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.
Poirier M, Smith OE, Therrien J, Rigoglio NN, Miglino MA, Silva LA, Meirelles FV, Smith LC.Cell reprogramming by somatic cell nuclear transfer and in induced pluripotent stem cells is associated with epigenetic modifications that are often incompatible with embryonic development and differentiation. For instance, aberrant DNA methylation patterns of the differentially methylated region and biallelic expression of H19-/IGF2-imprinted gene locus have been associated with abnormal growth of fetuses and placenta in several mammalian species. However, cloned horses are born with normal sizes and with no apparent placental anomalies, suggesting that H19/IGF2 imprinting may be epigenetical...
Kumar P, Kumar R, Mehta JS, Chaudhary AK, Ravi SK, Chandra Mehta S, Ansari MM, Legha RA, Tripathi BN, Talluri TR.The present study was designed to study the adverse effects of cryopreservation and evaluation of the cryoprotective effect of reduced glutathione (GSH) and ascorbic acid (AA) supplementation on exotic jack semen in combination or alone. For this, 24 semen samples from four adult and fertile jacks were collected via artificial vagina using an estrus jenny as dummy. After semen collection, the semen was evaluated for various qualitative and quantitative parameters in fresh, cooled, and frozen-thawed semen. The semen pellet was extended with the freezing extender containing either AA (0.9 g/L),...
Shaktivesh , Malekipour F, Whitton C, Lee PVS.Standard fatigue testing of bone uses a single load and frequency applied until failure. However, in situ, the subchondral bone of Thoroughbred racehorses is subjected to a combination (or a spectrum) of loads and frequencies during training and racing. Objective: To investigate the use of a fatigue testing method for equine third metacarpal (McIII) subchondral bone under a spectrum of loading conditions which a racehorse is likely to experience during a fast workout. Methods: In vitro biomechanical experimental study. Methods: McIII subchondral bone specimens (n = 12) of racehorses were ha...
Ripley AM, Penedo MCT, Grahn RA, Martinez de Andino EV, Walbornn SR, Serafini R, Love CC, Hinrichs K.Fetal genotyping has important applications in the horse, but currently necessitates embryo recovery and biopsy. We investigated whether fetal genotyping could be performed on yolk-sac fluid recovered from pregnant mares via transvaginal aspiration. Fluid was collected before Day 30 to provide results before establishment of the endometrial cups (Day 37). Genotyping and assessment of maternal DNA contamination was performed by analyzing histograms of PCR results for 19 loci. In Exp. 1, mares underwent yolk-sac aspiration on Days 22-28 of gestation. Fluid (0.56-1.02 mL) was recovered from fiv...
Dang W, Shang S, Zhang X, Yu Y, Irwin DM, Wang Z, Zhang S.Previous studies investigating donkey parentage and genetic diversity used horse-specific multiplex systems. However, several mis-allele and null-allele issues were found with some of the horse primers when used in donkeys. In 2017, the International Society for Animal Genetics (ISAG) recommended 13 dinucleotide short tandem repeats (STRs) (AHT4, ASB23, HMS2, HMS3, HMS6, HMS7, HMS18, HTG7, HTG10, TKY297, TKY312, TKY337 and TKY343) as a core panel that should be used to identify individuals and to test for parentage in donkeys. To date, no single multiplex STR typing system containing all 13 do...
Dijkstra A, Cuervo-Arango J, Stout TAE, Claes A.Monozygotic multiple pregnancy is rare in horses, but may be more common after transfer of an in vitro produced (IVP) embryo. Objective: To determine the occurrence, incidence, characteristics and outcome of monozygotic siblings arising from in vivo and IVP equine embryos. Methods: Retrospective case series. Methods: A total of 496 fresh in vivo and 410 frozen-thawed IVP blastocysts, produced by intracytoplasmic sperm injection (ICSI) of in vitro matured oocytes from Warmblood mares, were transferred into recipient mares. The likelihoods of pregnancy and multiple pregnancy were calculated, and...
Papas M, Arroyo L, Bassols A, Catalán J, Bonilla-Correal S, Gacem S, Yeste M, Miró J.This study compared the activities of four antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPX; and glutathione reductase, GSR) in the seminal plasma of stallions and jackasses. Eighteen stallion ejaculates and 24 jack ejaculates were collected through an artificial vagina. Seminal plasma was obtained by several centrifugations at 3000×g and 4 °C for 10 min, and activities of SOD, CAT, GPX and GSR were subsequently determined. We also evaluated whether the collecting season had any influence on the activities of these four enzymes in both stallions ...
Silva ESM, Leite RO, Maciel LFS, Francia CCDA, Padovani CR, Oliveira-Filho JP, Meira C.Aiming to investigate the effects of different hormonal protocols on the endometrium morphometry of anestrous mares, 26 animals were assigned to four different treatment groups: (1) EB2.5LAP4: single dose of 2.5 mg of estradiol benzoate (EB); (2) EB5LAP4: 5 mg of EB in 2 consecutive days; (3) EB10LAP4: 10 mg of EB in three consecutive days, considering that all EB-treated groups received a single dose of 1,500 mg of long-acting progesterone (LA P4) after the single/last EB dose; and (4) LAP4: only 1,500 mg of LA P4. Results were also compared with those found in cyclic mares (control grou...
Fedorka CE, Ball BA, Scoggin KE, Loux SC, Troedsson MHT, Adams AA.Ascending placentitis is one of the leading causes of abortion in the horse. Minimal work has focused on its effect on fetal fluids or the antenatal immune response of the fetus. Placentitis was induced via transcervical inoculation of Streptococcus equi ssp Zooepidemicus, and fluids/serum/tissues were collected 4-6 days later following euthanasia. Cytokine concentrations were detected using a multiplex immunoassay within fetal fluids (amniotic and allantoic) and serum (maternal and fetal) in inoculated and control mares. In addition, tissues from fetal (spleen, liver, lung, umbilicus, amnioa...
Orlando L, Librado P.Domestication has changed the natural evolutionary trajectory of horses by favoring the reproduction of a limited number of animals showing traits of interest. Reduced breeding stocks hampered the elimination of deleterious variants by means of negative selection, ultimately inflating mutational loads. However, ancient genomics revealed that mutational loads remained steady during most of the domestication history until a sudden burst took place some 250 years ago. To identify the factors underlying this trajectory, we gather an extensive dataset consisting of 175 modern and 153 ancient genome...
Satué K, Fazio E, Ferlazzo A, Medica P.The hypothesis that a local serotonergic network might also exist in the follicle of mares remains poorly documented, with exception for humans and laboratory species. For this reason, the aim of the present study was to clarify this possibility, investigating intrafollicular serotonin concentrations of the cycling mare at ovulation time. Sixty ovaries collected from 30 clinically healthy mares of slaughterhouse meat production with clinically normal reproductive tracts after slaughtering were evaluated. Blood samples were taken prior to sacrifice. Follicles were classified in three categories...
Beeson SK, Mickelson JR, McCue ME.Total genetic map length and local recombination landscapes typically vary within and across populations. As a first step to understanding the recombination landscape in the domestic horse, we calculated population recombination rates and identified likely recombination hotspots using approximately 1.8 million SNP genotypes for 485 horses from 32 distinct breeds. The resulting breed-averaged recombination map spans 2.36 Gb and accounts for 2939.07 cM. Recombination hotspots occur once per 23.8 Mb on average and account for ∼9% of the physical map length. Regions with elevated recombination r...
Neuhauser S, Gösele P, Handler J.Cryopreservation of epididymal sperm allows final preservation of the gene reserve from valuable sires in case of unexpected injury terminating the breeding career. This case report describes the birth of a healthy foal following insemination with frozen-thawed epididymal sperm. The testes and epididymides were removed under general anaesthesia and sent cooled to the laboratory overnight. The cauda epididymidis was dissected and 17.79 × 109 sperm were harvested by a retrograde flush technique. A fertile mare was inseminated 1 year later with frozen-thawed epididymal sperm. Sperm were deposite...
May CE, Guthrie AJ, Schulman ML.We report herein the use of crude extracts obtained from samples of Taylorella equigenitalis-infected horses for the purpose of multi-locus sequence typing (MLST). Samples (n = 36) were collected from horses in South Africa from 1996 to 2017: 34 from genital swabs (stored at -20°C for 2-3 y) and 2 from cryopreserved raw semen aliquots (stored at -70°C for 18 y) prior to assay. The MLST assay showed a single sequence type (ST), designated ST4, that supported a point introduction and thus a common source for the South African outbreak of contagious equine metritis.
Grant DM, Macedo A, Toms D, Klein C.Preimplantation equine embryos synthesize and secrete fibrinogen, which is a peculiar finding as fibrinogen synthesis almost exclusively occurs in the liver. This study investigated the hypothesis that conceptus-derived fibrinogen mediates cell adhesion during fixation. On day 21 of pregnancy, five integrin subunits, including ITGA5, ITGB1, ITGAV, and ITGB1, displayed significantly higher transcript abundance than on day 16 of pregnancy. Endometrial epithelial cells adhered to fibrinogen in an integrin-dependent manner in an in vitro cell adhesion assay. Bilaminar trophoblast and allantochorio...
Vitoria A, Romero A, Fuente S, Barrachina L, Vazquez FJ.This report describes a technique for standing laparoscopic vasectomy in stallions through a prospective descriptive study. A preliminary study was carried out with two experimental intact male horses and subsequently the procedure was performed in two clinical cases. These horse owners want to keep their animals in the most possible natural way, preserving its stallion behaviour in a herd without generating offspring. The horses were sedated and restrained in stocks and laparoscopic vasectomy was performed using three portal sites in both paralumbar fossae recording surgical times. A 4-cm seg...
Pisello L, Rampacci E, Stefanetti V, Beccati F, Hyatt DR, Coletti M, Passamonti F.This study aimed to describe bacteria isolated from the reproductive tract of mares and to identify changes in antimicrobial susceptibility patterns to those antibiotics commonly used for the treatment of equine endometritis. A total of 4122 equine uterine swabs were collected from mares suffering from reproductive tract disorders in the period 2010-2017. Aerobic culture and antimicrobial susceptibility testing using agar disc diffusion were performed on each sample. Aerobic bacteria were isolated from 3171 of 4122 (76.9 per cent) samples. The most frequently isolated microorganisms were (885...
Kwong GPS, Klein C.Horses are long-day breeders and commence ovarian follicular activity during the spring. Evidence suggests that there is an endogenous circannual rhythm in mares, and it is uncertain whether hormonal manipulation during or immediately following the fall transition induces follicular development. The current study was designed to test the hypothesis that both deslorelin and naltrexone induce follicular development in late fall transitioning or anestrous mares. Five of six mares treated with deslorelin, and 4 of 6 mares treated with naltrexone, developed a pre-ovulatory-sized follicle and were i...
The proteins galectin-1 and Progesterone Induced Blocking Factor (PIBF) are present on human and murine trophoblast and are thought to influence both immunomodulation and trophoblast invasion. In equids, the invasive component of the placenta, the endometrial cups, stimulate maternal cell-mediated and humoral immune responses. It was therefore of interest to know if galectin-1 or PIBF could be immunolocalised to the invasive and/or non-invasive components of the equine placenta. Horse and mule (♀ horse X ♂ donkey) embryos and placental tissues between Days 12 and 124 of gestation were stai...
Rosanowski S, Verheyen K.The number of unwanted horses in the UK has increased in recent years. It is therefore important to identify factors that indicate whether a horse can be rehomed and how long it takes to be rehomed. Data from 1 January 2013 until 30 March 2014 were extracted from an equine rehoming charity's database. Exposure variables were examined using multivariable logistic and Cox regression. In total, 791 horses were included in the study and 410 (51.8%) were rehomed during the study period. Median time until rehomed was 39 days (IQR 24-75). Horses whose owner was prepared to transfer ownership were nea...
Petersen JL, Lewis RM, Embertson R, Valberg SJ, Holcombe SJ.Large colon volvulus (LCV) is a life-threatening form of colic that occurs when the large colon rotates 360° or more on its axis, resulting in colonic distention and ischaemia. Any horse can suffer from LCV, but the risk is greatest for periparturient Thoroughbred broodmares; the objective of this study was to estimate the heritability of LCV in these horses. The criteria for classification as an LCV case were being a Thoroughbred broodmare from one of three farms in central Kentucky and having had surgical correction for LCV. Controls were identified as Thoroughbred broodmares present on the...
Martínez-Boví R, Zagrajczuk A, Donadeu FX, Skarzynski DJ, Piotrowska-Tomala K, Cuervo-Arango J.Haemorrhagic anovulatory follicles (HAFs) are the most common pathological anovulatory condition in the mare. To enhance understanding of the physiopathology of HAFs, the aim of the present study was to determine the effects of an induced-follicular wave on LH concentrations and follicular fluid factors relevant to the ovulatory process. Mares were allocated to treatment or control groups (n = 7/group) in a crossed over design during 14 oestrous cycles with a period of one cycle occurring when there were no treatments between the times when treatments were administered. In the treatment gr...
Li CX, Chang WS, Mitsakos K, Rodger J, Holmes EC, Hudson BJ.Papillomaviruses (PVs) have been identified in a wide range of animal species and are associated with a variety of disease syndromes including classical papillomatosis, aural plaques, and genital papillomas. In horses, 13 PVs have been described to date, falling into six genera. Using total RNA sequencing (meta-transcriptomics) we identified a novel equine papillomavirus in semen taken from a thoroughbred stallion suffering a genital lesion, which was confirmed by nested RT-PCR. We designate this novel virus (EcPV9). The complete 7656 bp genome of EcPV9 exhibited similar characteristics to th...
Leemans B, Stout TAE, Soom AV, Gadella BM.Procaine directly triggers pH-dependent cytokinesis in equine oocytes and induces hypermotility in stallion spermatozoa, an important event during capacitation. However, procaine-induced hyperactivated motility is abolished when sperm is washed to remove the procaine prior to sperm-oocyte co-incubation. To understand how procaine exerts its effects, the external Ca2+ and Na+ and weak base activity dependency of procaine-induced hyperactivation in stallion spermatozoa was assessed using computer-assisted sperm analysis. Percoll-washed stallion spermatozoa exposed to Ca2+-depleted (+2 mM EGTA) p...
Serafini R, Ghosh S, Love CC, Medrano JMR, Teague SR, LaCaze KA, Varner DD.Commercially available vaginal lubricants, typically labeled as non-spermicidal, are used to lubricate equine artificial vaginas prior to semen collection. Improper type or amount of lubricant might affect stallion sperm quality, either after short-time exposure or following cooled storage of extended semen previously exposed to lubricant. The aim of this study was to evaluate stallion sperm quality following exposure to lubricant-containing extender for 1 h (T1h) or 24 h (T24h). Three ejaculates were collected from each of four stallions using a small volume of petrolatum to lubricate a...
Ishak GM, Dutra GA, Gastal GDA, Elcombe ME, Gastal MO, Park SB, Feugang JM, Gastal EL.This study aimed to gain insight on the effect of different seasons of the year on the expression pattern of growth factor and hormone receptors involved in follicle development. A novel follicle wall biopsy technique was used to collect in vivo follicle wall layers (ie, granulosa, theca interna, and theca externa) and follicular fluid samples from growing dominant follicles, simultaneously and repeatedly, using the same mares during the spring anovulatory (SAN), spring ovulatory (SOV), summer (SU), and fall ovulatory (FOV) seasons. The immunofluorescent expression patterns of epidermal growt...
Boakari YL, Ali HE, Dini P, Loux S, Fernandes CB, Scoggin K, Esteller-Vico A, Lawrence L, Ball B.High blood urea nitrogen (BUN) decreases fertility of several mammals; however, the mechanisms have not been investigated in mares. We developed an experimental model to elevate BUN, with urea and control treatments (7 mares/treatment), in a crossover design. Urea-treatment consisted of a loading dose of urea (0.03 g/kg of body weight (BW)) and urea injections over 6 hours (0.03 g/kg of BW/h). Control mares received the same volume of saline solution. Blood samples were collected to measure BUN. Uterine and vaginal pH were evaluated after the last intravenous infusion, then endometrial biopsie...
Carossino M, Dini P, Kalbfleisch TS, Loynachan AT, Canisso IF, Cook RF, Timoney PJ, Balasuriya UBR.Equine arteritis virus (EAV) has the unique ability to establish long-term persistent infection in the reproductive tract of stallions and be sexually transmitted. Previous studies showed that long-term persistent infection is associated with a specific allele of the CXCL16 gene (CXCL16S) and that persistence is maintained despite the presence of local inflammatory and humoral and mucosal antibody responses. Here, we performed transcriptomic analysis of the ampullae, the primary site of EAV persistence in long-term EAV carrier stallions, to understand the molecular signatures of viral persiste...
Aouane N, Nasri A, Bekara MAA, Metref AK, Kaidi R.The Barb horse occupies a prominent place in the history, culture, and equestrian traditions of the Maghreb (Algeria, Morocco, and Tunisia). Although many studies on the breed standard and morphometry have been published, there are no studies on its fertility and reproductive potential. Thus, this work aimed to study the fertility of Barb, Arabian Purebred, and Thoroughbred horses in Algeria. Methods: A total of 168 stallions and 1202 mares at the Chaouchaoua Stud farm in Tiaret, Algeria, were included in the study. The reproductive performance during 1592 cycles over 10 consecutive mating sea...
He HY, Liu LL, Chen B, Xiao HX, Liu WJ.Donkey milk has high nutritional and medicinal value, but there are few researches in donkey milk traits, especially on genome. The whole lactation of 89 donkeys was recorded and it was found that Xinjiang donkey had good lactation performance while great differences among individuals. In our previous study, four genes including , , and were identified as milk-associated with Chinese Kazakh house, based on Equine 670k Chip genomic analysis. And then 15 SNPs of the four key genes were conducted for genotyping in Xinjiang donkey in this study, one of Chinese indigenous breed, 14 SNPs were succ...
Lagneaux D, Huhtinen M, Koskinen E, Palmer E.Equine embryos recovered on Day 6 after ovulation were cooled to +4 degrees C, or frozen with AFP alone or together with glycerol. Twenty embryos (140-200 microm in diameter) were randomly assigned to 6 treatment groups. In the first 3 groups, the embryos were cooled from room temperature to +4 degrees C at a rate of 3 degrees C/min and warmed again at a rate of 32 degrees C/min in a programmable freezer. In the second 3 groups, the embryos were frozen using a standard protocol, stored in liquid nitrogen for 5-7 days and then thawed in a 37 degrees C waterbath. After cooling/warming or freezin...
Müller-Unterberg M, Wallmann S, Distl O.The Black Forest Draught horse (BFDH) is an endangered German coldblood breed with its origin in the area of the Black Forest in South Germany. In this retrospective study, the influence of the inbreeding coefficient on foaling rates was investigated using records from ten breeding seasons. Due to the small population size of BFDH, the level of inbreeding is increasing and may have an effect on foaling rates.The data of the present study included all coverings reported for 1024 BFDH mares in the years 2001-2009. These mares were covered by 32 BFDH stallions from the State Stud Marbach. Data fr...
Witte TS, Melkus E, Walter I, Senge B, Schwab S, Aurich C, Heuwieser W.Persistent breeding-induced endometritis is ranked as the third most common medical problem in the adult mare and leads to enormous economic loss in horse breeding. In mares suffering from persistent breeding-induced endometritis, increased amounts of intrauterine (i.u.) fluid or viscous mucus in estrus or after breeding may act as a barrier for sperm and can contribute to low fertility. Current therapies of these mares aim to eliminate i.u. fluid and mucus by uterine lavage and/or administration of ecbolic drugs. Recently, i.u. administration of N-acetylcysteine (NAC) has been shown to suppor...
Révay T, Villagómez DA, Brewer D, Chenier T, King WA.Genetic sex in mammals is determined by the sex chromosomal composition of the zygote. The X and Y chromosomes are responsible for numerous factors that must work in close concert for the proper development of a healthy sexual phenotype. The role of androgens in case of XY chromosomal constitution is crucial for normal male sex differentiation. The intracellular androgenic action is mediated by the androgen receptor (AR), and its impaired function leads to a myriad of syndromes with severe clinical consequences, most notably androgen insensitivity syndrome and prostate cancer. In this paper, w...
Neuhauser S, Bollwein H, Siuda M, Handler J.The aim of the present study was to evaluate the effect of different freezing procedures on sperm motion, viability, the acrosome status, mitochondrial membrane potential (MMP), intracellular calcium content, and DNA integrity on epididymal stallion sperm. Therefore, the sperm of 10 healthy stallions was harvested by retrograde flushing after testectomy, diluted with a semen extender containing defined milk proteins and a freezing extender containing egg yolk and glycerol and frozen according to 4 different protocols, using a programmable freezer and a floating rack performing a slow (processe...
Beythien E, Aurich C, Wulf M, Aurich J.Seasonal changes in metabolic rate have been shown in horses and we hypothesized that this leads to the birth of smaller foals early in the year. Mares and their foals were assigned to three groups by day of foaling within the year (e.g. 1 January = day 1): Group 1 (n = 10) day 40-65, group 2 (n = 8) day 67-92, group 3 (n = 9) day 94-121. Groups did not differ with regard to parity. In foals, height at withers and body weight were determined on days 1-5 and weekly until 12 weeks of age. Chest circumference, distances fetlock to carpus, carpus to elbow, poll to nose and crown-rump lengt...
Silver M, Fowden AL.The production of uterine PGFM during different dietary states has been investigated in pregnant mares in late gestation. Arterial and uterine venous plasma concentrations of PGFM rose when food was withdrawn for 12-30 h and the V-A difference widened significantly. There was an inverse correlation between the rise in PGFM and the fall in plasma glucose during a fast, and a significant decrease in the A-V plasma glucose differences across the uterus. Plasma PGFM and free fatty acid concentrations before and during food withdrawal were also correlated but no uterine A-V difference in free fatty...
Galvão A, Skarzynski DJ, Szóstek A, Silva E, Tramontano A, Mollo A, Mateus L, Ferreira-Dias G.Knowledge on the regulation of corpus luteum (CL) function in the mare is scarce. In this study, the presence of cytokines tumor necrosis factor alpha (TNF) and interferon gamma (IFNG), and their receptors (TNFRI, TNFRII and IFNRI), was investigated in equine CL throughout the luteal phase. The effects of TNF and IFNG on secretory function and viability of luteal cells were defined in vitro. Cytokine ligands and receptors were present in steroidogenic and endothelial cells. Protein expression for TNF was greater in mid-phase and regressing CL, while TNFRI was increased in regressing CL and TNF...
Gebremedhn S, Gad A, Ishak GM, Menjivar NG, Gastal MO, Feugang JM, Prochazka R, Tesfaye D, Gastal EL.Innumerable similarities in reproductive cyclicity and hormonal alterations highlight the considerable utility of the mare to study aspects of follicular dynamics and reproductive function in view of the largely constricted, human research subjects. The bi-directional communication between the growing oocyte and the surrounding somatic cells embodies the hallmark of mammalian follicular development, partially mediated by extracellular vesicles (EVs) encapsulated with microRNAs (miRNAs) and present in the follicular fluid (FF). Here, we aimed to decipher the dynamics of the miRNAs in EVs from e...
Blythe LL, Craig AM, Lassen ED, Rowe KE, Appell LH.Plasma alpha-tocopherol (vitamin E) values were monitored serially in 9 foals sired by a stallion with equine degenerative myeloencephalopathy (EDM) and in 5 age-matched control foals (sired by a clinically normal stallion) raised in the same environment for the first year of life. Clinical evaluation determined that 8 of the 9 foals sired by the stallion with EDM had neurologic deficits consistent with the disease on one or more occasions during the study period, whereas control foals had normal gait. From 6 weeks to 10 months of age, plasma alpha-tocopherol values in foals with signs of EDM ...
Bosu WT, Van Camp SC, Miller RB, Owen RR.A five year prospective study of equine ovarian problems requiring surgical correction was undertaken at the Ontario Veterinary College. Thirty mares were studied, of which 14 had granulosa cell tumors, six were with anovulatory persistent follicular "structures", five had ovarian hemotoma, two presented ovarian hypoplasia and one each of ovarian dysgerminoma, teratoma and abscessation. The clinical signs manifested by the affected animals were varied. The affected ovaries were removed via flank or midline laparotomy or through colpotomy. Their morphology was studied and representative portion...
Alpoim-Moreira J, Fernandes C, Rebordão MR, Amaral A, Pinto-Bravo P, Bliebernicht M, Skarzynski DJ, Ferreira-Dias G.Inflammation and fibroproliferative diseases may be modulated by epigenetic changes. Therefore, we suggest that epigenetic mechanisms could be involved in equine endometrosis pathogenesis. DNA methylation is one of the methods to evaluate epigenetics, through the transcription of methyltransferases (DNMT1, DNMT3A, DNMT3B). The correlation between DNMTs and collagen (COL) transcripts was assessed for the different Kenney and Doig's (Current Therapy in Theriogenology. Philadelphia: WB Saunders; 1986) endometrium categories. Endometrial biopsies were randomly collected from cyclic mares. Histolog...
Troedsson MH, Liu IK, Ing M, Pascoe J, Thurmond M.The electrical myometrial activity of three mares with a documented increased susceptibility to chronic uterine infection (CUI) and three mares considered to be resistant to CUI was investigated. Electrodes were surgically implanted in the myometrium of the mares and electrical activity was monitored by a Grass polygraph. Oestrus was determined by transrectal ultrasonography of the reproductive tract and teasing of the mares with a stallion. Findings were confirmed by blood progesterone concentrations 35 mm was detected, the uterus was infused with a genital strain of 5 x 10(6) Streptococcus ...
Perdomo-González DI, Sánchez-Guerrero MJ, Molina A, Valera M.The aim of this work was to analyze genetic parameters such as the inbreeding coefficient (F), relatedness coefficient (AR) and partial inbreeding coefficient (Fij) of the whole PRE population, and the ancestors which account for 50% of the total genetic variability of the current population, from genealogical information. The average F of the whole PRE population (328,706 animals) has decreased from 8.45% to 7.51% in the least 20 years. The Fij was estimated for the whole PRE population, resulting in a database of 58,772,533 records containing one record for each Fij that each animal receives...
El-Sheikh Ali H, Legacki EL, Loux SC, Esteller-Vico A, Dini P, Scoggin KE, Conley AJ, Stanley SD, Ball BA.The current study aimed to elucidate the mechanisms underlying myometrial activation during equine placentitis related to progestogens and the progesterone receptor signaling pathways. Placentitis was induced via intracervical inoculation with Streptococcus equi ssp zooepidemicus in mares at approximately 290 days of gestation (placentitis group; n = 6) with uninoculated gestationally matched mares as controls (n = 4). Mares in the placentitis and control groups were euthanized, and myometrial samples were collected from two regions: region 1-parallel to active placentitis lesion with plac...
Elsohaby I, Riley CB, McClure JT.Neonatal foals with failure of transfer of passive immunity (FTPI) are at higher risk of morbidity and mortality. Successful treatment of FTPI is time-dependent, thus rapid and accurate measurement of serum IgG concentration is important for the management and care of neonatal foals. Objective: To validate the use of digital and optical refractometers for assessing FTPI in neonatal foals and compare the diagnostic performance and level of agreement of the two refractometers to the reference standard radial immunodiffusion (RID) assay. Methods: A retrospective validation study. Methods: Serum s...
Pereira GR, Lorenzo PL, Carneiro GF, Ball BA, Gonçalves PB, Pegoraro LM, Bilodeau-Goeseels S, Kastelic JP, Casey PJ, Liu IK.The objective of this study was to test the hypothesis that equine growth hormone (eGH), in combination with insulin growth factor-I (IGF-I), influences positively in vitro nuclear and cytoplasmic maturation of equine oocytes. Cumulus-oocyte complexes were recovered from follicles that were < 25 mm in diameter, characterized by morphology and were allocated randomly as follow: (a) control (no additives); (b) 400 ng/ml eGH; (c) 200 ng/ml IGF-I; (d) eGH + IGF-I; and (e) eGH + IGF-I + 400 ng/ml anti-IGF-I antibody. Oocytes were matured for 30 h at 38.5°C in air with 5% CO2 and then stained wi...
Calvete JJ, Mann K, Schäfer W, Sanz L, Reinert M, Nessau S, Raida M, Töpfer-Petersen E.We report the complete amino acid sequence of HSP-1, a major protein isolated from stallion seminal plasma or acid extracts of ejaculated spermatozoa. The protein consists of 121 amino acids organized in two types of homologous repeats arranged in the pattern AA'BB'. Each of the 13-15-residue A-type repeats contains two O-linked oligosaccharide chains. The B-type repeats span 44-47 amino acids each, are not glycosylated, and have the consensus pattern of the gelatin-binding fibronectin type-II module. This domain also occurs in the major bovine seminal plasma heparin-binding proteins PDC-109 (...
Szóstek AZ, Adamowski M, Galvão AM, Ferreira-Dias GM, Skarzynski DJ.Tumor necrosis factor-α (TNF) is a cytokine that plays important roles in functions of the endometrium. The aims of this study were to determine whether (i) ovarian steroids modulate TNF production by endometrial cells (Experiment 1); (ii) TNF effects on prostaglandin (PG) production in cultured equine endometrial cells and tissue (Experiment 2). Epithelial and stromal cells were isolated from equine endometrium (Days 2-5 of the estrous cycle; n=20) and treated after passage 1. In Experiment 1, epithelial and stromal cells were exposed to progesterone (P4; 10(-7)M), 17-β estradiol (E2; 10(-9...
Rivera Del Alamo MM, Reilas T, Kindahl H, Katila T.Intrauterine glass balls are used to prevent oestrous signs in sports mares, but the mechanism of action is unknown. It has been suggested that the glass ball can mimic an embryo or act via an induced chronic uterine inflammation and absent or continuous low-grade prostaglandin (PG) release. The purpose of this study was to induce prolonged luteal function in mares using a small intrauterine device (IUD) and to study the mechanisms behind prolonged IUD-induced luteal function. A uterine swab and a biopsy specimen were obtained in early oestrus. A water-filled plastic ball, diameter 20mm and we...
Jung HJ, Song H, Yoon MJ.Deleted in azoospermia-like (DAZL) is used as a germ cell marker in several species, including mice, rats, pigs, rhesus monkeys, bulls, and humans. Our objectives with this study were to investigate DAZL expression in stallion germ cells by using immunofluorescence, immunocytochemistry, and western blotting, and to determine the effects of reproductive stage and breeding season on the DAZL-positive cell population in seminiferous tubule cross sections. Testes were obtained during routine castration procedures at a large animal clinic and routine field service castration. The reproductive stage...
Schlafer DH.During the 1960s and 1970s, the clinical value of equine endometrial histopathology was firmly established after it was shown that fertility outcome was correlated with the presence and severity of specific microscopic lesions. The objective of this paper is to summarize reports from the veterinary literature published after the mid 1980s that describe new diagnostic methods of assessing equine uterine health using material collected by endometrial biopsy.
Foote AK, Ricketts SW, Whitwell KE.Significant progress has been made in understanding and monitoring the causes of equine abortion over past decades. However, not all in utero pathology results in abortion. It has long been recognised that some in utero pathology, such as twinning or chronic placentitis, can result in the birth of live but growth-retarded foals and there is historical evidence that birth weight may influence future athletic performance. Clinical experience (e.g. from twins) and experimental studies (pony-Thoroughbred embryo transfer) have highlighted the importance of reduced functional placental area in limit...
Scarlet D, Wulf M, Kuhl J, Köhne M, Ille N, Conley AJ, Aurich C.Anti-Müllerian hormone (AMH) has gained increasing interest as a biomarker for assessment of gonadal activity. The ability to predict the ovarian follicular reserve of prepubertal female horses (fillies) or to identify stallions with testicular pathologies already during their prepubertal life has not been analyzed so far. Both would help to select fertile horses and reduce costs associated with keeping animals. The objectives of the present study were to (1) assess AMH, LH, FSH, progesterone (females) and testosterone (males) dynamics in prepubertal horses from birth onwards and (2) determin...
Silva LA, Klein C, Ealy AD, Sharp DC.This work examined how the conceptus modulates endometrial tissue remodeling and vascular development prior to implantation in mares. A macroscopic uterine examination was completed at day 21 of pregnancy. In situ morphology revealed that the endometrium involved in encroachment is restricted to the dorsal endometrium immediately overlying the yolk sac. The amount of stromal area occupied by blood vessels and the number of endometrial glands were increased during early pregnancy. Endometrial histomorphometry as well as the endometrial mRNA abundance and immunolocalization of VEGF, VEGFR1, VEGF...
Galvao AM, Ramilo DW, Skarzynski DJ, Lukasik K, Tramontano A, Mollo A, Mateus LM, Ferreira-Dias GM.Proapoptotic factor Fas ligand (FASL) and its cell surface receptor FAS are tumor necrosis factor superfamily members that trigger apoptosis in different cell types. However, their influence on luteal steroidogenesis is not clearly understood. The aim of the present work was to determine (i) the presence of the cytokine FASL and its receptor FAS in the mare's corpus luteum (CL) throughout the luteal phase, as well as (ii) the influence of FASL alone, or together with the cytokines tumor necrosis factor alpha (TNF) and interferon gamma (IFNG), on equine luteal cell production of luteotrophic an...
Love CC, Kenney RM.A variety of testicular insults can induce changes in the structure of spermatozoal chromatin, resulting in spermatozoal DNA that is more susceptible to acid-induced denaturation. The degree of change in the DNA can be measured using the sperm chromatin structure assay (SCSA). The SCSA measures the relative amounts of single- and double-stranded DNA after staining with the metachromatic dye, acridine orange. Here we used a stallion model (n = 4) to study the effects of scrotal heat stress on spermatozoal DNA. This model was created by insulating stallion testes for 48 h and collecting sperm da...
Thomson P, Pareja J, Núñez A, Santibáñez R, Castro R.Culture-independent techniques have made it possible to expand the knowledge about the composition of bacterial communities present in the healthy uterus and their role in health and disease, mainly in humans. However, in animals like mares, there is a dearth of information regarding this area. To narrow this knowledge gap, the objective of this study was to identify and characterize the composition and function of the uterine microbiome of a group of Chilean purebred mares (CPM), an equine breed with the oldest genealogical record in South America and an economical important reproductive indu...
Leal GR, Monteiro CAS, Carvalheira LR, Souza-Fabjan JMG.Simulated Physiological Oocyte Maturation (SPOM) mimics in vitro the physiological events of oocyte maturation. The system uses cAMP modulators in two steps (pre IVM and IVM) and has presented promising results that are arousing the curiosity of IVF programs in different animal species, generating several papers, adaptations, and controversies worldwide. This study systematically analyses the data in the literature on the use of SPOM and compares the outcomes to the original paper (Albuz et al. Hum. Rep., 25: 2999-3011 2010), classifying them into success or failure. The PubMed, Scopus, and ...
