Reproduction in horses encompasses the biological processes and mechanisms involved in the breeding and development of equine offspring. This includes the study of reproductive anatomy, physiology, and endocrinology in both mares and stallions. Key areas of interest include the estrous cycle, ovulation, conception, gestation, and parturition. Researchers also examine factors influencing fertility, reproductive technologies such as artificial insemination and embryo transfer, and management practices that impact reproductive success. This page compiles peer-reviewed research studies and scholarly articles that explore the physiological, genetic, and environmental aspects of equine reproduction.
Catalán J, Yánez-Ortiz I, Tvarijonaviciute A, González-Arostegui LG, Rubio CP, Yeste M, Miró J, Barranco I.This study investigated whether the activities of the antioxidant components of donkey seminal plasma (SP)-both enzymatic (superoxide dismutase (SOD), catalase-like (CAT), glutathione peroxidase-like (GPX), and paraoxonase type 1 (PON1)) and non-enzymatic (measured in terms of total thiol, copper-reducing antioxidant capacity (CUPRAC), ferric-reducing ability of plasma (FRAP), and Trolox equivalent antioxidant capacity (TEAC))-and oxidative stress index (OSI) are related to sperm cryotolerance. For this purpose, 15 ejaculates from jackasses (one per individual) were collected and split into tw...
Lawson EF, Grupen CG, Baker MA, Aitken RJ, Swegen A, Pollard CL, Gibb Z.Lipids are dynamic biological molecules that play key roles in metabolism, inflammation, cell signalling and structure. They are biologically significant in the physiology of conception and reproduction. Many of the mechanisms surrounding equine conception and the early feto-maternal dialogue are yet to be understood at a biochemical level. Recently, lipidomic technologies have advanced considerably and analytical strategies have been enhanced and diversified. Consequently, in-depth lipidomic exploration now has the potential to reveal new lipid biomarkers and biochemical relationships that im...
Mainguy-Seers S, Diaw M, Lavoie JP.While the prevalence of asthma is higher in boys than in girls during childhood, this tendency reverses at puberty, suggesting an effect of sex hormones on the disease pathophysiology. Fluctuations of asthma severity concurring with the estrus cycle are reported in women, but this phenomenon has never been investigated in mares to date. The objective of this exploratory study was to determine whether the estrus cycle modulates airway obstruction in severe equine asthma (SEA). Five mares with SEA during exacerbation of the disease were studied. The whole breath, expiratory and inspiratory resis...
Laseca N, Molina A, Ramón M, Valera M, Azcona F, Encina A, Demyda-Peyrás S.The loss of genetic variability in livestock populations bred under strict selection processes is a growing concern, as it may lead to increased inbreeding values and lower fertility, as a consequence of the "inbreeding depression" effect. This is particularly important in horses, where inbreeding levels tend to rise as individuals become more and more closely related. In this study, we evaluated the effect of increased inbreeding levels on mare fertility by combining an SNP-based genomic approach using runs of homozygosity and the estimation of genetic breeding values for reproductive traits ...
Piotrowska-Tomala KK, Jonczyk AW, Szóstek-Mioduchowska AZ, Żebrowska E, Ferreira-Dias G, Skarzynski DJ.We examined the effect of prostaglandin (PG) E on the secretory function of equine corpus luteum (CL), according to the application site: intra-CL injection vs. an intrauterine (intra-U) administration. Moreover, the effect of intra-CL injection vs. intra-U administration of both luteotropic factors: PGE and human chorionic gonadotropin (hCG) as a positive control, on CL function was additionally compared. Mares were assigned to the groups ( = 6 per group): (1) an intra-CL saline injection (control); (2) an intra-CL injection of PGE (5 mg/ml); (3) an intra-CL injection of hCG (1,500 IU/ml); (4...
Loux S, Robles M, Chavatte-Palmer P, de Mestre A.Development and the subsequent function of the fetal membranes of the equine placenta require both complex and precise regulation of gene expression. Advancements in recent years in bioinformatic techniques have allowed more extensive analyses into gene expression than ever before. This review starts by combining publically available transcriptomic data sets obtained from a range of embryonic, placental and maternal tissues, with previous knowledge of equine placental development and physiology, to gain insights into key gene families relevant to placentation in the horse. Covering the whole o...
Robles M, Loux S, de Mestre AM, Chavatte-Palmer P.Equine placental development is a long process with unique features. Implantation occurs around 40 days of gestation (dpo) with the presence of a transient invasive placenta from 25-35 to 100-120 dpo. The definitive, non-invasive placenta remains until term (330 days). This definitive placenta is diffuse and epitheliochorial, exchanging nutrients, gas and waste with the endometrium through microvilli, called microcotyledons. These are lined by an external layer of haemotrophic trophoblast. Moreover, histotrophic exchange remains active through the histotrophic trophoblast located along the are...
Pruß D, Oldenhof H, Wolkers WF, Sieme H.The aim of this study was to establish an alginate encapsulation procedure for stallion sperm, and investigate if sperm encapsulation enhances longevity during cold storage and survival after cryopreservation. First, biocompatibility of the compounds needed for encapsulation was tested and factors determining capsule structure were identified. Sperm encapsulation was realized either by depositing droplets (20 µL) of sperm solution supplemented with barium or calcium chloride (10 mM) in alginate solution (0.25%, w/v), or by adding sperm-alginate droplets in solution containing barium or calc...
Huricha , Kawai M, Ninomiya S.In this study, we investigated suckling behavior and the distance between a foal and its mare as indicators of foal growth in Hokkaido native horses (HKD) during the first 40 days of life. Direct observations were made of 22 mare and foal pairs from two consecutive days 1 and 2, 5 and 6, 10 and 11, 20 and 21, 30 and 31, and 40 and 41 after birth by focal animal sampling for 3 h per day. Suckling behavior was continuously recorded, along with the terminator. The distance between the foal and its mare was determined using the instantaneous sampling method (1 min), and the percentage was calc...
Cabral LDR, Sato AP, de Sousa RS, Rossa AP, Sanches AWD, Bortoleto CT, Locatelli Dittrich R.The closely related apicomplexa protozoa, Toxoplasma gondii, Neospora spp., and Sarcocystis neurona, have all been associated with neurological and reproductive diseases in horses. However, there is limited data regarding the presence of these three parasites in equine placental tissues and amniotic fluid. The aim of the present report was to investigate the presence of the DNA of T. gondii, Neospora spp. and S. neurona in placentas and amniotic fluid in mares. Anti-T. gondii, anti- S. neurona and anti- Neospora spp. antibody titers were evaluated in 31 mares in the final third of pregnancy by...
Nichols JL, Robinson JS, Hiney KM, Terry R, Ramsey JW.This study investigated equine nutrition knowledge and educational needs of licensed veterinarians in the United States who were exclusively or predominately equine practitioners. It found veterinarians regard their peers as an important resource of nutritional knowledge, ranking ahead of all other sources except a PhD equine nutritionist. Interestingly, only 21% of veterinarians felt good about their knowledge level in equine nutrition after graduating from veterinary school. Although veterinarians in this study reported equine nutrition to be an area of weakness, 75% had not pursued continui...
Oberhaus EL, Wilson KM, Camp CM, Sones JL.Sulpiride in vegetable shortening (VS) stimulates prolactin in horses for up to 10 days. Although effective, a pharmaceutical grade vehicle is needed for clinical application of sulpiride in horses. Sucrose acetate isobutyrate (SAIB), a hydrophobic polymer, may be an alternative to VS. Four in vivo experiments assessed the efficacy of SAIB for delivery of sulpiride, estradiol cypionate (ECP), and estradiol benzoate (EB). The first three studies utilized geldings to compare prolactin and luteinizing hormone (LH) concentrations between sulpiride delivered in VS and SAIB, and ECP or EB delivered ...
Grillaert K.Erection and masturbation in horses are considered unwanted behaviors in training contexts, despite recognition that these are naturally occurring behaviors that are integral to the welfare of male horses. Equestrians, especially those who use positive reinforcement in their training, expressed concern that the presence of such behaviors might be associated with aggressive or sexual behaviors aimed at humans participating in horse-human interactions. The implications of such attitudes could negatively affect male horses by excluding them from welfare-friendly training systems. In this study, f...
Thomson K, Eskola K, Eklund M, Suominen K, Määttä M, Junnila J, Nykäsenoja S, Niinistö K, Grönthal T, Rantala M.Extended-spectrum β-lactamase producing Enterobacterales (ESBL-E) are important causative agents for infections in humans and animals. At the Equine Veterinary Teaching Hospital of the University of Helsinki, the first infections caused by ESBL-E were observed at the end of 2011 leading to enhanced infection surveillance. Contact patients were screened for ESBL-E by culturing infection sites and rectal screening. This study was focused on describing the epidemiology and microbiological characteristics of ESBL-E from equine patients of the EVTH during 2011-2014, and analysing putative risk fac...
Ginther OJ.Intrauterine mobility of the fetal-amniotic unit is unique in equids among domestic species. Intrinsic activity begins as head nods on ∼ Day 40 (Day 0 = ovulation) and by Day 60 has progressed into intermittent subtle to vigorous head, neck, limb, and body movements. On Days 60-100, fetal mobility is maximal with traveling of the fetal-amniotic unit throughout an allantoic pool that encompasses the uterine horns, and uterine body. The fetus may be entirely within one uterine horn with the horn entrance closed behind it, and then may work through the entrance into the uterine body. Mobility...
Zhao Y, Zhu Y, Liu B, Mi J, Li N, Zhao W, Wu R, Holyoak GR, Li J, Liu D, Zeng S, Wang Y.Endometritis is a common reproductive disease in equine animals. No investigation about the bacterial characteristics and antimicrobial susceptibility pattern of donkeys with endometritis has thus far been reported. Objective: To determine the common uterine bacterial isolates from donkeys with endometritis and to evaluate their susceptibility to antimicrobials used for the treatment thereof. Methods: Retrospective case-series. Methods: Medical records at an equine clinical diagnostic center were retrospectively reviewed to identify submissions from donkeys with bacterial endometritis between ...
Moore T, Williams JM, Becerra-Rodriguez MA, Dunne M, Kammerer R, Dveksler G.Pregnancy-specific glycoproteins (PSGs) are members of the immunoglobulin superfamily and are closely related to the predominantly membrane-bound CEACAM proteins. PSGs are produced by placental trophoblasts and secreted into the maternal bloodstream at high levels where they may regulate maternal immune and vascular functions through receptor binding and modulation of cytokine and chemokine expression and activity. PSGs may have autocrine and paracrine functions in the placental bed, and PSGs can activate soluble and extracellular matrix bound TGF-β, with potentially diverse effects on multip...
Domingues RR, Ginther OJ, Gomez-Leon V, Castro T, Wiltbank MC.In heifers and mares, multiple pulses of prostaglandin F2alpha (PGF) are generally associated with complete luteal regression. Although PGF pulses occur before and during luteolysis, little is known about the role of minor PGF pulses during preluteolysis on subsequent luteal and endometrial PGF production that may initiate luteolysis. Heifers (n = 7/group) and mares (n = 6/group) were treated with a single minor dose of PGF (3.0 and 0.5 mg, respectively) during mid-luteal phase (12 and 10 days postovulation respectively). After treatment, a transient decrease in progesterone (P4) con...
Monteiro RA, Cunha RM, Guerra MMP, de Almeida VM, Peña-Alfaro CE, Silva SV.The aim of this study was to test equine semen cryopreservation techniques for the conservation of donkey germplasm. Ejaculates of three male donkeys were used (n = 18; six ejaculates per donkey; six repetitions), collected by the artificial vagina method. To remove the seminal plasma, the ejaculates were split and submitted to filtration or centrifugation methods. To assess the freezing method, each fraction was submitted to the automated system or the conventional system, and groups were formed: automated centrifuge, automated filtrate, conventional centrifuge and conventional filtrate. Af...
Castro T, Jacob JC, Domingues RR, Ginther OJ.Prostaglandin E2 (PGE2) and prostaglandin F2α (PGF2α) are involved in equine embryo mobility throughout the uterus on Days 11-15 (ovulation = Day 0). On a day (Day 12) of maximal embryo mobility in pregnant mares (n = 13) and before luteolysis in nonbred mares (n = 10), gene expressions were compared between the uterine horns that did and did not contain the mobile embryo and between pregnant and nonbred mares. A cytobrush was used to collect an endometrial sample from the middle of each uterine horn. In nonbred mares, there was no difference for any of the considered gene expressions ...
Catandi GD, LiPuma L, Obeidat YM, Maclellan LJ, Broeckling CD, Chen T, Chicco AJ, Carnevale EM.Dietary supplementation is the most feasible method to improve oocyte function and developmental potential . During three experiments, oocytes were collected from maturing, dominant follicles of older mares to determine whether short-term dietary supplements can alter oocyte metabolic function, lipid composition, and developmental potential. Over approximately 8 weeks, control mares were fed hay (CON) or hay and grain products (COB). Treated mares received supplements designed for equine wellness and gastrointestinal health, flaxseed oil, and a proprietary blend of fatty acid and antioxidant s...
Holyoak GR, Ma A.Historical evidence of acupuncture predates written history. It has been a component of Traditional Chinese veterinary medicine for many generations and is officially recognized in recorded history for treating equine disease in the Zhou Dynasty, circa 1050 BC. Drawing from a range of searchable databases, we present the use of veterinary acupuncture related to theriogenology. We touch on human-based medicine only as an introduction to current uses within veterinary medical acupuncture. This review is confined to the use of acupuncture encompassing dry needle, electroacupuncture, aquapuncture,...
Lançoni R, Celeghini ECC, Gonella-Diaza AM, Júnior VG, de Carvalho CPT, Zoca GB, Garcia-Oliveros LN, Batissaco L, Oliveira LZ, de Arruda RP.This study aimed to assess the semen ubiquitin levels of stallions with good (GF) and poor semen freezability (PF) and to evaluate the relationship between sperm ubiquitination and sperm morphological defects. Five ejaculates from eight adult stallions (n = 40) were collected and cryopreserved. Then, the ubiquitin level in equine sperm cells was assessed by immunohistochemistry with epifluorescence microscopy, and sperm morphology was assessed by differential interference contrast microscopy. Sperm cells were classified according to the intensity (classification 1: from I to IV; I = very l...
Straticò P, Guerri G, Palozzo A, Varasano V, Petrizzi L.(1) Background: Laparoscopic surgery replaced traditional invasive techniques for the treatment of common urogenital disorders in equids. The aim of this review is to evaluate applications and the development of urogenital laparoscopy from 2001 to 2021. (2) Methods: A scoping review of literature was undertaken according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines for scoping reviews on three databases (NCBI-PubMed, Web of Science-Thompson Reuters, and SciVerse Scopus). (3) Results: A total of 452 papers were identified. After duplicate removal...
Fernández-Hernández P, García-Marín LJ, Bragado MJ, Domingo A, González-Fernández L, Macías-García B.In the horse, a repeatable protocol for in vitro fertilization has not been developed, possibly due to incomplete sperm capacitation. We have previously identified the metabolites present in equine oviductal fluid (OF). We aimed to test the effects of different metabolites found in equine oviductal fluid on quality parameters of frozen-thawed spermatozoa. Different concentrations of myoinositol (5-25 mM), lactate (6-60 mM), glycine (0.1-5 mM), β-alanine (1-6 mM), and histamine (0.05-0.4 mM) were added independently to modified Whitten's medium (pH = 7.25). Thawed equine spermatozoa (three s...
Ablondi M, Johnsson M, Eriksson S, Sabbioni A, Viklund ÅG, Mikko S.Warmblood fragile foal syndrome (WFFS) is a monogenetic defect caused by a recessive lethal missense point mutation in the procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 gene (PLOD1, c.2032G>A). The majority of homozygous WFFS horses are aborted during gestation. Clinical signs of affected horses include fragile skin, skin and mucosa lacerations, hyperextension of the articulations, and hematomas. In spite of its harmful effect, a relatively high frequency of WFFS carriers has been found in Warmblood horses, suggesting a heterozygote advantage. Thus, in this study our aims were to: (1) est...
Briski O, Salamone DF.During the past 2 decades, intracytoplasmic sperm injection (ICSI) has become a routine technique for clinical applications in humans. The widespread use among domestic species, however, has been limited to horses. In horses, ICSI is used to reproduce elite individuals and, as well as in humans, to mitigate or even circumvent reproductive barriers. Failures in superovulation and conventional in vitro fertilization (IVF) have been the main reason for the use of this technology in horses. In pigs, ICSI has been successfully used to produce transgenic animals. A series of factors have resulted in...
Ibrahim S, Hedia M, Taqi MO, Derbala MK, Mahmoud KGM, Ahmed Y, Sosa AS, Saber YHA, Hasanain MH, Nawito MF, Seidel GE.Extracellular vesicles (EVs) are a promising biomarker and play a vital role in cell-cell communication. This study aimed (I) to identify and characterize EVs from low volume uterine lavage (LVL) and serum in mares with endometritis, compared to healthy controls and (II) to measure serum levels of interleukin 6 (IL-6), and prostaglandins (PGF and PGE). Mares were divided into 30 sub-fertile (endometritis) and 20 fertile (controls). Serum and LVL was collected for EV isolation, and determination of serum levels of inflammatory mediators. Characterization and visualization of EVs were done by el...
Griffin RA, Swegen A, Baker MA, Ogle RA, Smith N, Aitken RJ, Skerrett-Byrne DA, Fair S, Gibb Z.Stallions experience transient fluctuations in fertility throughout the breeding season. Considering pregnancy diagnoses cannot be ascertained until ~14 days postbreeding, the timely detection of decreases in stallion fertility would enhance industry economic and welfare outcomes. Therefore, this study aimed to identify the proteomic signatures reflective of short-term fertility fluctuations and to determine the biological mechanisms governing such differences. Using liquid chromatography-mass spectrometry (LC-MS/MS), we compared the proteomic profile of semen samples collected from commercia...
Ousey JC.The endocrine profiles in the periparturient mares are dominated by increasing concentrations of progestagens and decreasing oestrogens. These hormones are produced by precursors from the foetus, metabolized by the placenta and act primarily on the maternal uterus. The circulating concentrations of hormones in maternal plasma, generally, represent a small proportion of those metabolized by the foetus and utero-placental tissues. There is clear evidence that the foetal hypothalamo-pituitary-adrenal (HPA) axis initiates the process of foetal maturation and the hormonal cascade which culminates i...
Morris LHA.The development of techniques to produce equine embryos in vitro is reviewed with specific reference to intracytoplasmic sperm injection (ICSI). Unexplored 50 years ago, this technology has progressed rapidly in the last 20 years to become a commercial reality for the equine breeding industry. Improvements in our understanding of oocyte and embryo competence in the horse have been key factors in overcoming some of the initial problems associated with ICSI. It is now possible to obtain high nuclear maturation and cleavage rates in vitro and the most limiting factor, presently, is the low rate o...
Sairanen J, Nivola K, Katila T, Virtala AM, Ojala M.The Finnish mating records of Standardbred trotters (SB; n = 33 679) and Finnhorses (FH; n = 32 731) were analysed to study the effect of the level of inbreeding on foaling rates and to estimate the heritability of foaling rate. A linear mixed model was assumed, with the outcome of the foaling (foal or no foal) as the trait of the study. A restricted maximum likelihood-based method was used to calculate the estimates of the variance components. Predictions of breeding values and estimates of fixed effects were also calculated. The average level of inbreeding was 9.9% in the SB and 3.6% in the ...
Salgado RM, Brom-de-Luna JG, Resende HL, Canesin HS, Hinrichs K.The aim of this study was to evaluate the differential effects of conventional and Piezo-driven ICSI on blastocyst development, and on sperm component remodeling and oocyte activation, in an equine model. Methods: In vitro-matured equine oocytes underwent conventional (Conv) or Piezo ICSI, the latter utilizing fluorocarbon ballast. Blastocyst development was compared between treatments to validate the model. Then, oocytes were fixed at 0, 6, or 18 h after injection, and stained for the sperm tail, acrosome, oocyte cortical granules, and chromatin. These parameters were compared between inject...
Atli MO, Guzeloglu A, Dinc DA.WNT signaling pathway plays important roles in reproductive events. Aims were to (1) determine presence of WNT genes and their antagonists in equine endometrium; and (2) to evaluate their expression profiles during early pregnancy. Endometrial biopsies were obtained from mares on day of ovulation (d0, n=4) and on days of 14 (P14, n=4), 18 (P18, n=4), 22 (P22, n=4) of early pregnancy. Biopsies were also collected from cyclic mares during late diestrus (LD, on day of 13.5-14, n=4) and after luteolysis in estrus phase (AL, on day of 17.5-18, n=4) of the cycle. PCR was used to detect expression of...
Buczkowska J, Kozdrowski R, Nowak M, Raś A, Staroniewicz Z, Siemieniuch MJ.Endometritis is a major cause of infertility in the mare. Therefore, the diagnosis of this disease is very important in veterinary practice. The objective of this study was to compare bacteriological and cytological results obtained from the mare uterus using biopsy (EB) and cytobrush (CB) techniques and relating these findings to the presence of polymorphonuclear cells (PMNs) in endometrial tissue as the gold standard for detection of endometritis. In particular, we tested the hypothesis that endometrial cytology and microbiology data obtained from material collected using the EB and CB techn...
Johnson L, Thompson DL.Testes and blood samples were obtained from 201 stallions aged 6 months to 20 years in either December-January (nonbreeding season) or June-July (breeding season) to study the effect of age and season on reproductive parameters. Seasonal differences in the Sertoli cell population of adult (4-20 years old) horses were characterized by a 36% larger number of Sertoli cells in the breeding season than in the nonbreeding season. Seasonal elevation in the Sertoli cell population was associated with an increase in testicular weight and daily sperm production per testis (DSP/testis). Concentrations of...
Davies Morel MC, Newcombe JR, Holland SJ.In order to assist in the accurate prediction of the timing of parturition in the mare true gestation length, along with the potential effect of a number of factors, was investigated. Data from 433 Thoroughbred foal pregnancies were used. Sequential ultrasonic scanning allowed the true gestation length (fertilisation-parturition) to be ascertained, as apposed to previous work, which used the mating-parturition interval. An average gestation length of 344.1 +/- 0.49 days was evident. Colt foal pregnancies were significantly (P < 0.001) longer (346.2 +/- 0.72) than fillies (342.4 +/- 0.65). Mont...
Sostaric E, Aalberts M, Gadella BM, Stout TA.The epididymis is a long, tightly coiled tube within the lumen of which sperm matures. Sperm maturation involves morphological and biochemical changes in the sperm plasma membrane in response to epididymal secretions and their various proteins. Some of these proteins become outer membrane components while others become integral membrane proteins; transfer of some proteins to the sperm plasma membrane may be mediated by epididymosomes. Nevertheless, the molecular pathways by which spermatozoa acquire fertilizing capacity during their transit through the epididymis remain ambiguous. In a recent ...
Morrell JM, Dalin AM, Rodriguez-Martinez H.A new, simpler, technique of colloidal centrifugation has recently been developed, designated single layer centrifugation (SLC). This technique requires evaluation by comparison with a density gradient for its ability to select the best quality spermatozoa and its practicality of use on studfarms. Objective: To compare the effect of 2 methods of colloidal centrifugation, density gradient centrifugation and single layer centrifugation, on stallion sperm motility, yield and survival, using freshly collected extended stallion semen. Methods: Aliquots of extended stallion semen from 10 stallions (...
Rink BE, Beyer T, French HM, Watson E, Aurich C, Donadeu FX.Because of their distinct differentiation, immunomodulatory, and migratory capacities, endometrial mesenchymal stromal cells (MSCs) may provide an optimum source of therapeutic cells not only in relation to the uterus but also for regeneration of other tissues. This study reports the fate of endometrial MSCs following intrauterine application in mares. Stromal cell fractions were isolated from endometrial biopsies taken from seven reproductively healthy mares, expanded, and fluorescence labeled in culture. Phosphate-buffered saline (PBS) or MSCs (15 × 10) were autologously infused into ea...
Troedsson MH, Liu IK, Crabo BG.Following the deposition of semen in the mares uterus, spermatozoa must be transported to the site of fertilization, be maintained in the female tract until ovulation occurs, and be prepared to fertilize the released ovum. Sperm motility, myometrial contractions, and a spontaneous post-mating uterine inflammation are important factors for the transport and survival of spermatozoa in the mares reproductive tract. Fertilizable sperm are present in the oviduct within 4 hours after insemination. At this time, the uterus is the site of a hostile inflammatory environment. Our data suggest that sperm...
Holyoak GR, Little TV, McCollam WH, Timoney PJ.The relationship between stage of reproductive tract maturity and susceptibility to the experimental establishment of persistent infection with equine arteritis virus (EAV) was investigated in 21 prepubertal and 15 peripubertal colts. Five of six prepubertal colts inoculated intranasally remained infected in the reproductive tract from post-challenge day 28 to 93 and two of six from post-challenge day 120 to 180. No virus was detected in five of these animals killed on post-challenge day 210. Each of two peripubertal colts remained infected in the reproductive tract at post-challenge day 60 an...
Knott LE, Fonseca-Martinez BA, O'Connor AM, Goodrich LR, McIlwraith CW, Colbath AC.To evaluate the use of mesenchymal stem cells (MSCs), autologous conditioned serum (ACS), platelet-rich plasma (PRP), and autologous protein solution (APS) for the treatment of equine musculoskeletal disease by diplomates of the American College of Veterinary Surgery (ACVS), and American College of Veterinary Sports Medicine and Rehabilitation (ACVSMR). Methods: Cross-sectional study. Methods: Diplomates (n = 423). Methods: An email link was sent to ACVS and ACVMR diplomates. A survey contained 59 questions regarding demographics, as well as indications, frequency, adverse effects, and limit...
Sarkar DK, Smith GC, Fink G.We have investigated the effect of manipulating central catecholamines on the timing of puberty (as assessed by vaginal opening) in female rats and the surge of luteinizing hormone (LH) and gonadotropin releasing hormone (GnRH) induced by pregnant mare serum gonadotropin (PMSG) in immature female rats. Manipulation of the catecholamines was carried out with either 6-hydroxydopamine (6-OHDA) administered with or without either desipramine (DMI) or pargyline, or alpha-methyl-p-tyrosine (alpha-MPT). The neonatal administration of 6-OHDA delayed puberty, an effect which was potentiated by pretreat...
Campbell ML.Veterinarians have a key role in providing medical care for sports horses during and between competitions, but the standard client:veterinarian relationship that exists in companion and production animal medicine is distorted by the involvement of third parties in sports medicine, resulting in distinct ethical dilemmas which warrant focused academic attention. By comparing the existing literature on human sports medicine, this article reviews the ethical dilemmas which face veterinarians treating equine athletes, and the role of regulators in contributing to or resolving those dilemmas. Major ...
DARLINGTON RW, RANDALL CC.Equine abortion virus was purified from the plasma of infected golden Syrian hamsters by differential centrifugation and nuclease treatment. The preparations were essentially free of nonviral elements on electron microscopic examination, and sedimentation in sucrose and potassium tartrate density gradients resulted in a single visible band. Electron microscopy of this band showed it to be composed of viral particles, and injection into hamsters resulted in infection and death of the animals. The viral particles had a sedimentation coefficient of approximately 2200 S and a hydrated density of 1...
Burnaugh L, Ball BA, Sabeur K, Thomas AD, Meyers SA.The objective of this study was to examine the interplay between osmotic and oxidative stress as well as to determine mechanisms by which osmotic stress increases superoxide generation in spermatozoa of horses. Superoxide production, as measured by dihydroethidium (DHE), increased when spermatozoa of horses were incubated under either hyperosmotic or hyposmotic conditions. This increase in superoxide production was inhibited by the MAP kinase p38 inhibitor, SB203580, and by the superoxide scavenger, tiron. Incubation of spermatozoa under hyperosmotic conditions increased overall protein tyrosi...
Altermatt JL, Suh TK, Stokes JE, Carnevale EM.Young (4 to 9 yr) and old (>or=20 yr) mares were treated with equine follicle-stimulating hormone (eFSH), and oocytes were collected for intracytoplasmic sperm injections (ICSI). Objectives were to compare: (1) number, morphology and developmental potential of oocytes collected from young v. old mares from cycles with or without exogenous eFSH and (2) oocyte morphology parameters with developmental competence. Oocytes were collected from preovulatory follicles 20 to 24 h after administration of recombinant equine LH and imaged before ICSI for morphological measurements. After ICSI, embryo d...
Dhakal P, Hirama A, Nambo Y, Harada T, Sato F, Nagaoka K, Watanabe G, Taya K.The present study was conducted to elucidate the profile of circulating gonadotropins and gonadal hormones from birth to puberty and relationship between gonadal seasonality and hormonal secretion in both sexes of Thoroughbred horses. Spring-born colts (n=6) and fillies (n=9) were blood sampled weekly from jugular vein from birth to 60 weeks of age. Circulating FSH, LH, prolactin, testosterone, progesterone, estradiol-17β, and immunoreactive (ir)-inhibin were measured by radioimmunoassay. In both sexes, the steroid hormones levels were remarkably high at birth, rapidly dropped within a week a...
Gérard N, Delpuech T, Oxvig C, Overgaard MT, Monget P.In the ovary of mammalian species, terminal follicular growth is accompanied by a decrease in intrafollicular levels of IGF-binding protein-2 (IGFBP-2) and IGFBP-4. The decrease in IGFBP-4 levels is essentially due to an increase in proteolytic cleavage by intrafollicular pregnancy-associated plasma protein-A (PAPP-A) in growing healthy follicles. The decrease in IGFBP-2 levels is partly due to a decrease in mRNA expression by follicular cells. In addition, we have recently shown that IGFBP-2 is also proteolytically cleaved by PAPP-A in bovine and porcine growing follicles. In the present work...
García BM, Moran AM, Fernández LG, Ferrusola CO, Rodriguez AM, Bolaños JM, da Silva CM, Martínez HR, Tapia JA, Peña FJ.Cryopreservation introduces extreme temperature and osmolality changes that impart lethal and sublethal effects on spermatozoa. Additionally, there is evidence that the osmotic stress induced by cryopreservation causes oxidative stress to spermatozoa. The main sources of reactive oxygen species in mammalian sperm are the mitochondria. In view of this, the aim of our study was to test whether or not osmotic stress was able to induce mitochondrial damage and to explore the osmotic tolerance of the mitochondria of stallion spermatozoa. Ejaculates from 7 stallions were subjected to osmolalities ra...
The Journal of heredityMay 1, 1984
Volume 75, Issue 3 220-224 doi: 10.1093/oxfordjournals.jhered.a109916
Cothran EG, MacCluer JW, Weitkamp LR, Pfennig DW, Boyce AJ.The relationship between inbreeding and both conception and foaling rates in Standardbred horses (trotters and pacers) was examined for 1194 breeding years. There was a statistically significant (P less than 0.05) trend for conception and foaling rates to decrease with increased inbreeding; however, this relationship accounted for less than 2 percent of the variation. Additionally, the relationship between reproductive performance and inbreeding was not consistent between trotters and pacers. For trotters (F = 0.103) there was a trend for an increase in conception and foaling rates with increa...
de Mestre AM, Rose BV, Chang YM, Wathes DC, Verheyen KLP.Early pregnancy loss (EPL) between days 15-65 after breeding has been shown to occur in 7.9% of equine pregnancies with substantial economical, welfare and safety implications. Whilst maternal age has been recognised as an important risk factor in relation to the incidence of EPL, few other risk factors have been conclusively identified. Further, multivariable data analysis of risk factors for EPL is sparse. A prospective cohort investigation of thoroughbred broodmares in the United Kingdom was conducted over the 2013 and 2014 breeding seasons. Information relating to 28 factors including mare...
Hackett CH, Fortier LA.The field of regenerative medicine research is rapidly expanding. One area of interest to equine researchers is the possibility of isolating or generating pluripotent cells, capable of producing differentiated cell types derived from all 3 primary germ layers. Reports of equine embryonic stem-like (ES) cell isolation can be found in the literature. Other groups are working to produce equine-induced pluripotent stem (iPS) cells. This article summarizes the essential features needed to characterize a cell type as pluripotent, specific challenges in using the horse as a model organism for pluripo...
Roberto da Costa RP, Ferreira-Dias G, Mateus L, Korzekwa A, Andronowska A, Platek R, Skarzynski DJ.Nitric oxide (NO) plays an important role in angiogenesis and in the regulation of the blood flow. This study was carried out to investigate (i) the effects of endogenous estrogens and progestins and exogenous progesterone (P(4)) (5 ng/ml or 1 microg/ml) or estradiol 17beta (E(2)beta) (50 pg/ml or 1 microg/ml) on in vitro endometrial NO synthesis; (ii) the presence of different isoforms of NO synthase; (iii) and their relationship to microvascular density in the equine endometrium during the estrous cycle. NOS expression was also evaluated in the myometrium. Expression of endothelial and induc...
Amaral A, Fernandes C, Lukasik K, Szóstek-Mioduchowska A, Baclawska A, Rebordão MR, Aguiar-Silva J, Pinto-Bravo P, Skarzynski DJ, Ferreira-Dias G.We have shown that bacteria induce neutrophil extracellular traps (NETs) in mare endometrium. Besides killing pathogens, NETs may contribute for endometrosis (chronic endometrium fibrosis). Since elastase (ELA) is a NETs component that regulates fibrosis and prostaglandin (PG) output, the aim was to evaluate if inhibition of ELA would affect collagen 1 (COL1) transcription and PGs secretion by endometrium explants, in different estrous cycle phases. Follicular-FP (n = 8) and mid luteal-MLP (n = 7) phases explants were cultured for 24-48 hr with medium alone (Control), ELA (0.5 μg/ml,1 ...
Silver IA, Brown PN, Goodship AE, Lanyon LE, McCullagh KG, Perry GC, Williams IF.This project was carried out over a five year period (1977 to 1981 inclusive) at the University of Bristol following discussion between the British Veterinary Association and the Royal College of Veterinary Surgeons about the efficacy of, and ethical justification for, the practice of 'firing' (cautery). These discussions had been promoted by parliamentary questions but led to no firm conclusions because previously reported clinical investigations on specific treatments lacked adequate comparisons and controls and thus did not provide scientifically acceptable, statistically valid data. The pr...
