Mares and horses are integral components of equine studies, focusing on the reproductive and behavioral aspects of equine biology. Mares, or adult female horses, play a significant role in breeding programs and are often studied for their reproductive physiology, gestation, and maternal behaviors. Horses, as a broader category, encompass both sexes and all age groups, providing a comprehensive view of equine anatomy, physiology, and behavior. Research in this area often investigates the differences and similarities between mares and other horses in terms of hormonal cycles, reproductive health, and social interactions. This page compiles peer-reviewed studies and scholarly articles that explore the biological and behavioral characteristics of mares and horses, offering insights into their roles in equine science and management.
Higuchi T, Nanao Y, Senba H.To report the clinical findings, surgical technique, and outcome after repair of urinary bladder rupture through a urethral incision in postpartum mares. Methods: Retrospective study. Methods: Four Thoroughbred broodmares. Methods: Medical records were reviewed for clinical signs, surgical technique, medical therapy, and outcome. The bladder was everted into the vagina through a urethral incision that included a sphincterotomy. The bladder defect was repaired with absorbable suture material in a single-layer, full thickness, simple, continuous pattern. The urethral incision was closed similarl...
Morehead JP, Blanchard TL, Thompson JA, Brinsko SP.To determine features of an early fetal loss (EFL) syndrome and evaluate potential risk factors for EFL in Thoroughbred broodmares on 4 farms in central Kentucky. Methods: Retrospective study. Methods: 288 pregnant broodmares. Methods: Year-2001 breeding records for 288 Thoroughbred broodmares were examined. Early fetal loss was defined as loss of a fetus that was viable at > or = 40 days of gestation but was subsequently lost by 5 months of gestation. Results: Overall 2001 EFL rate was 25% (73/288), median gestational age at time of fetal loss was 77 days, and median date of loss was May 7...
Allen AL, Myers SL, Searcy GP, Fretz PB.The Hematologic values of 19 equine fetuses between 202 and 238 days gestation were compared with those of their dams. The red blood cell (RBC) count, hemoglobin concentration, hematocrit, and mean corpuscular hemoglobin concentration were significantly lower in fetal blood, while the mean corpuscular volume, mean corpuscular hemoglobin, and red cell distribution width were significantly higher. Mares had a significantly higher nucleated blood cell count than fetuses, and all nucleated cells were leukocytes (WBC). Most WBC in mare blood were segmented neutrophils and lymphocytes. In contrast, ...
Cebulj-Kadunc N, Bozic M, Kosec M, Cestnik V.Haematological parameters [red blood cell count (RBC), white blood cell count (WBC), packed cell volume (PCV), haemoglobin concentration, mean cell volume (MCV), mean cell haemoglobin (MCH) and mean cell haemoglobin concentration (MCHC)] in resting Lipizzan horses were determined for 143 stallions, 104 mares and 25 foals. The mean RBC and WBC values in Lipizzans were in the lower part of the normal range for warm-blooded horses. The mean PCV, MCV and MCH values were higher, but the mean haemoglobin concentration and MCHC values were lower than reported for other warm-blooded horses. In foals, ...
Ginther OJ, Lara A, Leoni M, Bergfelt DR.Four herds of pony mares, each consisting of a stallion and six mares, were used to characterize the nature of herding by the stallion and the factors that induced the herding behavior. Herding behaviors were compared among four successive treatments (six mares alone, stallion added, two new mares added, and entire herd moved to a new pasture). A new treatment was initiated every 7 days and behavior was studied for 5 consecutive days (Days 1-5) for each treatment. Observations were made every 10 min during a 2-h period for each day. The extent of herding was quantitated by the mean distances b...
Bollwei H, Weber F, Kolberg B, Stolla R.Uterine and ovarian blood flow was investigated in four mares during two consecutive estrous cycles using transrectal color Doppler sonography. The uterine and ovarian arteries of both sides were scanned to obtain waves of blood flow velocity. The pulsatility index (PI) reflected blood flow. There were significant time trends in PI values of all uterine and ovarian blood vessels during the estrous cycle (P < 0.05). PI values did not differ between the uterine arteries ipsi- and contralateral to the corpus luteum or the ovulatory follicle. PI values of the uterine arteries showed a wave shap...
Bollwein H, Mayer R, Weber F, Stolla R.Transrectal color Doppler ultrasound was used for the noninvasive investigation of luteal blood flow during the estrous cycle in six mares. Color was displayed in Power-Mode, in which the number of color pixels on the ultrasound image is related to the number of moving blood cells. Three pictures with a maximum number of color pixels of the corpus luteum (CL) during an examination period of about 20 min were selected and digitized on a laptop equipped with an external frame grabber card. The intra-class correlation coefficient for the number of color pixels was 0.90. In all estrous cycles simi...
Puppione DL, MacDonald MH.To measure apolipoproteins in cerebrospinal fluid (CSF) from healthy mares and to determine whether CSF concentrations of apolipoproteins change during pregnancy and lactation. Methods: 5 healthy pregnant mares. Methods: 2 sets of CSF samples were obtained; initial samples were obtained 10 to 30 days before parturition (mean, 18 days; median, 17 days), and second samples were obtained 19 to 26 days after parturition (mean, 23 days; median, 23 days). Cerebrospinal fluid was collected from the lumbosacral subarachnoid space of standing horses by use of routine collection techniques. Cerebrospina...
Pommer AC, Linfor JJ, Meyers SA.Preserved stallion semen often has decreased spermatozoal motility and fertility that can vary significantly between individual stallions. It is not known whether the medium used for extending equine sperm contributes to these decreases by inducing premature capacitation during storage. If spermatozoa undergo capacitation or acrosome reaction prior to insemination, this could result in a diminished capacity to penetrate the cumulus mass and fertilize the egg. We hypothesized that skim milk-based semen extenders, similar to those used in cooled storage, stabilize sperm membranes and prolong spe...
McManus CJ, Davison LA, Fitzgerald BP.In a variety of species, glucoprivation results in the suppression of the reproductive axis. Two experiments were performed to test the hypothesis that blockade of glucose metabolism via administration of the glucose inhibitor 2-deoxy-D-glucose (2DG) to mares would cause a modification in gonadotropin and prolactin secretion. Long-term ovariectomized mares (Experiment 1, n=4) or ovary-intact mares during the follicular phase of a synchronized estrous cycle (Experiment 2, n=4 per dose) were treated with 2DG. The dose of 2DG used in Experiment 1 was 100mg 2DG/kg BW, but because severe behavioral...
Bøgh IB, Bézard J, Duchamp G, Baltsen M, Gérard N, Daels P, Greve T.In the mare, rates of fertilization and development are low in oocytes matured in vitro, and a closer imitation of in vivo conditions during oocyte maturation might be beneficial. The aims of the present study were, therefore, to investigate whether (1) equine oocytes can be matured in vitro in pure equine preovulatory follicular fluid, (2) priming of the follicular fluid donor with crude equine gonadotrophins (CEG) before aspiration of preovulatory follicular fluid promotes the in vitro maturation rate, (3) the in vitro maturation rate differs between oocytes aspirated during estrus and those...
Bailey MT, Troedsson MH, Wheato JE.The hormone-producing equine granulosa cell tumor (GCT) may secrete high levels of inhibin. Measurement of inhibin concentrations may be useful in the diagnosis and conformation of mares with GCT. Inhibin may be measured using RIA, which recognizes dimeric alphabetaA-inhibin as well as the monomeric (free) inhibin alpha-subunit, or using a two-site immunoradiometric assay (IRMA) specific for alphabetaA-inhibin. The objective of this study was to examine concurrent relationships among alpha-inhibin (as measured using RIA), alphabetaA-inhibin (as measured using IRMA), and other hormones (testost...
Nambo Y, Nagaoka K, Tanaka Y, Nagamine N, Shinbo H, Nagata S, Yoshihara T, Watanabe G, Groome NP, Taya K.In female mammals, inhibin is secreted by the granulosa cells and selectively inhibits secretion of FSH. Although circulating immunoreactive (ir)-inhibin levels decrease after ovulation as a result of the disappearance of its main source, they abruptly increase at the time of ovulation in mares. To investigate the mechanisms responsible for this increase, 50 ml of equine follicular fluid (eFF) was administered into the abdominal cavity of mares during the luteal phase (eFF, n = 4). One hour after treatment, plasma levels of ir-inhibin and inhibin pro-alphaC (but not estradiol-17beta) were sign...
Spergser J, Aurich C, Aurich JE, Rosengarten R.Mycoplasma equigenitalium and M. subdolum have been implicated in genital disorders and infertility of horses. The reported cytopathic effects of M. equigenitalium observed in vitro underscore its potential pathogenic role in reproductive dysfunction in mares. This study was initiated to determine the prevalence of mycoplasmas in the genital tract of stallions in relationship to age, clinical signs, geographic location and semen quality. For this purpose the mycoplasma flora of the genital tract of 116 stallions of the Noric breed was determined by isolation and colony immunoblotting and by po...
Egito AS, Miclo L, López C, Adam A, Girardet JM, Gaillard JL.The equine alpha(s1)- and beta-caseins (CN) were purified by chromatography on DEAE-cellulose and by reversed-phase HPLC. The alpha(s1)-, beta-, and kappa-CN were characterized either by monodimensional urea-PAGE or sodium dodecylsulfate (SDS)-PAGE or by bidimensional electrophoresis. Kappa-casein was characterized after electrophoresis by glycoprotein-specific staining. To identify alpha(s1)-CN without ambiguity, internal sequences were determined after trypsin or chymosin digestion of purified alpha(s1)-CN. These sequences, that could be estimated to correspond to 62% of the full protein, pr...
Alexander GR, Gibson KT.Two mares presented with life-threatening rectal tears were successfully treated with intensive medical management. Although surgery has been regarded as mandatory for grade 3 or 4 rectal tears in the past, recent reports have indicated the value of medical management alone. The case reports presented in this article detail the use of antibiotics, flunixin meglumine, laxative diets and faecal softeners in the medical management of two mares presented with grade 3 rectal tears.
Dalin AM, Andresen O, Malmgren L.The aim of the present study was to investigate the effect of active immunization against GnRH in mature Standardbred mares (three experimental and one control mare) on antibody titres, ovarian function, hormonal levels and oestrous behaviour. The mares were individually teased with a stallion once each day. During the first part of the experiment (period I: late April until November), blood was sampled every third day during the first 3 months, thereafter once per week. In the second part of the experiment (period II: December until August), sampling was carried out every second week. Progest...
Davidson TR, Chamberlain CS, Bridges TS, Spicer LJ.Little is known regarding the hormonal regulation of granulosa cell steroidogenesis and the ovarian insulin-like growth factor (IGF) system in the mare. The objectives of this study were to determine, first, if estradiol, insulin, and/or FSH affect steroid production by equine granulosa cells (experiment 1) and, second, if the components of the IGF system are produced by equine granulosa cells in culture as well as whether estradiol, insulin, and/or FSH affects IGF and/or IGF-binding protein (IGFBP) production by equine granulosa cells (experiment 2). Granulosa cells from small (6-15 mm), medi...
Coutinho da Silva MA, Carnevale EM, Maclellan LJ, Seidel GE, Squires EL.The objective of the study was to compare embryo development rates after transfer of oocytes collected 22 or 33 h after hCG injection into recipients inseminated within the uterus or the oviduct. Oocytes were collected at approximately 22 or 33 h after hCG injections and incubated for approximately 16 or 1.5 h, respectively, before transfer. Intrauterine inseminations using 1 x 10(9) progressively motile sperm were done approximately 12 h before and 2 h after transfer. For intraoviductal inseminations (gamete intrafallopian transfer [GIFT]), semen was centrifuged through a Percoll gradient, an...
Donadeu FX, Thompson DL.Sixteen seasonally anovulatory mares were randomly allotted to two groups and injected daily with either sulpiride (1 mg/kg body weight) or vehicle from 14 January to 14 February. Sulpiride administration increased daily plasma prolactin concentrations (P < 0.05), although the prolactin response during the 6 h following sulpiride injections decreased markedly from the 1st to the 6th day of treatment (treatment by day, P < 0.0001). Plasma concentrations of LH and FSH were not affected by treatment (P > 0.1). Injection of GnRH and TRH on 15 February showed that the response of plasma prolactin t...
Allen WR, Stewart F.A tough, elastic glycoprotein capsule envelops the equine blastocyst between Days 6 and 23 after ovulation. It maintains the spherical configuration of, and provides physical support for, the embryo as it traverses the entire uterine lumen during Days 6-17, propelled by myometrial contractions that are stimulated by pulsatile release of prostaglandin F2alpha and prostaglandin E2. The capsule also accumulates constituents of the exocrine secretions of the endometrial glands ('uterine milk') as nutrients for the mobile embryo as it releases its antiluteolytic maternal recognition-of-pregnancy si...
Judy CE, Galuppo LD.To describe a technique for endoscope-assisted disruption and removal of urinary calculi using a holmium:YAG laser in sedated, standing horses. Methods: Retrospective study. Methods: Six horses with urinary calculi. Methods: A holmium:YAG laser was used to disrupt naturally occurring urinary calculi in horses (4 geldings, 1 stallion, 1 mare). Ischial urethrotomy was performed in male horses to provide a portal for the endoscope and laser fiber. Calculus fragments were removed by a combination of lavage, transendoscopic basket snare removal, forceps, and digital manipulation. Ischial urethrotom...
Sevinga M, Barkema HW, Hesselink JW.The purpose of the present study was to compare serum calcium and magnesium concentrations in mares with or without a retained placenta (RP) and to evaluate treatment of mares with RP with oxytocin versus oxytocin combined with Ca-Mg-borogluconate solution. Blood samples were obtained within 12 h of foaling from Friesian mares with and without an RP (n = 90 and 65, respectively). Serum Ca and Mg concentrations were analyzed by atomic absorption spectrophotometry. In total, we treated 112 cases of RP in 101 Friesian mares by infusion of either oxytocin dissolved in saline solution or oxytocin d...
Bruemmer JE, Brady HA, Blanchard TL.The effects of a single or double regimen of exogenous progesterone and estradiol-17beta (P/E, total dose 300 mg P/20 mg E) were investigated in 50 postparturient Quarter Horse mares. In Trial 1, at 1 and 24 h after foaling, mares were injected with progesterone (150 mg) and estradiol-17beta (10 mg) (n = 7) or 0.9% NaCl (control, n = 13). In Trial 2, within 12 h after foaling, mares were injected with progesterone (300 mg) and estradiol-17beta (20 mg) (n = 13) or 0.9% NaCl (control, n = 17). Mares were examined daily by palpation per rectum and transrectal ultrasonography to determine the day ...
Sevinga M, Hesselink JW, Barkema HW.Because the incidence of retained placenta in Friesian mares is estimated to be high, and no reports have been published on the reproductive performance of Friesian mares after retained placenta, we studied postpartum reproductive performance in Friesian brood mares with (n = 54) and without (n = 50) retained placenta. We defined a retained placenta as the failure to expel all fetal membranes within 3 h after the delivery of a foal. We subdivided the group of mares with retained placenta into mares in which the placenta had been removed manually (n = 30) and mares in which it had not (n = 24)....
Bracher V, Mathias S, Allen WR.Videoendoscopy of the reproductive tract was performed in 87 Thoroughbred mares with histories of reduced fertility. During hysteroscopy samples for cytological, microbiological and histological examinations were obtained under visual control. Common findings in these broodmares included: (a) endometrial degeneration, as assessed by an uneven distribution or atrophy of endometrial folds and/or a scarred appearance of the endometrium (49 mares, 56%); (b) endometrial cysts of various sizes and locations within the uterus with the most common location being at the base of the uterine horns (48 ma...
Hosteller DE, Sprecher DJ, Yamini B, Ames NK.Transrectal palpation of an 18-mo-old, anestrous Holstein nulligravida revealed an enlarged left ovary. Ultrasonographically, the mass resembled known equine granulosa cell tumor (GCT) images. Slowly, virilism developed. Fifty-five days after initial diagnosis, unilateral ovariectomy was performed The presurgical serum concentration of testosterone was equal to that of a mature bull. During the 3 mo period following surgery, estrus expression resumed, the serum testosterone concentration returned to baseline, and the heifer was diagnosed pregnant following AI. A low grade, malignant GCT was th...
Resende HL, Carmo MT, Ramires Neto C, Alvarenga MA.The identification of fetal sex in horses by location of the genital tubercle between 55 and 70 days of pregnancy is hampered by the large amount of allantoic fluid, extensive fetal movements and the extremely long umbilical cord; however, reliable results have been achieved by ultrasonographic evaluation of the fetal gonads at 110-150 days of pregnancy. Objective: The aim of this study was to diagnose the sex of equine fetuses using B-mode and/or colour Doppler transrectal ultrasonography in fetuses of different ages. Methods: Cross-sectional study comparing 2 methods of determining fetal sex...
Sechin A, Deschamps JC, Lucia T, Aleixo JA, Bordignon V.We evaluated the effect of PMSG on the weaning-to-first service interval, total litter size and born alive litter size in swine. Four doses of PMSG (0, 500, 750 and 1,000 IU) were administered intramuscularly after weaning to sows at 3 different farms, grouped by parities (1, 2 and 3 or higher) and 2 distinct time periods. The associations among main effects and response variables were assessed by analysis of variance. Polynomial orthogonal terms were used to adjust the estimates of weaning-to-first service interval, total litter size and born alive litter size for the interaction effect of pa...
Klein V, Müller K, Schoon HA, Reilas T, Rivera del Alamo MM, Katila T.Oestrous suppression by intrauterine devices (IUDs) is caused by prolongation of luteal function, but the biological mechanism is unknown. The aim of the study was to investigate mechanisms which could explain the action of IUDs. Thirty mares were age-matched and either inseminated (AI, n = 15) or fitted with an IUD (IUD, n = 15) and subsequently divided into four groups: AI-P, pregnant (n = 8); AI-N, non-pregnant (n = 7); IUD-P, prolonged luteal phase (n = 7); and IUD-N, normal luteal phase (n = 8). The median ages were 5.5 and 7 years in AI-P and IUD-P groups and 14 and 11 years in AI-N and ...
Maldonado PA, Montoya TI, Acevedo JF, Keller PW, Word RA.Although the positive effects of vaginal estrogens and the selective estrogen receptor modulator, ospemifene (OS), on the vaginal epithelium are well recognized, less is known regarding the effects of these therapies on the lower urinary tract or vaginal muscularis. Clinical evidence suggests that vaginally administered estrogen may improve overactive bladder-related symptoms. The objective of this study was to compare the effects of OS, vaginal conjugated equine estrogens (CEE), or both on the vaginal wall and lower urinary tract in a rat model of menopause. Contractile force of the bladder n...
Martínez-Boví R, Cuervo-Arango J.Haemorrhagic anovulatory follicle is the most common pathological anovulatory condition in the mare, but its cause remains unknown. An experimental model to induce luteinised unruptured follicles (LUF) with flunixin-meglumine (FM) has been developed. Luteinised unruptured follicles share similar morphological and hormonal characteristics with haemorrhagic anovulatory follicles. Objective: To test the effect of intrafollicular administration of prostaglandins PGE2 and PGF2α during the periovulatory period on ovulation and pregnancy in FM-treated mares. Methods: In vivo experiment in a crossove...
Jacobson CC, Sertich PL, Mc Donnell SM.To investigate effects of a 5-day oral misoprostol regimen recommended for use in horses as a gastrointestinal mucosal cytoprotectant during colic on mid-gestation pregnancies. Objective: To monitor cervical tone, ultrasonographic characteristics of the uterus, cervix and conceptus, as well as serum progesterone and oestrone sulphate concentrations, and observations of general health, behaviour and comfort of mid-gestation mares given a 5-day course of misoprostol or control treatment. Methods: Eleven light horse and pony mares with known breeding dates were administered 5 µg/kg bwt misoprost...
Hochi S, Maruyama K, Oguri N.The present study was designed to examine the suitability of ethylene glycol as a cryoprotectant for equine embryos. Blastocysts recovered nonsurgically from Day 6 donor mares were cryopreserved by conventional 2-step freezing in the presence of 10% ethylene glycol (EG), 10% glycerol (Gly), or 10% ethylene glycol + 0.1M sucrose (EG + Suc). After thawing, the EG and Gly were removed by a 6-step manner, and the EG + Suc was diluted to one fourth in the freezing straw. The postthaw blastocysts were transferred nonsurgically into the uteri of recipient mares on Days 4 to 7 after ovulation. Pregnan...
Gérard N, Monget P.The profiles of insulin-like growth factor-binding proteins (IGFBPs) in follicular fluid have been characterized in a number of mammals (rats, pigs, sheep, cattle, humans) and are good indicators of follicular status. We studied the IGFBP profiles of equine serum and ovarian follicular fluid recovered at various stages of the follicular phase. The levels of IGFBPs were related to the morphology and the steroidogenic activity of the follicles. Follicular fluids were recovered by ultrasound-guided follicular aspiration. In the first experiment, the dominant follicles of 10 mares were partly punc...
Katila T, Oijala M.Detomidine was administered throughout 10 pregnancies in eight mares. An intravenous injection of 20 micrograms/kg body weight was given weekly from Day 14 to Day 60 of gestation and thereafter every four weeks until parturition. One mare suffered torsion of the large colon and was destroyed on Day 86; the foetus was normally developed. A further mare aborted at 167 days. The remaining eight pregnancies continued to full term. One foal was delivered by caesarean section because of torticollis and, of the seven foals born spontaneously, one had bilateral upward patellar fixation at one month ol...
Iuliano MF, Squires EL, Cook VM.A 2 X 2 cross-classified experiment was conducted to investigate the effect of age of equine embryo (7 vs 8 d postovulation) and method of transfer (surgical vs nonsurgical) on pregnancy rates at 50 d of gestation. Embryos were recovered 7 or 8 d postovulation using a Foley catheter and 3 liters of modified Dulbecco's phosphate-buffered saline (PBS). Upon identification, the embryos were placed in millipore-filtered PBS containing 20% heat-inactivated steer serum and maintained at room temperature until transferred. At the time of recovery, embryos were randomly assigned to be transferred eith...
López López C, Ferreira LMM, García U, Moreno-Gonzalo J, Rodrigues MAM, Osoro K, Ferre I, Celaya R.The number of horses in northern Spanish mountains has increased in recent decades, but little is known about their grazing behaviour, performance and potential for foal meat production. This research aimed to study the diet selection, liveweight (LW) changes and parasitic status of dry and lactating mares, and foals' LW gains, grazing on heathlands with different botanical composition. The experimental design consisted of three vegetation types: dominated by heather (Ericaceae) species (H), dominated by gorse (Ulex gallii; G) and co-dominated by gorse and heath-grasses (G-G), with four replic...
Anaya G, Fernández ME, Valera M, Molina A, Azcona F, Azor P, Solé M, Moreno-Millán M, Demyda-Peyrás S.Twin foaling is associated with chimaerism in several domestic species and is recognised in horses. In this study, 21,097 purebred Spanish (Pura Raza Español) horse births from the 2015 to 2016 breeding season were investigated for chimaerism. Twin foaled and chimaeric individuals were assessed on the basis of foaling records, short-tandem repeat (STR) parentage test results and a sex-linked STR-based technique. Fourteen twin pregnancies with 23 twin foals born alive were identified (0.066% twin foaling prevalence), including five blood chimaeric cases (21.7%; overall prevalence 0.011%), sugg...
Gobato MLM, Segabinazzi LGTM, Scheeren VFC, Bandeira RS, Freitas-Dell'Aqua CP, Dell'Aqua JA, Papa FO.Artificial insemination using cooled-transported semen has marked importance in equine breeding programs around the world, and the high value of mules has generated avid interest in donkey semen biotechnology. However, donkey semen cools poorly in commercially available equine extenders. Therefore, this study aimed to develop approaches to improve the ability of donkey semen to tolerate cooling. Ejaculates of seven donkeys (n = 21) were cooled at 5°C for 48 h in three different extenders (milk-based, SM; sodium caseinate-based, SC; or egg yolk-based, EY) in the presence or absence of seminal ...
Saltiel A, Gutierrez A, de Buen-Llado N, Sosa C.After parturition, Thoroughbred mares were mated at the first post-partum oestrus (N = 24) or at a subsequent oestrus (N = 12). All mares were examined daily for: oestrous detection, palpation per rectum of the genital tract, vaginoscopic examination and cervico-endometrial cytology. Pregnancy diagnosis was carried out at Days 18, 35 and 45 after mating. An identical first service conception rate of 50% was found in both groups. The number of neutrophils followed a descending profile to only scattered cells at the first post-partum oestrus and in Group II mares remained at this very low level ...
Madej JP, Nowacki W, Boratyński J, Borkowski J, Włodarczyk-Szydłowska A, Musiał E.Vitamin D-binding protein (DBP) participates in the actin scavenger system, it is a carrier of vitamin D and its derivatives, it manifests the capacity to bind mainly monounsaturated and saturated fatty acids, it binds to the surface of several cells and enhances chemotactic activity of C5a of the complement. The present study was aimed at answering the question whether serum DBP level in mares is related to levels of this protein in colostrum and in serum of its progeny. For this purpose, sera from 77 mares, colostra from 72 mares and sera from 69 Thoroughbred foals were collected. Mother's a...
Collas C, Fleurance G, Cabaret J, Martin-Rosset W, Wimel L, Cortet J, Dumont B.Agroecology opens up new perspectives for the design of sustainable farming systems by using the stimulation of natural processes to reduce the inputs needed for production. In horse farming systems, the challenge is to maximize the proportion of forages in the diet, and to develop alternatives to synthetic chemical drugs for controlling gastrointestinal nematodes. Lactating saddle mares, with high nutritional requirements, are commonly supplemented with concentrates at pasture, although the influence of energy supplementation on voluntary intake, performance and immune response against parasi...
Spier SJ, Carlson GP, Harrold D, Bowling A, Byrns G, Bernoco D.Four Quarter Horses (1 stallion, 3 mares) with hyperkalemic periodic paralysis were mated to unaffected horses to determine the genetic basis of the disease. The affected stallion was bred to 11 unaffected mares (4 Quarter Horses, 1 Arabian, 2 Standardbreds, and 4 Thoroughbreds). The 3 affected mares were bred to an unaffected Quarter Horse stallion. Of the 15 offspring obtained from these matings, 9 were affected with hyperkalemic periodic paralysis, and 6 were unaffected, consistent with an autosomal dominant mode of inheritance. Diagnosis was established by results of oral administration of...
Zutz C, Wagener K, Yankova D, Eder S, Möstl E, Drillich M, Rychli K, Wagner M, Strauss J.Estrogenic active compounds are present in a variety of sources and may alter biological functions in vertebrates. Therefore, it is crucial to develop innovative analytical systems that allow us to screen a broad spectrum of matrices and deliver fast and reliable results. We present the adaptation and validation of a fungal biosensor for the detection of estrogen activity in cow derived samples and tested the clinical applicability for pregnancy diagnosis in 140 mares and 120 cows. As biosensor we used a previously engineered genetically modified strain of the filamentous fungus Aspergillus ni...
Fouché N, Gerber V, Bruckmaier RM, Erni-Wespi B, Zander Y, Vidondo B, Sieme H, Claes A, Kaeser R, Burger D.Anti-Müllerian Hormone (AMH) has been linked to reproductive tract abnormalities in mares and stallions. This study aimed at evaluating AMH as a biomarker for two reproductive conditions in mares. In the first part of this study, plasma AMH was evaluated as an early indicator of the onset of cyclicity in mares in the transitional period from the anovulatory phase during winter anoestrus to the cyclic phase during the breeding season. Ten mares between 8 and 17 years old were included in the experiment which lasted from mid-February until the end of April. Ovarian activity was monitored with u...
Johnson AL, Becker SE.Four studies were conducted to evaluate the effects of several physiologic and pharmacologic agents on serum prolactin concentrations in the nonpregnant mare. An increase in prolactin measured in response to administration of thyrotropin-releasing hormone (TRH; 50 micrograms, iv) was found not to vary (P = .20) in mares in estrus compared with mares in diestrus (5 to 10 d post-ovulation). Administration in the dopamine receptor blocker, metoclopramide (25 or 100 mg, im), rapidly increased serum prolactin, and the response was dependent on dose administered (total prolactin measured for 420 min...
Karrasch NM, Hubbell JA, Aarnes TK, Bednarski RM, Lerche P.This study compared cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine and spontaneously breathing 50% or maximal (> 90%) oxygen (O2) concentrations. Twelve healthy mares were randomly assigned to breathe 50% or maximal O2 concentrations. Horses were sedated with xylazine, induced to recumbency with ketamine-diazepam, and anesthesia was maintained with guaifenesin-ketamine-xylazine to effect. Heart rate, arterial blood pressures, respiratory rate, lithium dilution cardiac output (CO), inspired and expired O2 and carbon dioxide partial pr...
Wylie CE, Newton JR, Bathe AP, Payne RJ.The electronic patient records of all equine patients of Rossdales Equine Practice between January 1, 2005 and November 1, 2013 were reviewed to determine the number of cases of supporting limb laminitis (SLL) in a large equine practice and referral hospital setting in the UK and to discuss the implications for future epidemiological studies. The clinical notes were searched electronically for a combination of 'laminitis AND (contralateral OR supporting OR overload OR weight bearing)'. The prevalence of SLL within each identified denominator population and the corresponding 95% CI were calcu...
Wagner LH, Aurich J, Melchert M, Okada CTC, Gautier C, Kaps M, Claaßen S, Aurich C.High progesterone concentrations in the early luteal phase support pregnancy, whereas subphysiological progesterone concentrations delay embryonic development at least until placentation. In this study, fetal growth and development of pregnancy was investigated in pregnancies with prostaglandin F-induced low progesterone concentrations (PGF) in the early luteal phase and control pregnancies (CON) in the same mares (n = 12). Mares were inseminated and in PGF pregnancies received the prostaglandin F analogue cloprostenol (62.5 µg) on days 0-3 after ovulation to induce subphysiological proges...
Borowska A, Lewczuk D.The aim of this study was to analyze the influence of factors on the results of 100-point judging systems, linear scoring and basic measurements, as well as differences between systems for dressage and jumping warmblood mares. The research covered official data on 1547 warmblood mares. Analysis of variance and phenotypic correlations (Pearson and partial) were used. The analysis showed that sport type significantly influenced 1/3 of biometric measurements, 2/9 traits on the 100-point system and 7/37 of linear scored traits. The influence of horse type evaluation is more significant in linear s...
White JM, Colbath AC, Schott HC.Treatment with phenylbutazone (nonselective COX inhibitor) decreases the diuretic and natriuretic effects of furosemide by nearly 30% but the effects of COX-2 specific inhibitors (firocoxib) and atypical NSAIDs (dipyrone) are unknown. Objective: Furosemide-induced diuresis after pretreatment with firocoxib or dipyrone is diminished to a lesser extent than after pretreatment with phenylbutazone. Methods: Eight healthy mares. Methods: Each mare received 4 treatments in a prospective experimental crossover study using a replicated 4 × 4 Latin Square design: furosemide alone (FU), furosemide an...
Christoffersen M, Nielsen SB, Madvig CB, Agerholm JS.Equine pregnancy failure can occur throughout gestation with etiologies varying by region. In Europe, umbilical cord torsion (UCT) has been reported to account for up to 52% of abortions and stillbirths. Little is known about what causes excessive twisting of the umbilical cord (UC), and up till now, only the length of the UC has been identified as a risk factor for UCT. The aim of the present study was to determine the association of potential maternal and fetal risk factors with UCT and umbilical cord length (UCL). A retrospective cohort study was performed on aborted or prematurely delivere...
Richards T, Burron S, McCorkell TC, Trevizan L, Patterson K, Minikhiem D, Ma DWL, Pearson W, Shoveller AK.Camelina oil is derived from a low-input, high-yield crop and, in comparison to many other dietary fat sources currently used in equine diets, provides a greater amount of α-linolenic acid [ALA; (n-3)], than linoleic acid [LA; (n-6)]. However, no research exists assessing the effects of feeding camelina oil to horses in contrast to other commonly used oils. The objective of this study was to compare the effect of supplementing camelina oil to that of flaxseed and canola oil supplementation, on outcomes related to skin and coat health in horses. Thirty adult horses [23 mares, 7 geldings; 14.9 ...
Ellerbrock M, Wehrend A.Dystocia represents a life-threatening condition for mare and foal. Morbidity and mortality rates due to a difficult birth, as well as the influence on fertility of the mare were analyzed, based on a review of publications. This was aggravated by the fact that no standardized diagnostic code was used and that most publications do not clearly describe how extensively the examinations were performed beforehand. Retentio secundinarum is the most common complication caused by dystocia. Other complications are injuries to the soft birth canal and the colon. These occur more frequently after surgica...
