Mares and horses are integral components of equine studies, focusing on the reproductive and behavioral aspects of equine biology. Mares, or adult female horses, play a significant role in breeding programs and are often studied for their reproductive physiology, gestation, and maternal behaviors. Horses, as a broader category, encompass both sexes and all age groups, providing a comprehensive view of equine anatomy, physiology, and behavior. Research in this area often investigates the differences and similarities between mares and other horses in terms of hormonal cycles, reproductive health, and social interactions. This page compiles peer-reviewed studies and scholarly articles that explore the biological and behavioral characteristics of mares and horses, offering insights into their roles in equine science and management.
HOLMES AD, JONES CP.Fifteen samples of mares' milk with initial potencies of from 86 mg to 161 mg of reduced ascorbic acid per liter were stored in the dark at 10°C. They were assayed at daily or longer intervals. Four samples observed for 10 days lost an average of 2.5 mg per liter daily; 4 samples stored 20 days lost 1.8 mg per day; 2 stored 28 days lost 1.3 mg daily; and 3 observed for 33 days lost 1.1 mg per liter per day. These data show that the rate of loss of reduced ascorbic acid from mares' milk is only a fraction of the rate of loss from cows' milk.
HENNING MW.1. Two outbreaks of infectious equine abortions are reported; both
with a very high abortion incidence.
2. In the majority of the abortions studied the foetal organs were found
to be extensively invaded by S. abortus-equi but in others this organism
could not be recovered from the foetus or after-birth.
3. Both donkey and horse mares were found to be susceptible, donkeys
being on the whole more resistant than horses.
4. Abortion was successfully produced in both horse and donkey mares
by means of (a) the oral administration of minced abortus-equi infected
foetal organs (4 cas...
Uterine torsion typically occurs during mid to late gestation and is estimated to cause 5% to 10% of all equine obstetric emergencies. Clinical signs include abdominal pain that may be mistaken for gastrointestinal distress, parturition, or abortion. Uterine torsion is an emergency for the mare and fetus, and early recognition and intervention are essential to optimizing the chance of survival. This article reviews the etiology, diagnosis, treatment, and prognosis of uterine torsion in mares.
Mares were inseminated with motile spermatozoa suspended in 30-150 microliters Tyrode's medium directly onto the uterotubal papilla at the anterior tip of the uterine horn, ipsilateral to the ovary containing a dominant preovulatory follicle of > or = 35 mm in diameter, by means of a fine gamete intrafallopian transfer (GIFT) catheter passed through the working channel of a strobed light videoendoscope. Insemination of 10, 8, 25, 14, 11 and 10 mares with, respectively, 10.0, 5.0, 1.0, 0.5, 0.1 or 0.001 x 10(6) motile spermatozoa resulted in conception rates of, respectively, 60, 75, 64, 29,...
Eight mares with third-degree rectovestibular lacerations were treated by a two-stage surgical technique. The rectovestibular shelf was corrected with three parallel 'circular' continuous suture rows distributed along the longitudinal axis of the vagina, and the perineal body was reconstructed with three divergent simple continuous rows. Primary healing of the first-stage surgery occurred in all the mares. Seven of the mares completed the two-stage surgery and primary healing occurred in all of them. One of them returned to endurance racing competition and one was lost to follow-up. The other ...
Derar D, Ali A, Al-Sobayil F, Refaai W.Granulosa cell tumors (GCTs) represent the most common ovarian neoplasms in mares, yet data on their epidemiology, risk factors, and clinical outcomes in Arabian horses are limited. Understanding their prevalence and diagnostic features is crucial for improving fertility management in this breed. Unassigned: Clinical records from 807 Arabian mares housed on 35 stud farms in central Saudi Arabia were retrospectively reviewed to determine the prevalence of GCT and potential risk factors, including age, parity, and anabolic steroid use. Twenty-four confirmed cases were further investigated using ...
Fresa K, Catandi GD, Gonzalez-Castro R, Omar A, Whitcomb LA, Cheng MH, Chen TW, Carnevale EM, Chicco AJ.Advancing age is associated with a decline in fertility and functional capacity, which may result in part from suboptimal nutrition and impaired mitochondrial function. Dietary essential polyunsaturated fatty acids (PUFA) are broadly recommended to mitigate weight loss and reduce risk of chronic disease in aged populations, but their effects on mitochondrial function are less clear. The present study investigated the impacts of dietary supplementation with essential omega-3 PUFA (flaxseed oil; N3) or omega-6 PUFA (corn oil, N6) on blood, muscle and follicular cell fatty acid composition and mi...
Aiche S, Chikhaoui M, Smail F, Benamor N, Benia AR.Pregnancy causes increased oxidative stress in mares, possibly harming both the mare and the foal, whereas the effects of different exercise levels on oxidative stress and lipid metabolism during pregnancy remain unclear. Objective: For this reason, the aim of this research was to explore the impacts of different training intensities on oxidative stress and lipid metabolism during pregnancy. Methods: The study comprised 22 clinically normal Purebred Arabian mares from Algeria, which were divided into three groups according to age and exercise frequency. Blood samples were collected during both...
Satué K, Fauci D, Fazio E, Velasco-Martínez MG, Bruschetta G, Medica P.This study investigates sequential changes in serum protein fractions during gestation in 31 pregnant Spanish Purebred mares compared to 15 non-pregnant control. Total serum proteins (TSP) were measured using the Biuret method, while albumin (ALB), total globulins (tGLOB), and their subfractions (α₁, α₂, β₁, β₂, γ-GLOB) were analyzed by agarose gel electrophoresis. Pregnant mares showed significant changes in serum protein profiles throughout gestation. TSP and tGLOB concentrations increased from mid to late pregnancy (months 6-11), while ALB concentrations declined between months...
Mendoza Cerna MN, Anderson H, Avni G, Kahila Bar-Gal G, Juras R, Raudsepp T.Robertsonian translocations (ROBs) or centric fusions of acrocentric chromosomes are the most common structural chromosomal rearrangements in mammals. ROBs are of medical and veterinary concern because of associated subfertility and congenital disorders but are also of interest as a mechanism of chromosome and karyotype evolution. While ROBs are well documented in humans, mice, and cattle/bovids, they are extremely rare in horses, despite the 18 acrocentric chromosomes in the horse karyotype. Methods: We characterize the case using conventional and molecular cytogenetic approaches and DNA anal...
Bolesławska-Szubartowska J, Kucharczuk M, Skrabska A, Zbysław A, Adamowicz J, Alszko A, Domagalska-Stomska K, Durska M, Dziekcierów A....Pain after giving birth is commonly observed in horses, yet there has not been a specific tool developed for assessing this pain in postpartum mares. The goal was to adapt existing equine pain scales and to preliminarily validate a practical pain scale for use by veterinarians and caregivers after foaling. Methods: The pain scale was developed by adapting items from other pain scales, including established orthopedic and colic equine pain scales, and incorporating caregiver feedback. The final scale includes eight areas for assessing pain: behavior, facial expressions, vital signs, udder exami...
Dantas FTDR, Canisso IF, Feijó LS, de Vasconcelos PMF, Campos ML, Ulanov AV, Li Z, Pizzi GLBL, Nogueira CEW, Curcio BR.Doxycycline is widely used in equine medicine, yet data on its pharmacokinetics and safety during late gestation are scarce. We investigated the pharmacokinetics, fetoplacental diffusion, and safety of compounded oral doxycycline in late-term pregnant mares. In the first experiment, six mares at 300 days of gestation received a single oral dose (10 mg/kg), and plasma concentrations were measured using LC-MS/MS. Pharmacokinetic analysis using non-compartmental and compartmental models showed rapid absorption, with a mean Cmax of about 6000 ng/mL reached within 0.8 h and a terminal half-life ...
Rönnow E, Roth LSV.Compared to other companion animals, our understanding of the human-horse relationship is limited, particularly from the horse's perspective. This pilot study examined whether horses (N = 30) show a bias towards their owner in a reunion in the presence of both the owner and a stranger. Afterwards, the horses were also presented with the odor of the owner and a stranger. Both tests were video recorded for behavioral analyzation. No significant owner-directed bias was observed at the group level in either the reunion test or the odor test. Nonetheless, in the reunion test, owner bias in physical...
Risvanli A, Salykov R, Timurkaan N, Seker I, Ekinci E.This study was conducted to examine glandular histological changes in the uterus of Kyrgyz breed mares during the first 6 months of pregnancy. The study used 53 Kyrgyz breed mares; 43 of these were at different stages of pregnancy, while 10 were non-pregnant mares. Uterine samples obtained at the slaughterhouse were evaluated histomorphometrically; endometrial thickness, gland density, gland epithelial height and gland diameter were measured. In conclusion, it was concluded that in Kyrgyz mares, endometrial thickness, glandular epithelial height and diameter increased as pregnancy progressed...
Ramsaran LN, Byron M, Parry S, Lection J, Back B, Grenier J, Cheong SH, Diel de Amorim M.Real-time reverse transcription quantitative polymerase chain reaction (RT-qPCR) is a technique that allows for the semi-quantification of mRNA transcripts present within a tissue of interest. Differences in the relative abundance of mRNA between samples detected by RT-qPCR require normalization with a reference gene or genes whose transcript abundance is stable within the tissue of interest independent of experimental conditions. In the field of equine reproductive studies, ACTB, GAPDH and B2M genes are the most widely used as reference genes for the normalization of RT-qPCR results. However,...
Rodrigues MF, Neves AP, Ferreira R, Pessoa GA, Araujo DN, de Souza GV.Melatonin has demonstrated beneficial effects in regulating inflammatory processes in various tissues, but its role in mare uterine physiology remains unclear. Objective: To investigate the effects of melatonin on the gene expression of cytokines (IL-1β, IL-6, IL-8, IL-10, and TNF-α) in equine uterine explants cultured for 6, 12, or 24 hours. Methods: The study was divided into two experiments. Part 1 aimed to evaluate the cytotoxicity of melatonin at concentrations of 0, 0.5, 1, 2, 4, and 8 mM on endometrial cells. Part 2 aimed to determine the expression of inflammatory cytokines in uterin...
Moroni R, Fanelli D, Maltinti S, Orefice M, Rota A, Camillo F, Melanie P, Cantile C, Miragliotta V, Pirone A, Lazzarini G, Passamonti F, Marmorini P....Equine persistent breeding-induced endometritis can lead to chronic uterine inflammation and fibrosis, reducing fertility. Intrauterine ozone (O₃) has recently been proposed as a potential treatment for mares unresponsive to conventional therapies. This case series describes O₃ treatment in eleven mares barren for at least one year despite multiple inseminations attempts. During the first oestrous cycle, low-volume uterine lavage and endometrial biopsy were performed, followed by 3 consecutive days of intrauterine O₂-O₃ gas insufflation. In the subsequent cycle, both procedures were re...
Lewczuk D, Borowska A, Maśko M, Bagnicka E.: Knowledge of the genetic background of evaluated traits has been the basis for genetic progress in every horse-breeding population and is essential for precise breeding and up-to-date decision-making. The study aimed to estimate the heritability coefficients for field performance traits in mares. : The research was based on 1408 evaluations of mares conducted during the years 2002-2021 in 51 training centers in Poland. The preliminary analyses of the effects, significant for the investigated traits, were obtained using analysis of variance, and these additional data are also presented (SAS p...
The research aims to study the dynamics of reproductive system pathologies in mares of Kazakh and Mugalzhar horse breeds and their impact on the reproductive traits of the breeding stock. The object of the research was horses of the Kazakh and Mugalzhar breeds. The formation of experimental groups was carried out using the pair-analog method. It was found that the frequency of detection of infertile mares is 13.8-25.0%. Subinvolution of the uterus from the total number of infertile mares is 8.3-10.7%, endometritis - 16.6-23.3%, atony and hypotonia of the uterus - 8.3-13.3%, ovarian diseases - ...
Loncar KD, Ortis HA, Foss RR.Production of embryos via intracytoplasmic sperm injection (ICSI) is a common clinical procedure in equine practice. A recent study indicates that treatment of mares with phenylbutazone paste significantly lowers blastocyst production after ICSI of recovered oocytes. The current study was conducted to determine the effect of different methods of phenylbutazone administration on in vitro embryo production of recovered oocytes in mares. Unassigned: In study 1 (July 29 through September 18, 2024), 14 mares received either oral liquid phenylbutazone once daily for 10 days or no treatment. On the l...
Pyles MB, Fowler AL, Crum AD, Hayes SH, Schendel RR, Lawrence LM.Mare milk is the primary source of nutrients for neonatal foals and contains various carbohydrates. Milk oligosaccharides are complex carbohydrates that are resistant to enzymatic digestion and provide support for the immune system and developing microbiome in the neonate. However, factors influencing the synthesis of milk carbohydrates in the mare are not well understood. This study aimed to determine the effects of dietary nonstructural carbohydrate (NSC) on mare milk composition and yield. Thoroughbred mares were paired by age and last breeding date then randomly assigned to one of two diet...
Africa DD, Ikeda K, Maeda T, Inoue S, Ringhofer M, Yamamoto S, Go CK.Collective decision-making and movement coordination are essential behaviours observed in biological systems, from animal herds to human crowds. Horses are a highly social species with a multilevel society. Herding, where the harem is collected to move in a certain direction, is an often-cited example of agonistic behaviour in horses, yet poorly understood in a granular, quantitative sense. We use transfer entropy to measure herding in a harem group of feral Garrano ponies in Serra D'Arga, Portugal. First, we characterize the harem's leader-follower relationships by quantifying the time lag (a...
Wang C, Wang J, Ma B, Liu T, Yuan X, Meng J, Zeng Y.: This study investigated the effects of dietary bamboo leaf extract (BLE) on milk parameters and intestinal microbiota in lactating mares. : Twenty-four mares of similar age (10 ± 2 years), weight (360.62 ± 15.23 kg) and body condition were selected for this study and randomly divided into four groups of six mares each: an untreated control group (CG) and three experimental groups (EG1, EG2, EG3) were fed a basal diet supplemented with 0, 10, 20, or 30 g/day of BLE, respectively, for 60 days. Then, horse milk composition, antioxidant activity, and immunoglobulin levels along with the rela...
Pinto-Bravo P, Rebordão MR, Amaral AS, Szóstek-Mioduchowska A, Fernandes C, Galvão AM, Silva E, Alpoim-Moreira J, da Costa RPR, Skarzynski DJ....Oviduct glycoprotein 1 (OVGP1) is a key protein involved in oviductal functions. β-estradiol (E) and progesterone (P), oxytocin (OXT) and tumor necrosis factor-α (TNFα) modulate the equine oviduct function, through prostaglandin regulation. The objective was to evaluate OVGP1 expression within each equine oviduct segment (infundibulum, ampulla isthmus), throughout the estrous cycle. The in vitro effect of (i) E, P, OXT, TNFα; and (ii) spermatozoa, on oviduct OVGP1 transcription and secretion was studied. Gene transcription was assessed by real-time PCR; protein expression by western blot; ...
Boakari Y, El-Sheikh Ali H, Almeida GHDR, Scoggin KE, Fernandes CB, Marchio SP, Troedsson MHT, Carreira ACO.Equine placental dysfunction impairs fetal growth and disrupts pregnancy outcomes. Despite many advances in diagnosis, the molecular pathophysiology of equine placentitis and premature placental separation remains poorly understood. However, the hypoxia-inducible factor (HIF-α) pathway is related to placental hypoxia, and its modulation in placental diseases has been shown in other species. Therefore, we hypothesized that in conditions marked by equine placental dysfunction, oxygen deprivation in the chorioallantois membrane triggers the activation of the HIF-α pathway, which is related to m...
Wasiński B, Złotnicka J, Kubajka M, Olejarczyk M, Szulowski K.Contagious equine metritis (CEM) is a cosmopolitan infectious, venereal disease of equids caused by the bacterium . Its frequently asymptomatic course leads to its prevalence sometimes being underestimated, and knowledge of the spread of infections with its causative agent is insufficient. The aim of this study is to summarise and present data on the incidence of infections in horses in Poland. Unassigned: In the years 2018-2023, routine laboratory tests of horses for CEM were carried out. Between 52 and 99 horses were examined annually. Swabs from the external parts of the urogenital system ...
Newcombe JR, Claes AN, Cuervo-Arango J.Early embryonic loss (EEL), particularly between Days 14 and 42 of pregnancy, remains a key concern in equine reproduction. This study investigates the incidence of spontaneous luteolysis-used here as a marker of maternal recognition of pregnancy (MRP) failure-in both pregnant Thoroughbred (TB) broodmares and recipient mares carrying either in vivo-derived (IVD) or in vitro-produced (IVP) embryos. Retrospective reproductive data from 2078 pregnancies in TB and 532 pregnancies in recipients were analysed to determine the incidence and characteristics of clinical luteolysis during pregnancy. Ove...
Stasiak K, Dunowska M, Rola J.Equid herpesvirus 5 (EHV-5) comprises a group of heterogeneous viruses with a worldwide distribution. Primary infection typically occurs early in life, which is followed by latency and periodic recrudescence of the virus. The aim of this study was to determine the genetic variation of EHV-5 in individual animals over time and to determine the dynamics of EHV-5 spread among selected mare-foal pairs at three horse studs. The partial glycoprotein B () gene was amplified from archival nasal swab samples. Sequences from 3-5 clones from each PCR product were compared using identity matrix, phylogeny...
Couto GR, Vigano DWA, Santos GDC, Allen WRT, Wilsher S.Vitrified embryos ≤300 μm give better pregnancy rates following warming and transfer than larger ones. Embryo recovery undertaken close to when the embryo enters the uterus (Day 6-6.5) helps in the recovery of embryos ≤300 μm. However, flushing early can mean missing an embryo not yet in the uterus, whereas later can result in embryos >300 μm. Objective: To evaluate if repeated embryo flushing on consecutive days from Day 6.5 would increase the number of embryos ≤300μm recovered. Methods: Retrospective case series. Methods: Four hundred and ninety-six inseminations with cooled ...
Muñoz-García CC, Soriano-Campos MP, Luis-Calero M, Gallardo-Soler A, González-Fernández L, Macías-García B.The use of mesenchymal stromal cells (MSCs) in equine reproduction is increasing its interest in the treatment of specific pathologies. MSCs have been isolated from follicular aspirates obtained during transvaginal oocyte aspiration in women, offering a novel source for autologous therapies in reproductive treatments. However, this approach has not been tested in mares despite the common use of transvaginal oocyte aspiration for oocyte collection to produce equine embryos in vitro. Our study aimed to investigate the feasibility of isolating MSCs from equine ovarian follicular aspirates obtaine...
Octaviano JI, Alonso MA, Boakari YL, Gomes V, Mori CS, Fleury PDC, Fernandes CB.Monitoring equine parturition effectively is essential for preemptive intervention in periparturient issues and ensuring the overall well-being of both mares and foals. However, its implementation in breeding farms is challenging due to variable gestational lengths and nocturnal births. Predictive techniques have the potential to streamline the monitoring process, reduce labor intensity, and minimize costs. Research on foaling prediction in mares carrying mule or equine clone fetuses is scarce. Therefore, this study aimed to comparatively analyze foaling prediction parameters in mares pregnant...
Gomes VCL, Strachota JR.This article explores key complications in equine reproduction, focusing on their causes, diagnosis, treatment, and prevention. It emphasizes the risks associated with common procedures, particularly those that are iatrogenic, meaning caused by medical intervention. The discussion highlights how understanding these risks can help in early detection and management, ultimately improving reproductive success and animal welfare. The article also provides insights into best practices to minimize complications, ensuring safer procedures and better outcomes for breeding horses.
Domańska D, Witkowska-Piłaszewicz O, Trela M, Pawłowski K, Pawliński B, Domino M.Mastitis is an emerging health concern in lactating mares, particularly given the growing commercial interest in mare's milk. This study evaluated the diagnostic potential of acute phase proteins (APPs), specifically serum amyloid A (SAA), milk amyloid A (MAA), and haptoglobin (Hp), measured in blood and milk as indicators of clinical and subclinical mastitis. Twenty-four Thoroughbred mares were prospectively monitored during lactation and weaning. Plasma and milk samples were collected and analyzed using commercial ELISA kits. Plasma SAA concentrations were significantly higher in mares with ...
Werle J, Nunes GT, Machado CS, Silva CBD, Vogel FSF, Vargas APC, Cargnelutti JF.The genus Corynebacterium encompasses versatile bacteria that act as natural microbiota or pathogens, causing infections in humans and animals, including equine reproductive disorders. Corynebacterium uterequi (C. uterequi) is a potential pathogen in mares, associated with reproductive disorders including endometritis, embryonic loss, and infertility, raising concerns for equine reproductive health. This study aimed to characterize C. uterequi isolates from mares in southern Brazil and deepen the understanding of this species. Phenotypic, molecular, and phylogenetic analyses were performed on ...
Muñoz-Jurado A, Requena F, Agüera EI, Escribano BM.Anti-Müllerian hormone (AMH) is a dimeric glycoprotein belonging to the superfamily of the transforming growth factor-β. Due to the discovery of AMH functions, relative to the ovarian function, it is being postulated as being a highly important marker in studies on mammalian reproduction. Therefore, the objective of this review was to describe the role of this hormone in different reproductive aspects of female mammals, taking women, cows, and mares as reference species. The relationship between ovarian reserve and AMH was analysed, and it has been verified that there is a relationship betwe...
