep sequencing. The recently described equine copiparvovirus named eqcopivirus, as well as three previously uncharacterized viruses, were identified. The complete ORFs genomes of two closely related protoparvoviruses, and of a bocaparvovirus, plus the partial genome of a picornavirus were assembled. The parvoviruses were classified as members of new ungulate protoparvovirus and bocaparvovirus species in the Parvoviridae family. The picornavirus was classified as a new species in the Salivirus genus of the Picornaviridae family. Spleen, lung, and colon content samples from each foal were then tested for these viral genomes by nested PCR and RT-PCR. When present, parvoviruses were detected in both feces and spleen. The picornavirus, protoparvovirus, and eqcopivirus genomes were detected in the lungs of one animal each. Three foals were co-infected with the picornavirus and either a protoparvovirus, bocaparvovirus, or eqcopivirus. Two other foals were infected with a protoparvovirus only. No viral infection was detected in one animal. The complete ORFs of the first equine protoparvoviruses and bocaparvovirus, the partial ORF of the third equine picornavirus, and their detection in tissues of foals with interstitial pneumonia are described here. Testing the involvement of these viruses in fatal interstitial pneumonia or other equine diseases will require larger epidemiological and/or inoculation studies.

West Nile virus (WNV) is a re-emerging zoonotic pathogen with increasing incidence in Europe, producing a recent outbreak in 2020 in Spain with 77 human cases and eight fatalities. However, the factors explaining the observed changes in the incidence of WNV in Europe are not completely understood. Longitudinal monitoring of WNV in wild animals across Europe is a useful approach to understand the eco-epidemiology of WNV in the wild and the risk of spillover into humans. However, such studies are very scarce up to now. Here, we analysed the occurrence of WNV and Usutu virus (USUV) antibodies in 2102 samples collected between 2005 and 2020 from a population of feral horses in Doñana National Park. The prevalence of WNV antibodies varied between years, with a mean seroprevalence of 8.1% (range 0%–25%) and seasonally. Climate conditions including mean minimum annual temperatures and mean rainy days per year were positively correlated with WNV seroprevalence, while the annual rainfall was negatively. We also detected the highest incidence of seroconversions in 2020 coinciding with the human outbreak in southern Spain. Usutu virus-specific antibodies were detected in the horse population since 2011. The WNV outbreak in humans was preceded by a long period of increasing circulation of WNV among horses with a very high exposure in the year of the outbreak. These results highlight the utility of One Health approaches to better understand the transmission dynamics of zoonotics pathogens.

Existen varias metodologías para determinar la condición corporal del caballo deportivo, siendo unas más objetivas que otras; sin embargo, la escala de condición corporal es la más usada para estimar las reservas corporales de animales en actividad atlética. El objetivo del estudio fue estimar, por métodos no invasivos, el espesor de grasa subcutánea y desarrollo muscular de caballos deportivos, de una academia de Cundinamarca y calcular algunos índices que definen la composición corporal. Se escogieron 29 caballos adultos (9 hembras, 20 machos), de cuatro tipos raciales; caballo deporte colombiano, criollo, polo argentino, Pura sangre inglés. Para evaluar la grasa subcutánea se usó el puntaje de condición corporal (PCC) escala Henneke, el ultrasonido en tiempo real UTR, midiendo espesor de grasa dorsal y de cadera. La musculatura se determinó usando UTR a nivel dorsal, midiendo el ojo del lomo y el glúteo medio. Se tomaron pesos y medidas morfométricas: altura de cruz, longitud corporal, perímetro torácico. Con estas medidas corporales o ecográficas se calcularon índices de desempeño o composición corporal: índice corporal (IC), índice de carga al paso-1 y al trote-2 (IC1 y IC2), % de grasa corporal (%GC), Índice de masa corporal (IMC), relación perímetro torácico–altura cruz (PT:AC), índice muscular (IM) e índice musculoesquelético (IME). Los índices de carga y de composición corporal indicaron diferencias entre tipos raciales (p

The major histocompatibility complex (MHC) with its class I and II genes plays a crucial role in the immune response to pathogens by presenting oligopeptide antigens to various immune response effector cells. In order to counteract the vast variability of infectious agents, MHC class I and II genes usually retain high levels of SNPs mainly concentrated in the exons encoding the antigen binding sites. The aim of the study was to reveal new variability of selected MHC genes with a special focus on MHC class I physical haplotypes. Long‐range NGS to was used to identify exon 2–exon 3 alleles in three genetically distinct horse breeds. A total of 116 allelic variants were found in the MHC class I genes Eqca‐1, Eqca‐2, Eqca‐7 and Eqca‐Ψ, 112 of which were novel. The MHC class II DRA locus was confirmed to comprise five exon 2 alleles, and no new sequences were observed. Additional variability in terms of 15 novel exon 2 alleles was identified in the DQA1 locus. Extensive overall variability across the entire MHC region was confirmed by an analysis of MHC‐linked microsatellite loci. Both diversifying and purifying selection were detected within the MHC class I and II loci analyzed. [ABSTRACT FROM AUTHOR]

Communication of emotions plays a key role in intraspecific social interactions and likely in interspecific interactions. Several studies have shown that animals perceive human joy and anger, but few studies have examined other human emotions, such as sadness. In this study, we conducted a cross-modal experiment, in which we showed 28 horses two soundless videos simultaneously, one showing a sad, and one a joyful human face. These were accompanied by either a sad or joyful voice. The number of horses whose first look to the video that was incongruent with the voice was longer than their first look to the congruent video was higher than chance, suggesting that horses could form cross-modal representations of human joy and sadness. Moreover, horses were more attentive to the videos of joy and looked at them for longer, more frequently, and more rapidly than the videos of sadness. Their heart rates tended to increase when they heard joy and to decrease when they heard sadness. These results show that horses are able to discriminate facial and vocal expressions of joy and sadness and may form cross-modal representations of these emotions; they also are more attracted to joyful faces than to sad faces and seem to be more aroused by a joyful voice than a sad voice. Further studies are needed to better understand how horses perceive the range of human emotions, and we propose that future experiments include neutral stimuli as well as emotions with different arousal levels but a same valence. [ABSTRACT FROM AUTHOR]

The available science often demonstrates the need for feral horse population control but not the degree of control required to achieve environmental conservation objectives. To better manage the influence of feral horses, we must first understand the relationship between feral horse density and environmental impact. We recorded vegetation and soil disturbance, and the sign of potential causes of this impact in two parts of the Australian Alps, the Bogong high plains (BHP) and the Eastern Victorian Alps (EVA). We calculated density‐impact functions to assist managers with determining feral horse density targets for control programmes. Minimal sign of feral horse impact was detected on the BHP, with no impact of feral horses observed along 99% of the length of transects. In contrast, impacts assigned to feral horses were significantly higher in the EVA, where a larger, higher‐density population of feral horses existed. However, greater than 83% of the walked transect length was still undisturbed by feral horses in the EVA. We detected a threshold of horse impact at ~ 250 horse faecal piles per ha. Above this threshold, a slight increase in horse density resulted in a disproportionately large increase in impact. In this context, a relatively small population control effort may substantially reduce direct horse impact. But where horse densities exist below this threshold, considerably more expense and control effort (resulting from the difficulties related to control at low density) is likely to make very little difference to an already low level of direct impact. The combined impacts associated with the sign of deer, feral pigs, fire and humans were large compared to that of feral horses. Management of feral horses to reduce their direct impact is unlikely to be beneficial without complementary management to reduce the effects of these other agents of impact. [ABSTRACT FROM AUTHOR]

A total of 166 horses of the Russian Riding breed were studied using 17 microsatellite loci recommended by ISAG. Microsatellite polymorphism data of 34 European breeds (7874 individuals) were used for comparative analysis of genetic diversity and modern clustering. The Russian Riding horse has high values of allele richness, 5.4 alleles per microsatellite locus. In total, 122 alleles were found in the breed, including the private allele 14 at the HTG7 locus. The population genetic structure of the Russian riding, Arabian, Akhal-Teke, German riding, and purebred riding breeds has been described. Clustering of horse breeds on a circular UPGMA dendrogram revealed six main clusters. The Russian riding horse grouped with the German and purebred English horses in the PCA analysis. Breeds were divided into three populations in STRUCTURE (K = 3): (1) Arabian, (2) Russian Riding, Akhal-Teke, and Thoroughbred Riding, (3) German Half-Bred. Differentiation analysis between breeds using the Fst method showed the greatest values (differences) between Akhal-Teke horses and all other breeds. The smallest value (Fst = 0.22) between the Russian riding and German riding breed. Pairwise differences between breeds were significant (p-value < 0.001). [ABSTRACT FROM AUTHOR]

Social buffering occurs when a companion helps to reduce a subject's stress response during a stressful event and/or to recover more quickly from a stressful event. The aim of this study was to determine if any social buffering function of a horse companion can occur in relation to a visual substitute (poster of a relaxed horse face) during two different stressful situations: a novel object test (a ball presented gradually) and an umbrella test (sudden opening of an umbrella). In order to evaluate the effect of a horse face poster on the subject's stress responses, behavioral (reactivity score) and physiological (heart rate) measurements were taken. Each of the 28 study subjects completed four trials: two novel object tests and two umbrella tests—each with a relaxed horse face poster and a pixelated poster (control). Our results showed that the presence of a horse face poster might significantly reduce the behavioral response (reactivity) of subject horses in the novel object test but did not improve heart rate recovery (HRR) time. The horse face poster did not have a significant effect on the behavioral reaction or HRR in the umbrella test. Any effect of a horse face poster as a potential social buffer might potentially depend on the nature of the stressful event. • Horses exposed to different physical stressors with a conspecific or control image. • The conspecific image reduced behavioral but not physiological response to the gradual stimulus. • The conspecific image had no significant effect on response to the sudden stimulus • Impact of the conspecific image as a potential social buffer depends on the nature of the stressful event. • Social buffering function of a companion might be at least partially replaced by a visual substitute. [ABSTRACT FROM AUTHOR]

Horses are animals that are affected very quickly by the warnings coming from the environment. In this study, it was aimed to evaluate oxidative stress parameters of horses obtained from saliva analysis related to animal welfare as a result of keeping horses together with goats. While the research was being prepared, three groups were developed based on the time spent sheltering goats and horses. The horses were housed alone in the first and last 15-day groups, and along with the goats in the second 15-day group. In these stages, the levels of malondialdehyde (MDA), catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD) activities and ischemia-modified albumin (IMA) level in saliva were examined. Results showed that MDA and IMA levels decreased, but CAT, GPx, and SOD activities increased. It was concluded that goats had a positive effect on horses according to the oxidative stress parameters examined in terms of animal welfare. However, there is still a need for research that will house horses with various animals in acceptable animal welfare circumstances, analyse their stress metrics, and maintain a high level of welfare. [ABSTRACT FROM AUTHOR]

Feral horse (Equus caballus) population management is a challenging problem around the world because populations often exhibit density‐independent growth, can exert negative ecological effects on ecosystems, and require great cost to be managed. However, strong value‐based connections between people and horses cause contention around management decisions. To help make informed decisions, natural resource managers might benefit from more detailed understanding of how horse management alternatives, including combinations of removals and fertility control methods, could achieve objectives of sustainable, multiple‐use ecosystems while minimizing overall horse handling and fiscal costs. Here, we describe a modeling tool that simulates horse management alternatives and estimates trade‐offs in predicted metrics related to population size, animal handling, and direct costs of management. The model considers six management actions for populations (removals for adoption or long‐term holding; fertility control treatment with three vaccines, intrauterine devices, and mare sterilization), used alone or in combination. We simulated 19 alternative management scenarios at 2‐, 3‐, and 4‐year management return intervals and identified efficiency frontiers among alternatives for trade‐offs between predicted population size and six management metrics. Our analysis identified multiple alternatives that could maintain populations within target population size ranges, but some alternatives (e.g., removal and mare sterilization, removal and GonaCon treatment) performed better at minimizing overall animal handling requirements and management costs. Cost savings increased under alternatives with more effective, longer lasting fertility control techniques over longer management intervals compared with alternatives with less‐effective, shorter lasting fertility control techniques. We built a user‐friendly website application, PopEquus, that decision makers and interested individuals can use to simulate management alternatives and evaluate trade‐offs among management and cost metrics. Our results and website application provide quantitative trade‐off tools for horse population management decisions and can help support value‐based management decisions for wild or feral horse populations and ecosystems at local and regional scales around the world. [ABSTRACT FROM AUTHOR]

The horse, one of the most domesticated animals, has been used for several purposes, like transportation, hunting, in sport, or for agriculture-related works. Kathiawari, Marwari, Manipuri, Zanskari, Bhutia, Spiti, and Thoroughbred are the main breeds of horses, particularly due to their agroclimatic adaptation and role in any kind of strong physical activity, and these characteristics are majorly governed by genetic factors. The genetic diversity and phylogenetic relationship of these Indian equine breeds using microsatellite markers have been reported, but further studies exploring the SNP diversity and runs of homozygosity revealing the selection signature of breeds are still warranted. In our study, the identification of genes that play a vital role in muscle development is performed through SNP detection via the whole-genome sequencing approach. A total of 96 samples, categorized under seven breeds, and 620,721 SNPs were considered to ascertain the ROH patterns amongst all the seven breeds. Over 5444 ROH islands were mined, and the maximum number of ROHs was found to be present in Zanskari, while Thoroughbred was confined to the lowest number of ROHs. Gene enrichment of these ROH islands produced 6757 functional genes, with AGPAT1, CLEC4, and CFAP20 as important gene families. However, QTL annotation revealed that the maximum QTLs were associated with Wither's height trait ontology that falls under the growth trait in all seven breeds. An Equine SNP marker database (EqSNPDb) was developed to catalogue ROHs for all these equine breeds for the flexible and easy chromosome-wise retrieval of ROH along with the genotype details of all the SNPs. Such a study can reveal breed divergence in different climatic and ecological conditions. [ABSTRACT FROM AUTHOR]

The burgeoning population of feral horses in the American west is due to high population growth, resulting from low adult mortality and high foal survival. In two populations of feral horses in western Utah, USA only 15 foals died (5%; mean age <1 month) over a 4-year period. Seven additional foals (age <70 days) were observed separated from their dam, with no return to suckling or associating with the dam (i.e., abandoned). Factors affecting fate of foals were examined by comparing dead and separated foals with siblings (n = 19 dams, n = 32 siblings). Foals becoming separated or dying were observed in all years of the study, were unrelated to horse density, environmental effects, or gather events. There was no effect of dam body condition, parity, or age on foal survival or separation, and no effect of length of time the dam was in a group, whether the foal was born into the same group as conceived, and number of group changes made by the dam while pregnant. Dams of foals that died or were separated were more likely to change groups within 2 months after the foal was first seen, mostly after foal death or separation. Separated foals were near their dam less often, but there was no difference in frequency of social interactions. Separation of foals and dams is a natural occurrence in feral horses and survival likelihood for these foals is high – all separated foals that remained on the range in this study survived. • Factors affecting mortality and abandonment of young feral horse foals were examined. • Out of 288 foals born between 2017 and 2020, 15 died and 7 became separated from their mothers but survived. • There was no effect of mother experience on foal fate. • There was no difference in frequency of nursing, agonistic, or affiliative interactions between foal fates. • Foals that were less often in proximity to their mothers were more likely to be separated. [ABSTRACT FROM AUTHOR]

Abstract During initial maternal recognition of pregnancy (MRP), the equine embryo displays a series of unique events characterized by rapid blastocyst expansion, secretion of a diverse array of molecules, and transuterine migration to interact with the uterine surface. Up to date, the intricate transcriptome and proteome changes of the embryo underlying these events have not been critically studied in horses. Thus, the objective of this study was to perform an integrative transcriptomic (including mRNA, miRNAs, and other small non‐coding RNAs) and proteomic analysis of embryos collected from days 10 to 13 of gestation. The results revealed dynamic transcriptome profiles with a total of 1311 differentially expressed genes, including 18 microRNAs (miRNAs). Two main profiles for mRNAs and miRNAs were identified, one with higher expression in embryos ≤5 mm and the second with higher expression in embryos ≥7 mm. At the protein level, similar results were obtained, with 259 differentially abundant proteins between small and large embryos. Overall, the findings demonstrated fine‐tuned transcriptomic and proteomic regulations in the developing embryo associated with embryo growth. The identification of specific regulation of mRNAs, proteins, and miRNAs on days 12 and 13 of gestation suggested these molecules as pivotal for embryo development and as involved in MRP, and in establishment of pregnancy in general. In addition, the results revealed new insights into prostaglandin synthesis by the equine embryo, miRNAs and genes potentially involved in modulation of the maternal immune response, regulation of endometrial receptivity and of late implantation in the mare.

Cues such as the human pointing gesture, gaze or proximity to an object are widely used in behavioural studies to evaluate animals' abilities to follow human-given cues. Many domestic mammals, such as horses, can follow human cues; however, factors influencing their responses are still unclear. We assessed the performance of 57 horses at a two-way choice task testing their ability to follow cues of either a familiar (N = 28) or an unfamiliar informant (N = 29). We investigated the effects of the length of the relationship between the horse and a familiar person (main caregiver), their social environment (living alone, in dyads, or in groups) and their physical environment (living in stalls/paddocks, alternating between paddocks and pastures, or living full time in pastures). We also controlled for the effects of horses' age and sex. Our results showed that horses' success rate at the task was not affected by the familiarity of the informant and did not improve with the relationship length with the familiar informant but did increase with the age of the horses. Horses living in groups had better success than the ones kept either in dyads or alone. Finally, horses housed in small paddocks had lower success than those living on pasture. These results indicate that with age, horses get better at following human-given indications regardless of who the human informant is and that an appropriate living and social environment could contribute to the development of socio-cognitive skills towards humans. Therefore, such aspects should be considered in studies evaluating animal behaviour. [ABSTRACT FROM AUTHOR]

Simple Summary: Detection and genotyping of genetic variants across genomes has several applications that include, e.g., identification of genetic background of phenotypic traits, detection of disease-related variation, and analysis of population genetic structure. In this study, we attempt to develop a Nanopore sequencing-based genotyping strategy (with MinION system from Oxford Nanopore) that allows simple and cost-efficient genome-wide analysis in horse species. With this method, we generated 28,426 polymorphisms that were genotyped with high accuracy, with a level of error not exceeding 3%. The method can be further improved to increase the number of detected variants and improve their reliability by increasing the sequencing depth. 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 fragments using a modified DOP-PCR and sequenced the resulting products using the MinION system. After initial filtering, this generated 28,426 polymorphisms, which were validated at a 3% error rate. Upon further filtering for polymorphism and reproducibility, we identified 9495 SNPs that reflected the horse population structure. To conclude, the use of nanopore sequencing, in conjunction with a genome enrichment step, is a promising tool that can be practical in a variety of applications, including genotyping, population genomics, association studies, linkage mapping, and potentially genomic selection. [ABSTRACT FROM AUTHOR]

The specifics of breeding and selection significantly affect genetic diversity and variability within a breed. We present the data obtained from the genetic analysis of 21 thoroughbred and warmblood horse breeds. The most detailed information is described from the following breeds: Arabian, Trakehner, French Trotter, Standardbred, and Soviet Heavy Horse. The analysis of 509,617 SNP variants in 87 stallions from 21 populations made it possible to estimate the genetic diversity at the genome-wide level and distinguish the studied horse breeds from each other. In this study, we searched for heterozygous and homozygous ROH regions, evaluated inbreeding using FROH analysis, and generated a population structure using Admixture 1.3 software. Our findings indicate that the Arabian breed is an ancestor of many horse breeds. The study of the full-genome architectonics of breeds is of great practical importance for preserving the genetic characteristics of breeds and managing breeding. Studies were carried out to determine homozygous regions in individual breeds and search for candidate genes in these regions. Fifty-six candidate genes for the influence of selection pressure were identified. Our research reveals genetic diversity consistent with breeding directions and the breeds' history of origin. [ABSTRACT FROM AUTHOR]

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Abstract Feral horse (Equus caballus) population management is a challenging problem around the world because populations often exhibit density‐independent growth, can exert negative ecological effects on ecosystems, and require great cost to be managed. However, strong value‐based connections between people and horses cause contention around management decisions. To help make informed decisions, natural resource managers might benefit from more detailed understanding of how horse management alternatives, including combinations of removals and fertility control methods, could achieve objectives of sustainable, multiple‐use ecosystems while minimizing overall horse handling and fiscal costs. Here, we describe a modeling tool that simulates horse management alternatives and estimates trade‐offs in predicted metrics related to population size, animal handling, and direct costs of management. The model considers six management actions for populations (removals for adoption or long‐term holding; fertility control treatment with three vaccines, intrauterine devices, and mare sterilization), used alone or in combination. We simulated 19 alternative management scenarios at 2‐, 3‐, and 4‐year management return intervals and identified efficiency frontiers among alternatives for trade‐offs between predicted population size and six management metrics. Our analysis identified multiple alternatives that could maintain populations within target population size ranges, but some alternatives (e.g., removal and mare sterilization, removal and GonaCon treatment) performed better at minimizing overall animal handling requirements and management costs. Cost savings increased under alternatives with more effective, longer lasting fertility control techniques over longer management intervals compared with alternatives with less‐effective, shorter lasting fertility control techniques. We built a user‐friendly website application, PopEquus, that decision makers and interested individuals can use to simulate management alternatives and evaluate trade‐offs among management and cost metrics. Our results and website application provide quantitative trade‐off tools for horse population management decisions and can help support value‐based management decisions for wild or feral horse populations and ecosystems at local and regional scales around the world.

Horses are traditionally used in Kazakhstan as a source of food and as working and saddle animals as well. Here, for the first time, microarray-based medium-density single nucleotide polymorphism (SNP) genotyping of six traditionally defined types and breeds of indigenous Kazakh horses was conducted to reveal their genetic structure and find markers associated with animal size and weight. The results showed that the predefined separation between breeds and sampled populations was not supported by the molecular data. The lack of genetic variation between breeds and populations was revealed by the principal component analysis, ADMIXTURE, and distance-based analyses, as well as the general population parameters expected and observed heterozygosity (He and Ho) and between-group fixation index (Fst). The analysis revealed that the studied types and breeds should be considered as a single breed, namely the ‘Kazakh horse’. The comparison with previously published data on global horse breed diversity revealed the relatively high level of individual diversity of Kazakh horses in comparison with the well-known foreign breeds. The Mongolian and Tuva breeds were identified as the closest horse landraces, demonstrating similar patterns of internal variability. The genome-wide association analysis was performed for animal size and weight as the traits directly related with the meat productivity of horses. The analysis identified a set of 60 SNPs linked with horse genes involved in the regulation of processes of development of connective tissues and the bone system, neural system, immune system regulation, and other processes. The present study is novel and introduces Kazakh horses as a promising genetic source for horse breeding and selection both on the domestic and international levels.

In Modoc County, located in northeastern California, there is a high elevation sage-steppe rangeland ecosystem heavily populated by wild horses and managed primarily by the United States Forest Service (USFS) called the Devil's Garden Plateau. Wild horses have significantly exceeded (roughly 2,000 horses) appropriate management levels (206-402 horses) in recent years and expanded their range outside of the designated territory (258,000 acres) and onto private and tribal lands (nearly 500,000 acres). Increased pressure from wild horses on the multiple use mandate of Forest Service lands have put strains on livestock, wildlife, and the local rural economy. The Modoc National Forest has decreased grazing by roughly 5,000 AUMs (animal unit months) on the Devil’s Garden Plateau due to excessive wild horse use. Each lost AUM results in a decrease of $57.43 - $144.70 of income to Modoc County. Three helicopter gathers in recent years have removed over 1,500 horses from the Devil’s Garden Plateau. Due to the extensive collaboration between the USFS, Modoc National Forest, and local partners, many of these horses have found new homes. This was done by using a tiered pricing approach and offering sales with limitations for older and unadoptable horses. The addition of a robust social media campaign run by volunteers has created a brand for the Devil’s Garden Plateau horses and educated the public on the declining range condition and horse health. Although good progress is being made to gather and place horses in private care, more diverse management solutions may be needed in the future.

Mushroom is a unique coat color phenotype in Shetland Ponies characterized by the dilution of the chestnut coat color to a sepia tone and is hypothesized to be a recessive trait. A genome wide association study (GWAS), utilizing the Affymetrix 670K array (MNEc670k) and a single locus mixed linear model analysis (EMMAX), identified a locus on ECA7 for further investigation (Pcorrected = 2.08 × 10-10). This locus contained a 3 Mb run of homozygosity in the 12 mushroom ponies tested. Analysis of high throughput Illumina sequencing data from one mushroom Shetland pony compared to 87 genomes from horses of various breeds, uncovered a frameshift variant, p.Asp201fs, in the MFSD12 gene encoding the major facilitator superfamily domain containing 12 protein. This variant was perfectly concordant with phenotype in 96 Shetland Ponies (P = 1.15 × 10-22), was identified in the closely related Miniature Horse for which the mushroom phenotype is suspected to occur (fmu = 0.02), and was absent in 252 individuals from seven additional breeds not reported to have the mushroom phenotype. MFSD12 is highly expressed in melanocytes and variants in this gene in humans, mice, and dogs impact pigmentation. Given the role of MFSD12 in melanogenesis, we propose that p.Asp201fs is causal for the dilution observed in mushroom ponies.

Recently, research on domestic mammals' sociocognitive skills toward humans has been prolific, allowing us to better understand the human–animal relationship. For example, horses have been shown to distinguish human beings on the basis of photographs and voices and to have cross-modal mental representations of individual humans and human emotions. This leads to questions such as the extent to which horses can differentiate human attributes such as age. Here, we tested whether horses discriminate human adults from children. In a cross-modal paradigm, we presented 31 female horses with two simultaneous muted videos of a child and an adult saying the same neutral sentence, accompanied by the sound of an adult's or child's voice speaking the sentence. The horses looked significantly longer at the videos that were incongruent with the heard voice than at the congruent videos. We conclude that horses can match adults' and children's faces and voices cross-modally. Moreover, their heart rates increased during children's vocalizations but not during adults'. This suggests that in addition to having mental representations of adults and children, horses have a stronger emotional response to children's voices than adults' voices. [ABSTRACT FROM AUTHOR]

Understanding factors driving resource selection and habitat use of different species is an important component of management and conservation. Feral horses (Equus caballus) are free ranging across various vegetation types in the western United States, yet few studies have quantified their resource selection and seasonal use. We conducted a study to determine effects of vegetation community, distance to water, and topographic variables on seasonal resource selection in 2 feral horse populations in Great Basin sagebrush (Artemisia spp.) ecosystems of west‐central Utah, USA: Conger Herd Management Area (HMA) and Frisco HMA. We deployed global positioning system (GPS) radio‐collars on 38 female horses and GPS‐transmitters braided and glued into the tail hair of 14 males, collecting locations every 2 hours for 1–4 years between 2016 and 2020. We calculated home range size and core use area of social groups (harems) and bachelor males using auto‐correlated kernel density estimators for each biologically defined season (breeding, fall, and winter) per study year. We examined seasonal home range size and overlap of harem groups and bachelor males and compared movement speed of bachelors and harems among seasons. We determined seasonal resource selection in a use‐availability framework using resource selection functions. We hypothesized that horses would select for areas of high herbaceous vegetation, that water would be a key variable in resource selection models like other equids, and home range size in winter would be largest because horses can eat snow for hydration and could therefore roam farther from surface water. Mean annual home range size was 103.12 ± 37.38 km2 (SD) for Conger harems and 117.47 ± 32.75 km2 for Frisco harems. At Conger there was no difference in home range size between harem groups and bachelor males, but home range size was smaller in winter than other seasons, whereas winter home range size at Frisco was larger than other seasons. Bachelor males moved at higher speeds than harems during all seasons, and harem groups from both populations had lower movement speeds in winter. Harem groups had distinct winter ranges with little overlap on breeding season ranges. In both populations, all horses selected for herbaceous vegetation types and avoided forest relative to shrubland throughout the year. Harems at Frisco were consistently located closer to water sources, whereas selection for water sources by Conger harems varied seasonally, with winter having the lowest selection. Harem groups at Conger had an average of 10.6% of their home ranges outside the HMA boundary and Frisco harems had up to 66.8% outside, likely because of the horseshoe shape of Frisco HMA in which shrub meadows (foraging areas) comprise the horseshoe center, which is outside the HMA. Our results highlight the importance of water sources, which were a key predictor of horse movement patterns in our study. We emphasize the utility of telemetry devices to understand resource selection of feral horses at a fine scale, enabling management to be more targeted and facilitate planning. [ABSTRACT FROM AUTHOR]

Simple Summary: How animals perceive animal-assisted interventions (AAI) has been of concern lately, especially as these activities involve many tactile stimulations. It has been shown that tactile reactivity in horses could vary greatly between individuals and could depend upon a variety of factors. Repeated tactile stimulations, according to the associated valence, may lead to lower or higher reactivity. Here we hypothesized that the numerous tactile actions, sometimes with atypical gestures, during AAI may lead to tactile sensitization. In order to test this hypothesis, we tested, with von Frey filaments, the tactile reactivity of 60 horses involved in equine-assisted interventions (EAI), conventional riding school (RS) or mixed activities (EAI-RS). The results indicate that EAI horses showed a higher tactile reactivity than EAI-RS and RS horses, showing a higher number of reactions and a higher reactivity towards thin filaments. These differences could be related to human actions during EAI, as observations of brushing sequences by participants with or without mental and/or developmental disorders revealed differences in the distribution and modalities of tactile actions: participants diagnosed with such disorders brushed more the hindquarters and showed more fragmented actions. These results call for attention towards procedures during EAI and for promoting appropriate tactile actions from participants. Tactile perception in humans varies between individuals and could depend on extrinsic factors such as working activity. In animals, there is no study relating the influence of animals' work and their tactile reactivity per se. We investigated horses' tactile reactivity using von Frey filament in different body areas and compared horses working only in equine-assisted interventions (EAI), in riding school (RS) lessons, and in both activities (EAI-RS). We further compared tactile actions by people with or without mental and/or developmental disorders during brushing sessions. The results indicated that EAI horses showed higher tactile reactivity compared to EAI-RS and RS horses, both in terms of number of reactions overall, and especially when the test involved thin filaments. All horses showed high tactile reactivity when tested on the stifle, and this was particularly true for EAI horses. These differences could be related to humans' actions, as participants diagnosed with disorders brushed more the hindquarters and showed more fragmented actions. This study opens new lines of thought on the influence of EAI working activity on horses' tactile reactivity, and hence, on horses' sensory perception. Tactile reactivity outside work, may be directly (via tactile stimulations) or indirectly (via the welfare state), influenced by working conditions. [ABSTRACT FROM AUTHOR]

Simple Summary: Stress can come in many forms for social animals. We investigated the effects of increased social instability on individual male stress levels in feral horses. When females change groups (thereby leaving one male to join another) stallions will often fight with one another and will remain alert, watching out for rival stallions and monitoring female locations; all potentially stressful behaviors. Such responses can be particularly important in managed populations as contracepted females are more likely to change groups, causing increased social instability in both the groups left and joined. We collected fecal samples from stallions to determine if decreased social instability (caused by females) affected male cortisol metabolite concentrations (an indicator of the physiological stress response). Surprisingly, we found that stallions experiencing increased social instability did not exhibit higher fecal cortisol even while they engaged in the fighting and alert behaviors typically associated with stress. Our results highlight the importance of considering both physiological and behavioral measures when investigating animal responses to challenging situations. Only by using such a holistic approach can we best understand the potential costs animals face; this is especially important in managed populations in which human perturbation can lead to unintended side effects. Stress responses can be triggered by several physical and social factors, prompting physiological reactions including increases in glucocorticoid concentrations. In a population of feral horses (Equus caballus) on Shackleford Banks, North Carolina, females previously immunized with the immunocontraceptive agent porcine zona pellucida (PZP) change social groups (bands) more often than unimmunized females, disrupting the social stability within the population. We assessed the effects of increased female group changing behavior (or female turnover) on individual male stress by comparing fecal cortisol metabolite (FCM) concentrations among stallions experiencing varying amounts of female group changing behavior. FCM concentrations did not significantly correlate with female turnover. Similarly, FCM concentrations were not dependent upon the timing of female group changing behavior. These findings suggest that female turnover rate has little influence on physiological measures of stress in associated stallions. That said, Shackleford stallions experiencing increased female turnover do engage in behaviors typically associated with stress (increased vigilance, highly escalated male-male conflicts). Future work should compare FCM concentrations across time within populations and among populations managed under different strategies to better isolate factors influencing stallion stress physiology. Such studies are especially important if we are to determine how changes in female behavior related to immunocontraception impact physiological and behavioral indicators of stress for non-target animals. Finally, our study highlights the importance of considering both physiological and behavioral measures when investigating animal responses to potentially challenging situations. [ABSTRACT FROM AUTHOR]

Objective: The semen quality of stallions including sperm motility is an important target of selection as it has a high level of individual variability. However, effects of the molecular architecture of the genome on the mechanisms of sperm formation and their preservation after thawing have been poorly investigated. Here, we conducted a genome-wide association study (GWAS) for the sperm motility of cryopreserved semen in stallions of various breeds. Methods: Semen samples were collected from the stallions of 23 horse breeds. The following semen characteristics were examined: progressive motility (PM), progressive motility after freezing (FPM), and the difference between PM and FPM. The respective DNA samples from these stallions were genotyped using Axiom Equine Genotyping Array. Results: We performed a GWAS search for single nucleotide polymorphism (SNP) markers and potential genes related to motility properties of frozen-thawed semen in the stallions of various breeds. As a result of the GWAS analysis, two SNP markers, rs1141327473 and rs1149048772, were identified that were associated with preservation of the frozen-thawed stallion sperm motility, the relevant putative candidate genes being NME/NM23 family member 8 (NME8), olfactory receptor family 2 subfamily AP member 1 (OR2AP1), and olfactory receptor family 6 subfamily C member 4 (OR6C4). Potential implications of effects of these genes on sperm motility are herein discussed. Conclusion: The GWAS results enabled us to localize novel SNPs and candidate genes for sperm motility in stallions. Implications of the study for horse breeding and genetics are a better understanding of genomic regions and candidate genes underlying stallion sperm quality, and improvement in horse reproduction and breeding techniques. The identified markers and genes for sperm cryotolerance and the respective genomic regions are promising candidates for further studying the biological processes in the formation and function of the stallion reproductive system. [ABSTRACT FROM AUTHOR]

During initial maternal recognition of pregnancy (MRP), the equine embryo displays a series of unique events characterized by rapid blastocyst expansion, secretion of a diverse array of molecules, and transuterine migration to interact with the uterine surface. Up to date, the intricate transcriptome and proteome changes of the embryo underlying these events have not been critically studied in horses. Thus, the objective of this study was to perform an integrative transcriptomic (including mRNA, miRNAs, and other small non‐coding RNAs) and proteomic analysis of embryos collected from days 10 to 13 of gestation. The results revealed dynamic transcriptome profiles with a total of 1311 differentially expressed genes, including 18 microRNAs (miRNAs). Two main profiles for mRNAs and miRNAs were identified, one with higher expression in embryos ≤5 mm and the second with higher expression in embryos ≥7 mm. At the protein level, similar results were obtained, with 259 differentially abundant proteins between small and large embryos. Overall, the findings demonstrated fine‐tuned transcriptomic and proteomic regulations in the developing embryo associated with embryo growth. The identification of specific regulation of mRNAs, proteins, and miRNAs on days 12 and 13 of gestation suggested these molecules as pivotal for embryo development and as involved in MRP, and in establishment of pregnancy in general. In addition, the results revealed new insights into prostaglandin synthesis by the equine embryo, miRNAs and genes potentially involved in modulation of the maternal immune response, regulation of endometrial receptivity and of late implantation in the mare. [ABSTRACT FROM AUTHOR]

There is limited research into horse slaughter, particularly ante mortem welfare, and the effectiveness of captive-bolt gun (CBG) stunning, despite this being a widely used method worldwide. To address this evidence gap and explore associations between ante and post mortem factors, the welfare of 62 horses was assessed at a commercial Italian abattoir. Animal-based measures were used to identify stress-related behaviours and stunning effectiveness. A sub-sample (44%; 27/62) of heads were assessed for gross brain pathology. All animals in the study showed stress-related behaviours at all stages of the slaughter process. Additionally, 53% (33/62) of horses slipped in the stunning box, with poor floor surface condition and use of force associated with this. At least one sign of an ineffective stun was observed in 22% (14/62) of animals. Six animals were shot twice, with the application of a second shot significantly associated with a higher stress behaviour index score in the stunning box. Damage to critical brainstem structures was found in 85% (23/27) of heads that were assessed with gross pathology. An absence of damage to critical brainstem structures meant that animals were ten times more likely to show signs of ineffective stunning. These results highlight the risks to equine welfare throughout the slaughter process and suggest that mitigating ante mortem stress could improve stunning effectiveness, whilst CBG usage should be refined to ensure that critical brainstem structures are targeted., Competing Interests: None., (© The Author(s) 2025.)