Treatment Of Mares Research Articles

Treatment of mares with the non-steroidal anti-inflammatory drug (NSAID) phenylbutazone transiently affects in vitro maturation of equine oocytes and blastocyst development after Intracytoplasmic Sperm Injection (ICSI)

Mares enrolled in assisted reproductive technologies (ARTs) programs are often treated with non-steroidal anti-inflammatory drugs (NSAIDs), particularly phenylbutazone (Bute), due to chronic lameness. The current study was performed to determine the effect of Bute administration on the developmental competence of in vitro-matured equine oocytes subjected to Intracytoplasmic Sperm Injection (ICSI). In a Preliminary Study, immature cumulus-oocyte complexes (COCs) recovered by post-mortem ovary harvested from two healthy mares (n = 2) treated for 10 days with Bute (4.4 mg/kg, PO, BID), and four non-treated healthy mares (n = 4), were matured in vitro and subjected to Piezo-driven ICSI. Lower oocyte in vitro maturation [Bute: 25% (3/12) vs. Control: 61% (28/46)] and blastocyst rates [Bute: 0% (0/12) vs. Control: 18% (5/28)] were observed in the Bute-treated when compared to the Control mares (P < 0.05). In the Main Experiment, a group of healthy mares (n = 9) received a daily dose of Bute (4.4 mg/kg, orally, SID) for 10 days. A control group of mares (n = 10) was treated with an equal volume of placebo. Mares in both groups were subjected to ultrasound-guided transvaginal oocyte aspiration (TVA) on days 3, 33, and 77 following the last dose of Bute (PT). Recovered COCs from both mare groups were matured in vitro and subjected to Piezo-driven ICSI. By day-3 PT, oocyte in vitro maturation rate was similar between mare groups [Bute: 65% (36/55) vs. Control: 67% (78/116); P > 0.05], while oocyte recovery [Bute: 53% (55/103) vs. Control: 70% (116/166)], cleavage [Bute: 31% (11/36) vs. Control: 62% (48/78)] and blastocyst rates [Bute: [0%] (0/36) vs. Control: 28% (22/78)] were significantly different (P < 0.05). By day 33 PT and 77 PT, differences on oocyte recovery, in vitro maturation, cleavage, and blastocyst rates were not observed between mare groups. In summary, the administration of Bute for 10 consecutive days (4.4 mg/kg, PO, SID, or BID) is associated with a decrease in the ability of immature equine oocytes to undergo in vitro-maturation (Preliminary Study) and develop to the blastocyst stage following ICSI (Preliminary Study and Main Experiment). This negative effect appeared to be transient, as 30- and 77-days post-treatment, no differences on in vitro maturation, cleavage or blastocyst rates were observed.

Effect of cloprostenol on luteolysis in jennies

An intensive farm system has progressively emerged with the rapid development of the donkey industry. One of the primary challenges impeding the development of the donkey industry and the preservation of endangered donkey species is the low reproductive efficiency of jennies (Feng Yang et.al. Equine Veterinary Journal 2021, 53: 1218-1226). In donkeys, luteolysis occurs between days 15 and 17 after ovulation (Carluccio A. et.al. Theriogenology, 2007, 68(6): 914-919). To shorten the estrus cycle, a new estrus cycle may start after luteolysis is induced by the PGF2α analog (Duccio P. et.al. Theriogenology, 2018, 121: 175-180). Treatment of mares and cattle with PGF2α analogs from the fifth day after ovulation induces luteolysis (Bergfelt DR. et.al. Theriogenology, 2006, 65(8): 1605-1619). However, information regarding luteolysis in jennies is limited. In this study, we aimed to investigate the effect of cloprostenol on luteolysis in jennies. The PGF2α analog used in the experiment was cloprostenol (0.2 mg/2 ml, Ningbo Second Hormone Factory, Zhejiang, China). To study the effects of different cloprostenol doses on the estrus cycle, jennies were treated with 0.2 mg (n=30), 0.4 mg (n=30), or 0.6 mg (n=30)cloprostenol (PGF2α), respectively. The time of luteolysis, ovulation interval, follicular size at ovulation, and ovulation rates were compared between the groups. The results showed that luteolysis rates in the jennies within 72 h of treatment were higher than 90% in the three treatment groups. The time required for luteolysis was not statistically different among the three groups. In addition, the estrus interval, ovulation interval, ovulation diameter, and ovulation rate did not differ among the three groups. To examine the timing effect of cloprostenol treatment on the estrus cycle, jennies were treated with 0.4 mg cloprostenol on the third (D 3, n=30), fifth (D 5, n=30), or seventh (D 7, n=30) day following ovulation, respectively. The results showed that the luteal phase of the D 3 treatment group was shorter than that of the D 5 and D 7 treatment groups, and in the D 5 treatment group was shorter than that of the D 7 group (P < 0.05). In can be concluded that treatment with 0.4 mg cloprostenol on the third day following ovulation shortens the length of the luteal phase and estrus cycle considerably.

Increased AMH plasma concentration and small antral follicles - Deslorelin slow release implants as a promising tool for preparation of mares for OPU?

A major factor affecting oocyte yield during ovum pick-up (OPU) procedures in mares is the number of follicles present on the ovary and the associated number of recovered oocytes (Cuervo-Arango et al. Reproduction, Fertility and Development. 2019; 31(12): 1894-1903). The interest in manipulation of ovarian follicular populations in horses is increasing because of benefits with regard to the oocyte yield and the overall outcome for assisted reproductive procedures. This study aimed to evaluate effects of slow-release implants containing deslorelin acetate on antral follicle counts (AFC), follicular subpopulations of different size ranges and plasma anti-Mullerian hormone (AMH) and gonadotrophin concentration in mares. Haflinger mares (n=12) were synchronized with two injections of a PGF2α analog. One day after the second injection, mares were randomly assigned to the slow-release implant (DES, 9.4mg deslorelin implant, n=6) or the control group (CON, deslorelin short-acting formulation, 1.25mg, n=6). Transrectal examination of the genital tract and collection of blood samples for the analysis of progesterone, AMH and gonadotrophins were performed until day 90 and on days of AFC assessment. AFC and follicle numbers according to size groups were determined on days 0, 10, 25, 50, 90, 180, 270 and 360 after implant insertion. The interval from implant insertion to the first spontaneous ovulation was prolonged in group DES (23.8±10.5 days) compared to CON(17.0±3.9 days) (p<0.05). Treatment influenced concentrations of LH and FSH over time (p<0.05) with the concentration of LH being greater in DES than in CON mares on days 30 and 55 and of FSH on day 15 after implant insertion, respectively (p<0.05). AMH concentration was greater in group DES from day 30 onwards (interaction treatment x time p<0.05). The AFC and the number of follicles with 5 to 10, 10 to 15 and 15 to 20 mm in diameter changed over time (p<0.05). A time x treatment interaction was demonstrated for follicles of 10 to 15 mm in diameter with more follicles of this size present in DES than in CON mares on day 90 (p<0.05). In group DES, concentration of AMH and the AFC (r=0.623, p<0.001) as well as concentration of AMH and the number of follicles 5 to 20 mm in diameter (r=0.442, p<0.01) were positively correlated whereas there was no such correlation in group CON. In conclusion, long-acting deslorelin implants induce changes in follicular development reflected in AMH plasma concentration. These changes are present from day 30 after implant insertion, suggesting that not only direct effects of deslorelin on gonadotrophin secretion but also the reduction of FSH suppressing factors from follicles such as inhibin may be involved. Treatment of mares with 9.4mg deslorelin slow-release implants might thus be a promising tool as preparation for OPU.

Results of ultrasound-guided transvaginal collection of oocytes (TVA-OPU) from mares to be fertilized by intracytoplasmic sperm injection (ICSI).

The aim of this study was to present the results of transvaginal ultrasound-guided collection of oocytes (TVA-OPU) from 21 mares to be fertilized in vitro by the ICSI method. One week before the planned OPU, the mares underwent a gynecological examination with particular emphasis on the functional status of the ovaries. The recommendation for the procedure was the presence of at least 12 ovarian follicles with a diameter of at least 4 mm on both ovaries. The selected mares were given PGF2α in a luteolytic dose 3 days before the planned OPU, so that the mares were in the early proestrus stage during the procedure and did not have a corpus luteum on the ovary. If PGF2α administration was believed to increase the risk of estrus on the day of the OPU procedure, the hormone was not administered. Immediately prior to OPU, the mares were premedicated with detomidine and butorphanol. During the procedure, symptoms of anxiety or pain were controlled using the bolus agents listed above, plus flunixin as needed. A mixture of hyascin butylbromide and sodium metamizole was also used in order to eliminate an excessive tension of the rectum. After each treatment, the mares were administered procaine penicillin, benzathine penicillin, and streptomycin. All mares underwent the OPU treatment without complications. During 24 OPU procedures (3 mares underwent the procedure twice), a total of 239 oocytes (an average of 10 oocytes from 1 mare) were obtained, 137 of which were qualified for the ICSI procedure (57% of the total). After fertilization, embryonic division occurred in 95 (70% of the oocytes qualified for ICSI). Ultimately, 23 embryos were grown and preserved in liquid nitrogen (which resulted in an average of 1 embryo per 1 OPU treatment in mares) and accounted for 17% of oocytes qualified for the treatment. According to the authors' best knowledge, it was the first project of this type in our country.

Topical ganciclovir treatment for mares naturally infected with equid alphaherpesvirus‐3: case report

Topical ganciclovir treatment for mares naturally infected with equid alphaherpesvirus‐3: case report

Fertility restoration of racing mare with persistent corpus luteum.

Background and Aim:Persistent corpus luteum (PCL) causes anestrus in mares. This study aimed to determine the effect of intrauterine prostaglandin F2α (PGF2α) treatment on PCL of racing mares to restore fertility.Materials and Methods:Twelve racing mares suspected with PCL were diagnosed using transrectal palpation and confirmed by serum progesterone (P4) concentration measurement. PGF2α was infused intrauterine, followed by serum collection at 24, 48, and 72 h after. Estrous symptoms were monitored, and mating was conducted on day 3 of estrus with an earlier injection of 8.4 μg gonadotropin-releasing hormone twice a day. Transrectal palpation was performed on days 21-30 to observe the corpus luteum. Pregnancy diagnosis was performed rectally on 40-45 days post-mating and confirmed using Doppler ultrasound scanning.Results:Eleven of the 12 mares had PCL. There was a dramatic reduction in the P4 concentration following PGF2α treatment of mares with PCL. All mares exhibited estrus 2.6±0.55 days post-treatment with a P4 concentration of 0.12±0.12 ng/mL. Rectal palpation and P4 concentration on 21-30 days after estrous onset showed that all mares were ovulating. The evaluation of P4 concentration on days 40-45 post-mating showed that all mares were still in the luteal phase. However, the pregnancy rate was only 54.5% based on rectal palpation and Doppler ultrasound scanning.Conclusion:Treatment of PCL in racing mares with an intrauterine infusion of PGF2α restored the estrous cycle and induced ovulation and pregnancy.

Action de la photopériode sur la reproduction des équidés

Juments et étalons présentent une phase de reproduction pendant les jours croissants ou longs, au printemps et en été. La majorité des juments n’ont pas d’ovulation en hiver. Ce rythme annuel de reproduction est synchronisé par les variations annuelles de la longueur du jour. Un éclairement artificiel de 14,5 h, débuté en hiver, avance la première ovulation annuelle des juments.&#x0D; Certaines des étapes de la transmission de l’information lumineuse ont été vérifiées chez les équidés. Le message lumineux est transformé en influx nerveux par des cellules spécialisées de la rétine. Cet influx, via le noyau supra-chiasmatique puis le ganglion cervical supérieur, agit sur la glande pinéale. Les pinéalocytes répondent à une stimulation noradrénergique en libérant la mélatonine. Cette hormone, sécrétée pendant la phase obscure, agit sur des récepteurs membranaires spécifiques. L’administration de mélatonine exogène sous forme d’implants sous-cutanés ou, dans certaines conditions, sous forme orale, supprime l’effet photostimulant d’un jour long. L’utilisation d’implants est actuellement à l’étude pour mettre au point un traitement de désaisonnement.&#x0D; La sécrétion des neurones à GnRH est ensuite régulée par des neuromédiateurs. La naloxone, antagoniste des opiacées endogènes, induit une décharge de GnRH suivie d’une libération de LH et de FSH chez la jument en inactivité. Les hormones thyroïdiennes ont probablement une action à ce niveau.&#x0D; L’alternance d’un mois de jours courts et d’un mois de jours longs qui permet, chez les petits ruminants mâles, d’abolir les variations saisonnières est, dans l’état actuel des travaux, inefficace chez l’étalon ou la jument.&#x0D; Pour avancer la date de la première ovulation annuelle, les éleveurs ne disposent actuellement que d’un traitement comportant 14,5 h d’éclairement par jour, commencé vers le solstice d’hiver et appliqué pendant 35 jours.

Letter to the Editor regarding ‘What is the best treatment for mares with post‐partum haemorrhage?’ by P. Wilkins

See the critically appraised topic by Wilkins and correspondence by Wilkins.

Response to letter from Dr Scoggin regarding ‘What is the best treatment for mares with post‐partum haemorrhage?’

See the critically appraised topic by Wilkins and correspondence by Scoggin.

Elevated blood urea nitrogen alters the transcriptome of equine embryos.

High blood urea nitrogen (BUN) in cows and ewes has a negative effect on embryo development; however, no comparable studies have been published in mares. The aims of the present study were to evaluate the effects of high BUN on blastocoele fluid, systemic progesterone and Day 14 equine embryos. When a follicle with a mean (±s.e.m.) diameter of 25±3mm was detected, mares were administered urea (0.4g kg-1) with sweet feed and molasses (n=9) or sweet feed and molasses alone (control; n=10). Blood samples were collected every other day. Mares were subjected to AI and the day ovulation was detected was designated as Day 0. Embryos were collected on Day 14 (urea-treated, n=5 embryos; control, n=7 embryos). There was an increase in systemic BUN in the urea-treated group compared with control (P<0.05), with no difference in progesterone concentrations. There were no differences between the two groups in embryo recovery or embryo size. Urea concentrations in the blastocoele fluid tended to be higher in the urea-treated mares, with a strong correlation with plasma BUN. However, there was no difference in the osmolality or pH of the blastocoele fluid between the two groups. Differentially expressed genes in Day 14 embryos from urea-treated mares analysed by RNA sequencing were involved in neurological development, urea transport, vascular remodelling and adhesion. In conclusion, oral urea treatment in mares increased BUN and induced transcriptome changes in Day 14 equine embryos of genes important in normal embryo development.

157 Effect of a slow-release gonadotrophin-releasing hormone analogue on ovarian activity and oestrous behaviour in mares

Oestrus behaviour in mares can contribute to problems in their handleability and reduced performance in equestrian sports. Therefore, methods of transient suppression of oestrous cyclicity in mares are of interest. The aim of our study was to determine whether treatment of mares with slow-release implants containing the gonadotrophin-releasing hormone (GnRH) analogue deslorelin downregulates pituitary GnRH receptors and reduces ovarian function and oestrous behaviour. Shetland mares (age=11.0±1.4 years; bodyweight=185.5±7kg) were oestrous synchronised with two injections of the prostaglandin F2α analogue luprostiol (3.725mg) at an interval of 12 days. One day after the second injection (Day 0), mares were randomly assigned to three groups: slow-release implant with 9.4mg of deslorelin (Suprelorin, Virbac; group D1; n=6), implant with 4.7mg of deslorelin (group D2; n=5), and intramuscular injection of 1.25mg of short-acting deslorelin (control, group C; n=5). Collection of blood samples for analysis of progesterone, LH, and anti-Müllerian hormone (AMH) using established and validated enzyme immunoassays (Scarlet et al. 2018 Theriogenology 117, 72-77), testing for oestrus-like behaviour with a Shetland stallion, and ultrasonography of the genital tract were performed at 2-day intervals until Day 10 after treatment and at 5-day intervals from there. On Days 10 and 45 after treatment, LH stimulation tests with the GnRH agonist buserelin (4µg IV) were performed. Data were normally distributed; differences among groups were analysed using analysis of variance and subsequent Tukey test. Values are means±s.e.m. In all mares without a corpus luteum on Day 0 (progesterone &amp;lt;1ngmL−1; one mare in group D1 and two in group C), ovulation was detected within 9 days after deslorelin treatment. These ovulations were classified as deslorelin induced, whereas ovulations after Day 10 were classified as spontaneous ovulations. The mean interval from deslorelin until the first spontaneous ovulation was 62.0±8.6, 44.2±14.1, and 22.2±3.1 days in groups D1, D2, and C (P&amp;lt;0.05), respectively. Subsequent oestrous cycles were regular. Oestrus-like behaviour until day 50 was reduced in groups D1 (2.0±0.9 days) and D2 (2.4±1.3 days) compared with group C (6.4±1.2 days; P&amp;lt;0.05). Concentration of plasma LH and AMH decreased in group D1 (P&amp;lt;0.05) but not in groups D2 and C. The GnRH stimulation test on Day 10 resulted in an increase (P&amp;lt;0.001) in plasma LH concentration in group C but not in groups D1 and D2 (treatment×time P&amp;lt;0.05). On Day 45, LH concentration increased in all mares in response to buserelin (NS among groups). Within 100 days of treatment, LH concentrations but not AMH concentrations in mares of group D1 returned to baseline. In conclusion, deslorelin slow-release implants transiently suppress ovarian function and oestrus behaviour in mares. Spontaneous ovulation is delayed in a dose-dependent manner. A decrease in AMH concentration suggests inhibitory effects of deslorelin on small antral follicles. Long-term effects on follicular dynamics and fertility in larger horses also need to be assessed.

Administration of enrofloxacin during late pregnancy failed to induce lesions in the resulting newborn foals.

A recent study demonstrated that enrofloxacin and ciprofloxacin cross the equine placenta without causing gross cartilage or tendon lesions in the 9-month fetus; however, long-term effects of in utero fluoroquinolone exposure remain unknown. To assess effects of fetal exposure to enrofloxacin on the resulting foal's cartilage and tendon strength. Healthy mares at 280days' gestation were allocated into four groups: untreated (n=5), therapeutic treatment (7.5mg/kg enrofloxacin, PO×14days, n=6), supratherapeutic treatment (15mg/kg, PO×14days, n=6) and no mare treatment with treatment of the foals post-partum (n=2). Mares were allowed to carry pregnancy to term, and foals were maintained on pasture for 5weeks. After that foals were euthanized, and their articular cartilage and extensor and flexor tendons were examined macroscopically and histologically for lesions. Tendon strength was tested by loading until failure. Administration of enrofloxacin at recommended doses in late gestation did not result in cartilaginous lesions or clinical lameness in any foal by 5weeks old. Tensile strength was greater in hind tendons than front tendons, but no difference was found between foals born from treated and control mares. Expectedly, osteochondral changes were present both in foals born from enrofloxacin-treated mares and in negative control foals with no apparent association with fluoroquinolone treatment during pregnancy. Only one time point in gestation was evaluated, and mares treated in the study were healthy at time of treatment. Additionally, it is possible that the assessments performed herein were not sensitive enough to detect subtle or functional changes in the articular cartilage. Further studies are needed to determine if enrofloxacin administration during late pregnancy potentiates osteochondral alterations in the first year of life. While this study did not assess other stages of gestation or long-term foal outcomes, short-term administration of enrofloxacin to late gestation mares did not result in macroscopic or microscopic lesions in the resulting foals by 5weeks of age.

A review of fungal endometritis in the mare

SummaryFungal endometritis is a relatively rare cause of infertility in the mare, accounting for only 1–5% of all cases of endometritis. However, it remains a challenge to the clinician due to difficulties in diagnosing and effectively treating affected mares, resulting in a high rate of recurrence and a guarded prognosis for ongoing fertility. Often occurring as an opportunistic infection, the most common causes of fungal endometritis in the mare are yeasts (Candida spp.) and moulds with septated hyphae (Aspergillus spp.). Early detection and identification of the causative agent are vital when choosing appropriate treatment as sensitivities to commonly used antifungals vary significantly. Assessing in vitro sensitivity for each isolate is accordingly recommended. Treatment of mares with fungal endometritis is multifaceted and includes; correction of any anatomical defects, uterine lavage and systemic and/or intrauterine infusion of antifungals. Concurrent bacterial infection is common so anticipation and subsequent treatment of bacterial endometritis is also often required.

Inflammatory Mediator Production in Fetal Fluids after Firocoxib Treatment in Mares with Experimentally-induced Placentitis

Preterm labor and/or abortion causes considerable economic impact on the equine industry. Unfortunately, few experimental models exist for the induction of various pregnancy-related complications, and therefore extrapolations are made from the experimental model for ascending placentits, although inferences may be minimal. Certain steroid hormones (progestogens, estrogens) and fetal proteins (alpha-fetoprotein; AFP) might improve the diagnostics for abnormal pregnancy, but the utility of these markers in the field is unknown. To assess this, thoroughbred mares (n = 702) were bled weekly beginning in December 2013 until parturition/abortion. Following parturition, fetal membranes were assessed histopathologically and classified as either ascending placentitis (n = 6), focal mucoid placentitis (n = 6), idiopathic abortion (n = 6) or no disease (n = 20). Weekly serum samples were analyzed for concentrations of progesterone, estradiol-17β, and AFP. Samples were analyzed retrospectively from the week of parturition/abortion in addition to the preceding four weeks. For both ascending and focal mucoid placentitis, a significant increase in progesterone and AFP was noted, alongside a significant decrease in estradiol-17β and the ratio of estradiol-17β to progesterone in comparison to controls. In contrast, idiopathic abortions experienced a decrease in progesterone concentrations alongside an increase in AFP, and this was only noted in the week preceding parturition/abortion. In conclusion, spontaneous placental infection in the horse altered both endocrine and feto-secretory markers in maternal circulation, while minimal changes were noted preceding noninfectious idiopathic abortion. Additionally, this is the first study to report an alteration in steroid hormones and AFP during the disease process of focal mucoid placentitis, the etiology of which includes Nocardioform placentitis.

What is the best treatment for mares with post‐partum haemorrhage?

What is the best treatment for mares with post‐partum haemorrhage?

Seasonal Assessment of Duration of Prolactin Suppression Following Cabergoline Treatment in Mares: Unstimulated Versus Sulpiride and Thyrotropin-Releasing Hormone-Stimulated Responses

Experiments 1 through 4 were performed to test the hypothesis that season affects the duration of prolactin suppression by a single injection of the dopaminergic agonist, cabergoline. In each, six mares received cabergoline intramuscularly and four received the vehicle. The protocol was repeated around the vernal equinox, summer solstice, autumnal equinox, and winter solstice. In all experiments, cabergoline suppressed (P < .01) prolactin for at least 5 days; concentrations in fall and winter were naturally low; thus, treatment effects were harder to detect. Experiments 5 and 6 tested whether basal (unstimulated) prolactin concentrations recovered from cabergoline suppression faster (earlier) than secretagogue-induced prolactin secretion. In July, five mares each were treated with either compounded cabergoline or cabergoline in oil; four others received oil. Cabergoline suppressed (P < .0001) prolactin in both treated groups for approximately 6 days. Prolactin in daily samples returned to control levels thereafter, whereas low-dose sulpiride-stimulated secretion remained suppressed by >50% at 11 days after treatment. In the last experiment, treatment with cabergoline or oil (n = 6 mares each) in October followed by thyrotropin-releasing hormone (TRH) challenges resulted in similar responses to those in experiment 5; TRH-induced prolactin responses were still suppressed (P < .05) on day 11. In conclusion, little seasonal variation in duration of prolactin suppression in response to cabergoline was detected. In general, secretagogue-induced secretion is suppressed much longer than basal secretion. This dichotomy may indicate at least two subpopulations of lactotropes regulated differentially by dopamine input.

INFLUENCE OF PRECIPITATION QUANTITIES ON THE STRÂMTORI-FIRIZA RAW WATER QUALITY INDICATORS

This paper focuses on the evolution of quality indicators (pH, turbidity, oxidizability) of raw water in the Firiza-Strâmtori barrier lake, in between April 2015 - March 2016, in correlation with atmospheric precipitation quantities. pH, turbidity and oxidizability analyses were conducted in the time span of one year, tracking the evolution of these parameters in regards to the monthly quantity of atmospheric precipitations. For a comprehensive representation, the quality indicators of raw water, at the entrance and exit of the Baia Mare treatment plant, are also followed.

Comparative efficacy of BioRelease Deslorelin® injection for induction of ovulation in oestrus mares: a field study.

To investigate the comparative efficacy of BioRelease Deslorelin® (BRD) and Ovuplant® for induction of ovulation in cyclic mares in Australia. Ovarian follicular activity of 60 mares for a total of 95 cycles was monitored by ultrasonography until they developed a follicle ≥30 mm and a uterine oedema pattern of 3. Mares were then randomly allocated to one of three treatment groups: (1) treatment with 1.25 mg BRD, (2) a single Ovuplant pellet or (3) 1 mL compound sodium lactate control. Follicular activity was monitored with ultrasonography every 12 h until ovulation was detected or for at least 5 days post treatment. The injection site on each mare was monitored for reaction for a minimum of 5 days post treatment. There was no difference in the percentage of mares ovulating within 48 h when treated with BRD (93.75%) compared with Ovuplant (87.09%). Treatment with both ovulating agents significantly decreased the time to ovulation compared with control mares (P < 0.00005). More mares had injection site reactions with Ovuplant (64.5%) treatment compared with BRD (15.6%) or control mares (0%) (P < 0.00005). Treatment of mares with 1.25 mg BRD when there is a follicle ≥30 mm and uterine oedema pattern of 3 is as effective as treatment with Ovuplant.

Treatment with human chorionic gonadotrophin before ovulation increases progestin concentration in early equine pregnancies

For prevention of early conceptus loss in the horse, treatment with progestins has become common practice. In cattle, treatment with human chorionic gonadotrophin (hCG) during the early postovulatory phase stimulates endogenous progesterone synthesis, which is an important factor for maintenance of early pregnancy via stimulation of endometrial function and conceptus development. In the present study we have therefore investigated the influence of treatment with hCG either for induction of ovulation or during the early luteal phase on plasma progestin concentrations, size of the corpus luteum and size of the conceptus in early pregnant mares. We hypothesized that hCG treatment stimulates progestin secretion and conceptus development. In Experiment 1, induction of ovulation with hCG (1500IU i.v.; n=14) significantly increased progestin concentration between days 5 and 15 after ovulation compared to untreated controls (n=28; p<0.05; e.g. day 5 hCG i.v.: 17.2±1.9, control: 13.9±0.8ng/ml). A significant interaction (p<0.05) of hCG treatment with size of the conceptus between days 30 and 40 of pregnancy was detected. In Experiment 2, treatment of mares with hCG (5000IU) on day 5 after ovulation (n=12) did neither affect progestin secretion (e.g. day 8 hCG: 15.4±1.6, control: 17.6±1.2ng/ml) nor luteal tissue area (e.g. day 8 hCG: 9.0±0.7, control: 7.6±1.4cm2) compared to untreated mares (n=9). In conclusion, treatment of mares with hCG for induction of ovulation within 48h before ovulation but not on day 5 of the luteal phase stimulates progestin secretion and may enhance conceptus development via stimulation of endometrial function during early pregnancy.

Smooth muscle actin and collagen immunohistochemical evaluation in the endometrium of mares treated with bone narrow stem cells

Stem cells have been used to treat chronic degenerative diseases in horses. Currently, therapies like mesenchymal stem cells have been used to improve acute and chronic inflammatory conditions in tendons, joints and lower airways with good results [Barry andMurphy, Int J Biochem Cell Biol. 2004;36:568-841]. Recently bone narrow stem cells (BNSC) therapy was used in the treatment of mares with chronic degenerative endometrial disease. After SC treatment improvement in endometrial activity, distribution and glandular density was detected [Carmo et al., Reprod. Dom. Anim. 2012;47(Suppl. 4):591]. Alpha-smooth muscle actin (Alpha-sm-actin) is a functional marker for fibroblast subtypes that remodels the extracellular matrix. The aim of this study was to evaluate the effect of therapy with BNSC over collagen and Alpha-sm-actin in endometrial tissue of mares with chronic degenerative disease. Eighteen endometrial biopsies were taken from nine mares aged 14-23 years, with chronic degenerative endometrial changes. Nine biopsies where obtained on day 0 (D0) before administration of autologous SC treatment. A total of 8 x 106 cells in a volume of 0.5 ml were injected in each point into 20 different points of approximately 1 cm from each other, following a horizontal line from the tip of one uterine horn to the other. Injections were performed by hysteroscopy with a needle designed for colonoscopic procedures. Sixty days later (D60) a second biopsy was obtained from each mare. Biopsies were fixed in Bouin