Pregnancy in horses, or equine gestation, is a physiological process that involves the development of a foal within the mare over approximately 11 months. This period is characterized by distinct stages, including fertilization, embryonic development, and fetal growth. Throughout gestation, mares undergo various physiological and hormonal changes to support the developing fetus. Monitoring pregnancy in horses involves assessing fetal health and mare well-being through veterinary examinations and diagnostic tools such as ultrasound. This page compiles peer-reviewed research studies and scholarly articles that explore the physiological processes, management practices, and health considerations associated with equine pregnancy.
Koroleva E, Steffen HC, Bosch C, Flemming L, Botha A.Increasing cases of equine infertility and early embryonic loss in the Western Cape, South Africa, were documented in recent years. These appeared to be associated with Corynebacterium uterequi isolated from the uteri of infected mares. The purpose of this study was, therefore, to investigate the physiology and potential pathogenicity of this bacterium. Histopathological analyses were conducted on five mares suffering from reproductive complications, and from which Corynebacterium strains were detected on culture of uterine swabs. The histopathology revealed that the mares suffered from variou...
Rørvang MV, Nicova K, Yngvesson J.In spite of a highly developed olfactory apparatus of horses, implying a high adaptive value, research on equine olfaction is sparse. Our limited knowledge on equine olfaction poses a risk that horse behavior does not match human expectations, as horses might react fearful when exposed to certain odors, which humans do not consider as frightening. The benefit of acquiring more knowledge of equine olfaction is therefore twofold; (1) it can aid the understanding of horse behavior and hence reduce the risk of dangerous situations, and (2) there may be unexplored potential of using odors in severa...
Inoue S.Maternal aging has negative influences on the development and racing performance of their offspring in racehorses. However, the mechanism by which pregnancy at old age reduces the race performance of the offspring is unknown. Here, two hypotheses were posited: 1) Foals born to older mares are more likely to have muscular, skeletal, and cognitive disadvantages (direct effects). 2) Foals born to older mares are more likely to be affected by non-physiological factors correlating with the mare's age, such as the quality of sires (e.g. low-quality sires are likely to be chosen as partners of older ...
Salem SE, Sinnott A, Roach JM, Verheyen KLP, de Mestre AM.Multiple pregnancies (MPs) are commonly diagnosed during breeding management of mares. Whilst some studies have reported on factors associated with the risk of MPs, few have utilised multivariable data analysis to control for confounding variables. A prospective cohort study of Thoroughbred broodmares was conducted with information collected on 27 factors. Mixed-effects logistic regression was used to determine risk factors for MPs. Mare, stallion, stud, and veterinarian were evaluated as random effects. The prevalence of MPs in 1754 mares and 2245 pregnancies was 16.06% (95% confidence interv...
Müller A, Glüge S, Vidondo B, Wróbel A, Ott T, Sieme H, Burger D.Prediction of impending foaling is highly desirable as early intervention may improve mare and foal outcomes. However, monitoring the peripartum mare is a time-consuming challenge for breeders and many foaling prediction systems have limitations. "Heating up" of the mare is empirically used by breeders as a sign of upcoming parturition in mares. The purpose of this study was to investigate if an increase in skin temperature shortly before parturition is detectable and to determine whether such physiological changes could be an additional valuable parameter to predict foaling. For that, 56 foal...
Handschuh S, Okada CTC, Walter I, Aurich C, Glösmann M.Here, we describe a workflow for high-detail microCT imaging of formalin-fixed and paraffin-embedded (FFPE) equine embryos recovered on Day 34 of pregnancy (E34), a period just before placenta formation. The presented imaging methods are suitable for large animals' embryos with intention to study morphological and developmental aspects, but more generally can be adopted for all kinds of FFPE tissue specimens. Microscopic 3D imaging techniques such as microCT are important tools for detecting and studying normal embryogenesis and developmental disorders. To date, microCT imaging of vertebrate e...
Colombo I, Podico G, Rudolf-Vegas A, Bauersachs S, Canisso IF.Progesterone is pivotal to maintain pregnancy in the first trimester and low concentration ( .05). Multiple ovulations were associated with greater progesterone concentration and luteal tissue area (P = .0001). There was a moderate positive association between the number of ovulations and luteal tissue area (r = 0.54; P = .0001). The lack of change in the progesterone concentration and luteal tissue area between bred and non-bred mares suggests that horse seminal plasma does not affect luteal function in mares. As all mares had progesterone above 4 ng/mL after 5-days post-ovulation; it i...
Fanelli D, Beltramo M, Conte G, Cerretini B, Lomet D, Rota A, Aucagne V, Camillo F, Panzani D.Kisspeptins (KPs) are the most potent stimulating neurotransmitters of GnRH release, and consequently KP administration triggers LH and/or FSH release. In small ruminants, KP or its analogs induced an LH surge followed by ovulation in both cyclic and acyclic animals, while in the mare KP only increased LH plasma levels but failed to induce ovulation. This study in jennies compares the endocrinological effects, ovulatory and pregnancy rates of the KP analog C6 and the GnRH analog buserelin acetate. The ovarian activity of nine Amiata jennies was monitored daily by transrectal ultrasound for thr...
Derisoud E, Jouneau L, Dubois C, Archilla C, Jaszczyszyn Y, Legendre R, Daniel N, Peynot N, Dahirel M, Auclair-Ronzaud J, Wimel L, Duranthon V....Breeding a mare until she is not fertile or even until her death is common in equine industry but the fertility decreases as the mare age increases. Embryo loss due to reduced embryo quality is partly accountable for this observation. Here, the effect of mare's age on blastocysts' gene expression was explored. Day 8 post-ovulation embryos were collected from multiparous young (YM, 6-year-old, N = 5) and older (OM, > 10-year-old, N = 6) non-nursing Saddlebred mares, inseminated with the semen of one stallion. Pure or inner cell mass (ICM) enriched trophoblast, obtained by embryo bise...
Murase H, El-Sheikh Ali H, Ruby RE, Scoggin KE, Ball BA.Equine premature placental separation (PPS) is poorly understood and represents an important risk factor for fetal/neonatal hypoxia. Objective: To examine transcriptomic changes in the chorioallantois (CA) from mares with clinical PPS compared with the CA from normal foaling mares. Differential gene expression was determined and gene ontology as well as molecular pathways related to PPS were characterised. Methods: Retrospective case: control study. Methods: CA were collected from Thoroughbred mares with a clinical history of PPS (n = 33) and from control Thoroughbred mares (n = 4) with no...
Fedorka CE, El-Sheikh Ali H, Scoggin KE, Loux SC, Ball BA, Troedsson MHT.Ascending placentitis is the leading cause of abortion in the horse. The pleiotropic cytokine tumor necrosis factor (TNF) is an upstream regulator of this disease, but little is understood regarding its function in pregnancy maintenance or placental infection. To assess this, RNA sequencing was performed on chorioallantois and endometrium of healthy pregnant mares at various gestational lengths (n = 4/gestational age), in addition to postpartum chorioallantois, and diestrus endometrium to assess expression of TNF, TNFR-1, and TNFR-2. Additionally, ascending placentitis was induced via trans-...
Ledeck J, Dufour P, Evrard É, Le Goff C, Peeters S, Brutinel F, Egyptien S, Deleuze S, Cavalier É, Ponthier J.This study describes 17-β-estradiol (E2), estrone (E1) and estrone-sulfate (E1S) concentrations between 4 and 11 months in healthy equine pregnancies of two different breeds using Liquid Chromatography coupled to Mass-Spectrometry (LC-MS). In 2 stud-farms including 15 Spanish PureBred (SPB) and 11 Showjumping (SJ) types mares, combined thickness of the uterus and the placenta (CTUP) was measured and blood was sampled monthly between 4 and 11 months of gestation. Concentrations of E2, E1 and E1S were assayed with LC-MS in mares with normal CTUP. Effects of breed, day of pregnancy and mare's pa...
Magalhaes HB, Canisso IF.Practitioners are frequently requested to diagnose and stage pregnancy in donkeys with unknown breeding dates; however, scant work has been done to stage pregnancy in the species. Therefore, this study aimed to determine the association between measurements of fetal aortic, thoracic, and heartbeat with gestational age in donkeys carrying and delivering healthy foals. Multiparous Dezhou donkeys (n = 50) ranging from 4 to 16 years were enrolled in the study by 150 days of gestation. Transabdominal ultrasonography coupled with a 3.5 MHz sectorial convex transducer was performed at 30 day-interv...
Pollard CL, Gibb Z, Clulow J, Ruiz A, Sheridan A, Bahrami M, Swegen A, Grupen CG.A deficiency in NAD has previously been linked with increased occurrences of congenital abnormalities and embryonic death in humans and mice. Early embryonic death is a major factor involved in pregnancy loss in mares, and very little is known regarding the NAD requirements for optimum reproductive function in horses. The aim of this study was to determine the effect of supplementing the diet of mares with nicotinic acid (NA) on the composition of NAD metabolites in the blood and follicular fluid. Vehicle alone or NA (3 g per os) were administered to seven mares over a minimum of 3 consecutive...
Satué K, Fazio E, Muñoz A, Medica P.The objective of this research was to evaluate the changes in body condition score (BCS), age and the main biochemical parameters in pregnant Spanish Purebred mares. A total of 45 pregnant Spanish broodmares has been studied, classified in three different groups: group A (n = 15), aging 14-18 years old and BCS lower than 4 of 10, group B (n = 15), with ages of 4 to 8 years and a BCS of 5-6/10, and group C (n = 15), aging between 6 and 11 years and a BCS of 8 of 10. Three pregnancy periods were considered: the 1st period, from the 1st to the 3rd, the 2nd from the 4th to the 6th, and the l...
Nocera I, Bonelli F, Turini L, Madrigali A, Aliboni B, Sgorbini M.The body condition score (BCS) represents a practical but subjective method for assessing body fat reserves. Real time ultrasonography (RTU) has been proposed as an accurate method to objectively measure subcutaneous fat (SF) thickness and predict body fat reserves in cows, horses and donkeys. The aim of the present study was to describe RTU measures of SF thickness during periparturient period in jennies. The present prospective cohort study evaluated six dairy jennies. SF RTU were performed at 15 and 7 days before the presumptive delivery, and 2, 15 and 30 days after delivery. A portable ult...
Yu K, Pfeiffer C, Burden C, Krekeler N, Marth C.Increased ambient temperatures has been identified to contribute to reproductive outcomes for several domesticated species, but its impact on equine reproduction has not been previously investigated. Therefore, this study aimed to examine the relationship between ambient climatic conditions, as measured by temperature-humidity index (THI) between day 7 and day 14 of gestation, and early embryonic loss (EEL) in recipient mares undergoing embryo transfer. The study examined records from 834 embryo transfers at an equine breeding facility in Victoria, Australia. Early embryonic loss was defined a...
This study investigated the effects of embryo reduction and transfer of Day 11 embryos, with or without subsequent reduction, on luteostasis in the mare. In Experiment 1, reduction of embryos at Days 10 (n = 15), 11 (n = 47), 12 (n = 36), 13 (n = 27), 14 (n = 5) and 16 (n = 2) of pregnancy resulted in luteostasis in 13%, 47%, 78%, 89%, 80% and 100% mares. Mares undergoing > 1 embryo reduction showed consistency in when luteostasis occurred. In Experiment 2, transfer of Day 11 embryos to recipient mares 10 (n = 9), 11 (n = 8), 12 (n = 9) and 13 (n = 8) days post ovulatio...
Lanci A, Mariella J, Ellero N, Faoro A, Peric T, Prandi A, Freccero F, Castagnetti C.Equine fetal hair starts to grow at around 270 days of pregnancy, and hair collected at birth reflects hormones of the last third of pregnancy. The study aimed to evaluate cortisol (CORT) and dehydroepiandrosterone-sulfate (DHEA-S) concentrations and their ratio in the trichological matrix of foals and mares in relation to their clinical parameters; the clinical condition of the neonate (study 1); the housing place at parturition (study 2). In study 1, 107 mare-foal pairs were divided into healthy (group H; n = 56) and sick (group S; n = 51) foals, whereas in study 2, group H was divided into ...
Deng L, Li Z, Tang C, Han Y, Zhang L, Liao Q.Equine pregnancy is currently diagnosed by rectal palpation, ultrasonographic examination, or by measuring changes in hormones in the blood. In the present study, we identified proteins that are differentially expressed in the sera of early pregnant and non-pregnant mares in order to develop a novel method for diagnosing equine pregnancy. Serum samples were obtained from 18 adult mares, pregnancy at day 32 after ovulation (n = 9) and in diestrus (n = 9). Proteomic analysis of the samples was conducted using liquid chromatography-electrospray ionization-tandem mass spectrometry. We iden...
Macleay CM, Carrick J, Shearer P, Begg A, Stewart M, Heller J, Chicken C, Brookes VJ.Equine pregnancy loss is frustrating and costly for horse breeders. The reproductive efficiency of mares has significant implications for a breeding operation's economic success, and widespread losses can have a trickle-down effect on those communities that rely on equine breeding operations. Understanding the causes and risks of equine pregnancy loss is essential for developing prevention and management strategies to reduce the occurrence and impact on the horse breeding industry. This PRISMA-guided scoping review identified 514 records on equine pregnancy loss and described the global spatio...
Nielsen MK, Littman BA, Orzech SW, Ripley NE.Equine cyathostomins are ubiquitous in grazing horses around the world and a main target in parasite control programs. Anthelmintic resistance has been reported with increasing frequency in these parasites over the past decades, and recent findings of fulminant resistance to the macrocyclic lactone class have raised severe concerns. This study aimed to evaluate ivermectin efficacy in cohorts of yearlings and mares present on four different farms in Central Kentucky. Strongylid egg counts were determined with an automated egg counting system, and the percent fecal egg count reduction (FECR) was...
Renaudin CD, Kass PH, Bruyas JF.A table was generated, based on foetal ultrasonographic measurements in light breed mares, for each day of gestation beginning with day 100, to provide the predicted value of four biometric parameters: biparietal diameter (BPD), eye approximated volume (EyV), foetal aortic diameter (AortD) and femur length (FL). Using this table, day of gestation was successfully predicted in 23 Quarter Horses (QH) with known mating or ovulation dates. BPD, EyV and FL were the best foetal age predictors between 100- and 200-days gestation predicting within 2 weeks of the actual day of gestation, while BPD and...
Alberghina D, Statelli A, Monteverde V, Vazzana I, Cascone G, Panzera M.The values for basal serum cortisol concentrations of horses are available in many studies. However, there are limited data about serum cortisol in donkeys. The present study aimed to determine the baseline values for serum cortisol, to evaluate the influence of age and pregnancy on its levels, and to correlate its values with leucocyte profile, serum cholesterol, and triglycerides. Serum samples were collected from 97 healthy donkeys. Cortisol was analyzed by chemo-luminescent assay. The median and the 2.5th and 97.5th percentiles of serum cortisol measured and calculated in all donkeys were ...
Diel de Amorim M, Klein C, Foster R, Dong L, Lopez-Rodriguez MF, Card C.Leucyl and cystinyl aminopeptidase (LNPEP/oxytocinase) is an enzyme that metabolizes oxytocin in serum and tissues. The presence of oxytocin/neurophysin I (OXT), oxytocin and LNPEP and their relationship to other genes is unknown in the equine conceptus. Our objective was to characterize gene expression of LNPEP and OXT on D8, 10, 12, 14, 15, 16 and 21 conceptuses in relationship to other genes. Immunohistochemistry, western blot and liquid chromatography with tandem mass spectrometry (LC-MS/MS) were used for identification of oxytocin and LNPEP in D15, 16 and 18 conceptuses. LNPEP was increas...
Magalhaes HB, Canisso IF.This study aimed to establish normal ranges and determine variables affecting the duration of gestation, placental and fetal eyeball measurements in donkeys. Jennies (n = 121) were submitted to transrectal ultrasonography at 15-day-intervals from 120 days of gestation until parturition. During each examination, variables assessed included: the combined thickness of uterus and placenta (CTUP), fetal eyeball diameter, amniotic membrane thickness, allantoic and amniotic fluids echogenicity, and chorioallantois edema. Parametric data were analyzed with t-test, linear regression, mixed models, AN...
Donatsch L, Friker B, Sieme H, Kaeser R, Burger D.A potential source of fertility loss in mares is oviductal dysfunction, potentially caused by masses or debris in the lumen, that may prevent either sperm from reaching the fertilization site or the embryo from reaching the uterus. Recently a novel therapeutic method leading to increased pregnancy results was described by infusing misoprostol, a synthetic prostaglandin E, in the uterus of mares with unexplained fertility problems. In this study, we aimed, after examining the compatibility of misoprostol with semen, to evaluate the pregnancy rate after routine preovulatory deep uterine horn app...
Fanelli D, Tesi M, Monaco D, Diaz-Jimenez M, Camillo F, Rota A, Panzani D.In the literature, the very low pregnancy rates after artificial insemination (AI) with frozen semen in donkeys were improved in one study after re-extension of the frozen-thawed semen in autologous seminal plasma. The aims of our study were (1) to describe in vitro post-thaw parameters of donkey jackass semen after re-extension in seminal plasma (SP) or in INRA96 and (2) to compare pregnancy rates in jennies bred with frozen-thawed semen using two different AI protocols. Semen collected from two Amiata donkey stallions, known to be fertile, was frozen in INRA96 supplemented with 2% egg yolk, ...
Ginther OJ.Traveling of the fetal-amniotic unit throughout the uterus ceases on ∼ Day 180 followed by closure of each uterine horn. By mean Day 240, the fetus and nearly all of the pool of allantoic fluid are confined to the uterine body. Intrauterine fetal-location changes end, but in-place activity of limbs, head, and body and changes in fetal recumbency and presentation continue, sometimes vigorously. Preference for cranial presentation (fetal sternum toward maternal cervix) has been hypothesized to be stimulated by ∼ 40° incline of uterine body toward the cervix. The uterine body expands forward...
Hamond C, Pestana CP, Rocha-de-Souza CM, Cunha LE, Brandão FZ, Medeiros MA, Lilenbaum W.Leptospirosis is a zoonotic disease of global importance, and has a worldwide distribution. Equine leptospirosis is commonly manifested by recurrent uveitis, reproductive disorders, as abortions, embryonic absorption, stillbirth and the birth of weak foals. The aim of this study was to verify the presence of Leptospira sp or its DNA in genital tract of mares with reproductive problems. A total of 38 mares with reproductive problems were studied. All the mares were sampled for blood (for serology), urine (for culturing and qPCR), vaginal fluid-VF and endometrial biopsy-EB (for culturing, qPCR a...
Cochet M, Vaiman D, Lefèvre F.Interferons (IFNs) are cytokines of vertebrates with many biological effects including antiviral, immunoregulatory and antiproliferative activities. Among them, mammalian type I IFNs represents a large family of related proteins, mainly virus-inducible, divided in 10 distinct subfamilies named alpha, beta, omega, delta, epsilon, alphaomega, nu, tau, kappa and zeta (or Limitin). Some type I IFN subfamilies are physiologically expressed by the conceptus during early pregnancy in ungulates. This is the case in ruminants with IFN-tau (which triggers the maintenance of the maternal corpus luteum du...
Bazzano M, McLean A, Tesei B, Gallina E, Laus F.Selenium and vitamin E protect the body against oxidative stress. Clinical manifestations of their deficiency in equids include neurologic and muscular symptoms. Despite the importance of donkeys as working and production animals, there is a dearth of scientific data on selenium and vitamin E normal values. Therefore, the aim of this study was to investigate the plasma concentrations of selenium and vitamin E in healthy donkeys belonging to different ages, sexes, and productive phases. Animals were divided into five groups including foals (group A: n = 7, n = 4 males and n = 3 females), wea...
Klein C, Troedsson MH.Maternal recognition of pregnancy in the horse is the sum of events leading to maintenance of pregnancy; in a narrow sense, maternal recognition of pregnancy refers to the physiological process by which the lifespan of the corpus luteum is prolonged. The horse is one of the few domestic species in which the conceptus-derived pregnancy recognition signal has not been identified. The presence of the conceptus reduces pulsatile prostaglandin F(2α) secretion by the endometrium during early gestation in the mare, partly attributed to the reduced expression of cyclooxygenase-2. Cyclooxygenase-2 has...
Donaldson WL, Zhang CH, Oriol JG, Antczak DF.Monoclonal antibodies and alloantisera were used in an indirect immunohistochemical assay to determine the expression of class I and class II Major Histocompatibility Complex (MHC) antigens by equine placental cells and the endometrial tissues at the fetal-maternal interface. MHC class I antigens were expressed at high density on the surface of the trophoblast cells of the chorionic girdle at days 32-36, just prior to their invasion of the endometrium. The mature gonadotrophin-secreting cells of the endometrial cups, which are derived from the chorionic girdle cells, had greatly reduced levels...
Poonacha KB, Donahue JM, Giles RC, Hong CB, Petrites-Murphy MB, Smith BJ, Swerczek TW, Tramontin RR, Tuttle PA.Leptospirosis was diagnosed in 51 equine fetuses and 16 stillborn foals with gestational ages from 3 1/2 to 11 months. Diagnosis was based on one or more of the following: positive fetal antibody titer, positive fluorescent antibody test, demonstration of spirochetes in kidney and/or placental sections stained by the Warthin-Starry technique, high leptospiral titers in aborting mares, or isolation of Leptospira spp. from fetal organs. Gross lesions were observed in 80.3% of the fetuses, stillborn foals, and placentas. Gross placental lesions included nodular cystic allantoic masses, edema, are...
Sharp DC, Thatcher MJ, Salute ME, Fuchs AR.The effect of transcervical endometrial biopsy on the concentrations of plasma immunoreactive oxytocin and 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) was studied in 18 pony mares on days 8, 12 and 14 after ovulation, days 12 and 14 of early pregnancy and at oestrus. Five biopsy specimens were taken within 15 min and consecutive specimens from each mare were pooled two (A) and three (B) together for measurement of the number of oxytocin receptors. Blood samples were collected at intervals of 5 min for 15 min beginning just before the initial biopsy. Biopsy procedure elicited prompt oxy...
El-Sheikh Ali H, Dini P, Scoggin K, Loux S, Fedorka C, Boakari Y, Norris J, Esteller-Vico A, Kalbfleisch T, Ball B.Improved understanding of the molecular mechanisms underlying ascending equine placentitis holds the potential for the development of new diagnostic tools and therapies to forestall placentitis-induced preterm labor. The current study characterized the equine placental transcriptome (chorioallantois [CA] and endometrium [EN]) during placentitis (placentitis group, n = 6) in comparison to gestationally-matched controls (control group, n = 6). Transcriptome analysis identified 2953 and 805 differentially expressed genes in CA and EN during placentitis, respectively. Upstream regulator analys...
Legacki EL, Scholtz EL, Ball BA, Stanley SD, Berger T, Conley AJ.Liquid chromatography-tandem mass spectrometry (LC-MS/MS) allowed comprehensive analysis of various steroids detectable in plasma throughout equine gestation. Mares (n=9) were bled serially until they foaled. Certain steroids dominated the profile at different stages of gestation, clearly defining key physiological and developmental transitions. The period (weeks 6-20) coincident with equine chorionic gonadotropic (eCG) stimulation of primary corpora lutea and subsequent formation of secondary luteal structures was defined by increased progesterone, 17OH-progesterone and androstenedione, all ...
Bartolome Del Pino LE, Meana A, Zini M, Cersini A.Equine piroplasmosis (EP) is a vector borne disease caused by apicomplexans protists Babesia caballi (Nuttal et Strickland, 1910) and Theileria equi (Laveran, 1901). Carrier mares may transmit the infection transplacental resulting in neonatal piroplasmosis or abortions. This event has been described for T. equi by several authors over the world, but no evidence for B. caballi has been reported in Europe. In this study, vertical transmission for both parasites in an Italian breed mare has been confirmed using molecular and microscopic tools. Transplacental transmission is an underestimated pro...
Mariella J, Pirrone A, Gentilini F, Castagnetti C.The purposes of this study were to determine physiological changes occurring in hematologic and biochemical parameters in mares between the last month of gestation and the first week after parturition. If a significant change was observed with respect to the reference interval of an adult horse, a further aim of the study was to establish different reference intervals. Blood samples were collected from 62 healthy pregnant Standardbred mares. Seventeen nonpregnant and nonlactating mares were used as a control group. In pregnant mares, blood sampling was conducted every three days from 1 month b...
Nemoto M, Tsunemitsu H, Murase H, Nambo Y, Sato S, Orita Y, Imagawa H, Bannai H, Tsujimura K, Yamanaka T, Matsumura T, Kondo T.Both the G3P[12] and the G14P[12] type of equine group A rotavirus (RVA) have recently become predominant in many countries, including Japan. G3 types are classified further into G3A and G3B. The G3A viruses have been circulating in Europe, Australia, and Argentina, and the G3B viruses have been circulating in Japan. However, only an inactivated vaccine containing a single G3BP[12] strain is commercially available in Japan. To assess the efficacy of the current vaccine against recently circulating equine RVA strains, we examined antibody responses in pregnant mares to recent G3BP[12] and G14P[...
Wilsher S, Allen WR.The maternal recognition of pregnancy (MRP) signal in the mare has not been determined, although oestrogens have been proposed as a potential candidate. Objective: To determine effects of intrauterine administration of oestrogen and various oils on cyclic luteolysis in the mare. Objective: Intrauterine oestradiol or fatty acids may suppress luteolysis in the cycling mare when administered during late dioestrus. Methods: A single 1 ml dose of slow-release oestradiol (10 mg/ml) in fractionated coconut oil was infused into the uterine lumen of cycling mares on Days 6, 8, 10, 12 or 14 post ovulati...
Ellis WA, Bryson DG, O'Brien JJ, Neill SD.During an investigation of equine abortion, leptospiral infection was demonstrated in nine out of 22 foetuses examined by immunofluorescence and culture. Strains belonging to four serogroups (Australis, Pomona, Hebdomadis and Icterohaemorrhagiae) were isolated. The age of leptospira infected foetuses ranged from six months to term.
Serafini R, Longobardi V, Spadetta M, Neri D, Ariota B, Gasparrini B, Di Palo R.Aim of this study was to test the reliability of Trypan blue/Giemsa staining to evaluate sperm membrane integrity, acrosomal intactness and morphology in stallion to verify whether it could be applied in vitro as useful tool for sperm fertilizing ability. Fertility data on inseminated mares were collected to evaluate the relationship of sperm quality to pregnancy rates. Forty-one ejaculates were collected from 3 stallions of Salernitano Horse Breed and evaluated for gross appearance, volume, visual motility and membrane integrity with Trypan blue/Giemsa staining and thirty-five mares were inse...
Hagiwara K, Kamitani W, Takamura S, Taniyama H, Nakaya T, Tanaka H, Kirisawa R, Iwai H, Ikuta K.A pregnant mare showing pyrexia, reduced appetite, ataxia and paresis was euthanized and examined for the presence of Borna disease virus (BDV). Her brain, showing multiple neuronal degeneration and necrosis with hemorrhage, and the histologically normal brain of the fetus were both positive for BDV RNA. The BDV nucleotide sequences were identical in the mare and fetus in the second open reading frame (ORF). This is the first report of the possible vertical transmission of BDV in a horse.
Bazzano M, Giannetto C, Fazio F, Arfuso F, Giudice E, Piccione G.Pregnancy represents a specific physiological status characterized by continuous adjustments that affect maternal metabolism of all nutrients. In the last trimester of pregnancy, mare's nutrient requirements greatly increase and most pregnancy-associated diseases are likely to occur. Therefore, we aimed to assess the metabolic profile of broodmares focusing on the last 3 months of pregnancy and the early post-partum. Fifteen pregnant mares (Group A) were monitored from 263 ± 3 days of pregnancy until 21 days after foaling. Seven non-pregnant mares (Group B) were used as the control group...
Domino M, Borowska M, Kozłowska N, Zdrojkowski Ł, Jasiński T, Smyth G, Maśko M.Infrared thermography (IRT) was applied as a potentially useful tool in the detection of pregnancy in equids, especially native or wildlife. IRT measures heat emission from the body surface, which increases with the progression of pregnancy as blood flow and metabolic activity in the uterine and fetal tissues increase. Conventional IRT imaging is promising; however, with specific limitations considered, this study aimed to develop novel digital processing methods for thermal images of pregnant mares to detect pregnancy earlier with higher accuracy. In the current study, 40 mares were divided i...
Canisso IF, Carvalho GR, Morel MD, Ker PG, Rodrigues AL, Silva EC, Coutinho Da Silva MA.As mule production is often concentrated in remote areas of the world, a simplified semen cryopreservation protocol is required. Objective: To compare the seminal parameters of cryopreserved donkey semen in lactose-EDTA and lactose-yolk extenders and the fertility rates on horse mares. Methods: TRIAL 1: Sperm total and progressive motility, vigour (scale 0-5), morphology (major and minor defects) and plasma membrane integrity (HOST) were evaluated in 25 ejaculates from 5 donkey jacks immediately after collection (raw), after chilling to 5°C (chilled) and after freezing/thawing. The semen was ...
Crossett B, Allen WR, Stewart F.Large quantities of an unusual 19 kDa protein (p19) are secreted into the lumen of the uterus of the mare (Equus caballus) during the oestrous cycle and early pregnancy. p19 associates strongly with the acellular capsule that surrounds the young horse conceptus and is believed to be important in maintaining pregnancy. Here we report the complete cDNA sequence encoding p19, its expression patterns in horse tissues and a Southern blot analysis of the gene in horse DNA. The predicted amino acid sequence of the p19 cDNA demonstrated a signal peptide of 18 residues and a mature protein of 162 resid...
Adams-Brendemuehl C, Pipers FS.Measurements were made by real-time ultrasonography in 14 healthy mares to assess fetal growth and estimate newborn foal weights. Intrauterine fluid volumes were estimated and the placenta was measured and observed for maturational changes. The onset and incidence of echogenic particles in the allantoic fluid were recorded. In the second approach, baseline fetal heart rate, physiological rate variations and number, amplitude and duration of recorded accelerations were measured. Estimates of birth weights were within +/- 3.49 kg. Allantoic fluid was evident in all sonographic planes within the ...
Gambini A, Jarazo J, Olivera R, Salamone DF.The production of cloned equine embryos remains highly inefficient. Embryo aggregation has not yet been tested in the equine, and it might represent an interesting strategy to improve embryo development. This study evaluated the effect of cloned embryo aggregation on in vitro and in vivo equine embryo development. Zona-free reconstructed embryos were individually cultured in microwells (nonaggregated group) or as 2- or 3-embryo aggregates (aggregated groups). For in vitro development, they were cultured until blastocyst stage and then either fixed for Oct-4 immunocytochemical staining or maint...
Klein C."Maternal recognition of pregnancy" (MRP) is commonly used to describe the ongoing embryo-maternal communication during early pregnancy that culminates in prevention of luteolysis and ensures ongoing progestin support. The conceptus-derived pregnancy recognition signal has not yet been identified in the mare. Although equine conceptuses produce substantial amounts of estrogens, there is a lack of evidence that estrogens are the pregnancy recognition signal in mares. Conceptus mobility is integral to MRP and is driven by conceptus-derived prostaglandin production. Cessation of conceptus mobilit...
Kowalczyk A, Czerniawska-Piątkowska E, Kuczaj M.The purpose of this review was to analyze factors affecting the popularity of artificial insemination of mares in Europe in the context of sperm quality. Taking into account the prices of stallion semen on the world market, efficiency is important for the profitability of its use in artificial insemination programs in Europe. To increase the efficiency of a semen insemination facility, it is necessary to correctly and objectively assess the quality of semen. The available range of tools allows an effective evaluation of the potential fertility of a stallion. For several years, artificial insem...
Kayis SA, Atli MO, Kurar E, Bozkaya F, Semacan A, Aslan S, Guzeloglu A.The aim was an evaluation of a set of housekeeping genes (HKGs) to be used in the normalization of gene expression in the equine endometrium. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), hypoxanthine ribosyl transferase 1 (HPRT1), ubiquitin B (UBB), tubulin alpha 1 (TUBA1), ribosomal protein L32 (RPL32), beta-2-microglobulin (B2M), 18S rRNA (18S), and 28S rRNA (28S) HKGs were evaluated using real-time PCR and were compared in different physiological stages of the endometrium. Endometrial biopsies were obtained from mares on day of ovulation (d0, n=4), at late diestrus (LD, n=4), after lut...
Oriol JG, Sharom FJ, Betteridge KJ.The embryonic capsule, which covers the equine blastocyst after it loses its zona pellucida, is composed of mucin-like glycoproteins. In the present study, we investigated both macroscopic and molecular changes in the capsule during development. The weight of the capsule increased from day 11-12 of pregnancy and reached a maximum at about day 18, coinciding with the time during which the conceptus migrates extensively throughout the uterus. The sialic acid content of the capsule declined markedly from about day 16, the time of conceptus 'fixation' in the uterus, which suggests a unique develop...
Nolan MB, Walsh CM, Duff N, McCrarren C, Prendergast RL, Murphy BA.In seasonally breeding animals, photoperiod perception is crucial for timing of important physiological events. In the horse, long day photoperiod influences the onset of ovulation and cyclicity, shedding of the heavier winter coat and the timing of parturition. In this compilation of studies, conducted across three breeding seasons and two countries, the impact of artificially extended day length was investigated on gestation length, foal birth weight and foal hair coat at birth. The light therapy was administered to pre-partum mares via mobile head worn masks which provided short wavelength ...
Aurich C, Schneider J.In the equine species, sex determination of the conceptus is of growing interest for the breeding industry. In horses, the sex ratio of the offspring depends on changes in body condition of the mother at conception and under natural conditions may thus markedly deviate from an expected 1:1 ratio. Insemination with sex-sorted spermatozoa allows a pronounced shift of the sex ratio but at present pregnancy rates are low and vary considerably under field conditions. In equine embryo transfer programmes, sex determination in embryos before transfer via genetic methods is a promising approach with h...
Carnevale EM, Coutinho da Silva MA, Panzani D, Stokes JE, Squires EL.Oocyte transfer is a potential method to produce offspring from valuable mares that cannot carry a pregnancy or produce embryos. From 2000 through 2004, 86 mares, 19.2 +/- 0.4 yr of age (mean +/- S.E.M.), were used as oocyte donors in a clinical program at Colorado State University. Oocytes were collected from 77% (548/710) of preovulatory follicles and during 96% (548/570) of cycles. Oocytes were collected 21.0+/-0.1h after administration of hCG to estrous donors and cultured 16.4 +/- 0.2 h prior to transfer into recipients' oviducts. At 16 and 50 d after transfer, pregnancies were detected i...
Klein C, Troedsson MH, Rutllant J.The expression of 12 different aquaporin subtypes in equine endometrium was examined at the mRNA and protein level. Endometrial samples were obtained during anoestrus, oestrus, 8, and 14 days after ovulation in non-pregnant mares, and 14 days after ovulation in pregnant mares. Quantitative PCR revealed a time-dependent pattern for all aquaporin subtypes examined except for AQP10 and 12. AQP3, 5 and 7 showed highest mRNA abundance 8 days after ovulation, while AQP0 and 2 were most abundant at Day 14 of the cycle in non-pregnant mares. At 14 days of pregnancy, AQP1, 4, 8, 9 and 11 displayed ...
