Pathologic findings in the oviducts of mares

Oviducts from 325 mares were evaluated macroscopically, and oviducts from 124 mares were evaluated microscopically. Two hundred and eighty-five (87.69%) of the mares had at least 1 macroscopic lesion and 116 (93.54%) had at least 1 microscopic lesion. The most frequently seen macroscopic lesions were adhesions, paraovarian cysts, and thick fibrous bands. Microscopically, intraepithelial cysts, slight, focal lymphocytic infiltration in the infundibular-ampullary region, and proteinoid material in the oviductal lumen were the most common findings. In general, the proximal segments of the oviduct were more affected than were the distal segments. Forty-nine (90.74%) of the 54 pairs of oviducts collected from pregnant mares had at least 1 macroscopic or microscopic lesion.     

Laparoscopic application of PGE2 to re-establish oviducal patency and fertility in infertile mares: a preliminary study

REASONS FOR PERFORMING STUDY: Mares are occasionally encountered that consistently fail to conceive when inseminated, naturally or artificially, with fertile stallion semen in the absence of any identifiable pathology of either the structure or function of their reproductive tract. HYPOTHESIS: Temporary blockage of the oviducts by accumulations of naturally occurring oviducal masses may be preventing oviducal transport of the embryo to the uterus. METHODS: Mares, with known reproductive histories, that had exhibited inexplicable failure of conception were treated by laparoscopically guided administration of PGE2-laced triacetin gel directly onto the surface of their oviducts. RESULTS: Fifteen mares age 10-21 years that had exhibited inexplicable failure of conception during 1-4 years were treated, of which 14 (93%) conceived within the same or subsequent breeding season. CONCLUSIONS: The high success rate of this treatment supports the tentative diagnosis of oviducal obstruction in these mares and indicates that blockage of the mare's oviducts may occur in the form of a moveable accumulation of debris rather than from permanent fibrous adhesions resulting from salpingitis. POTENTIAL RELEVANCE: This laparoscopic application of PGE2 to the oviducts constitutes a sound and practical method of restoring fertility in mares suffering oviducal obstruction and further studies involving the procedure are warranted.     

Heterogenous and xenogenous fertilization of in vivo matured equine oocytes

Forty-five in vivo matured equine oocytes were recovered from 63 follicular aspiration attempts (71.4%). HCG did not improve recovery rate (65% — 24/37 for treated vs 81% — 21/26 for nontreated mares). Fifteen oocytes were transferred into the oviduct of inseminated recipient mares (heterogenous fertilization) and 15 oocytes plus equine spermatozoa were transferred into rabbit oviducts (xenogenous fertilization). Ten oocytes (3 fertilized) were recovered from recipient mare oviducts following removal and flushing two days after transfer. Eight oocytes (nonfertilized) were recovered from rabbit oviducts. Oviductal transfer into separate recipient mares of three embryos produced from heterogenous fertilization resulted in two pregnancies. One mare produced a normal live foal and the other mare aborted at 20 days of gestation. Results from these studies suggest that: 1) a reliable method for collection of in vivo matured oocytes has been established, and 2) heterogenous fertilization is a technique that with refinement should be immediately applicable to obtain foals from valuable infertile mares that fail to get pregnant or produce embryos by standard methods.     

Electrocoagulative removal of endometrial cysts in the mare

Six mares had endometrial cysts removed by endoscopic electrocoagulative surgery. These mares exhibited poor reproductive histories and endometrial cysts were the only detectable abnormalities. In each case, at least two cysts greater than 2.5cm were present. One mare subsequently produced a live foal; two are presently in foal; one conceived but absorbed; one formed more cysts after surgery; and one has not yet been bred. Histologically, the walls of the cysts contained entire lamina propria, relatively normal endometrial glands, and small cystic spaces.     

Videoendoscopic evaluation of the mare's uterus: II. Findings in subfertile mares.

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 mares, 55%); (c) fluid accumulation in the uterine lumen (28 mares, 32%). A few mares had transluminal adhesions (7 mares, 8%) and in 2 mares the adhesions appeared to obstruct one uterine horn completely. A solitary discrete lump was detected in the wall of the uterine body in one mare and the suspicion of it being a leiomyoma was confirmed histologically with the aid of a visually directed biopsy sample. Free intraluminal structures were present in the uterine lumen in 3 mares, including one inspissated blood clot and two suspected remnants of resorbing pregnancies. Flexible biopsy forceps and scissors passed through the working channel of the endoscope were used to sever small thin adhesions, but this method proved inadequate for multiple adhesions or cysts. Solitary endometrial cysts were removed by means of conventional rigid biopsy forceps passed alongside the endoscope, although bleeding from the operation site usually limited this type of intervention.     

Accumulation of Fluid in the Infundibulum During the Estrous Cycle in Mares

The funnel-shaped cranial portion (infundibulum) of the oviduct is contiguous with the ovulation fossa in mares. An accumulation of fluid in the infundibular area was discovered by transrectal ultrasonic imaging and was studied daily in both oviducts of 12 mares from day –10 to day 10 (day 0 = ovulation), and from day –6 to day 6 during 35 estrous cycles of young, intermediate, and old mares (n = 8 mares/group). The infundibulum was identified by processes (fimbriae) and folds in the pocket of fluid. The amount of fluid accumulation was scored from 0 to 3 (nil to maximum). Frequency of detection of fluid in the infundibular area increased between day –10 (46% of oviducts) and day –3 (88%), and decreased between day –3 and day 7 (8%; P < .002). The day-to-day profile for changes in the score for amount of fluid was significant (P < .0001) and similar to the profile for frequency of detection of the infundibulum. The profiles for the two infundibular end points and scores for endometrial echotexture (an indicator of edema) were similar to the reported profile for systemic estradiol concentrations. The frequency of infundibulum detection was greater (P < .0009) for the side ipsilateral to the preovulatory follicle and ovulation (51%) than for the opposite side (36%). No difference among ages was found for either oviductal end point. Results indicated that changes in the amount of fluid accumulation in the infundibular area and endometrial edema were estrous cycle dependent and similar to previously reported changes in systemic concentrations of estradiol.     

The electrosurgical treatment of endometrial cysts in the mare

A minimally invasive technique for the removal of endometrial cysts is described. Intraluminal cysts hinder the migration of the embryo through the uterus in early pregnancy and in a later stage hinder placenta development and hence diminish the chance of successful pregnancy. Cysts can also give rise to false-positive results in early pregnancy tests. Endometrial cysts located in the lumen can be removed surgically from the standing mare. After placement of the endoscope, a wire is placed, via the biopsy channel, around the base of cyst, which is then cut through by cauterization. The cyst is removed with the help of forceps. Five barren mares with multiple cysts were treated in this way during the anoestrous period for October to February. Three of these mares became pregnant during the next oestrus period.     

Histological Characteristics of the Equine Oviductal Mucosa at Different Reproductive Stages

The objective of this work was to study cellular changes in the epithelium of the mare’s oviduct. Oviductal samples were taken from mares at different reproductive stages for optical microscopy and Hoechst 33258 staining. Glandular-like structures were observed in 100% of the oviducts. These structures were of the tubular type and were formed by ciliated and nonciliated epithelial cells arranged in a way similar to the epithelial surface. The amount of structures decreased progressively from the ampulla to the isthmus, but did not change through the different reproductive stages. Histological changes in the epithelium of the oviduct were observed associated with the reproductive stages. In the ampulla, the amount of ciliated cells decreased in the anovulatory phase compared with other reproductive stages. Cords of connective tissue lined by epithelium (trabeculae) and dividing completely the lumen of the oviduct were found in 50% of the oviducts. Epithelial cells projected toward the lumen as large vesicles of cytoplasm, sometimes containing a nucleus. The amount of cells presenting nuclear protrusion varied throughout the oviduct, with highest incidence in the ampulla, decreasing progressively toward the isthmus (P < .05). In addition, nuclear protrusions were higher in number during the anovulatory and luteal phases than in the other reproductive stages (P < .05). These nuclear protruding cells appeared to be extruding from the epithelium and showed no signs of apoptosis based on the histological and fluorescent stains used. The existence of these gland-like structures in the oviductal mucosa should be considered when studying the oviductal physiology in mares.     

Factors Influencing the Frequency of Pregnancy Loss among Thoroughbred Mares in Hidaka,Japan

Pregnancy loss in mares is thought to be a main problem associated with reproductive efficiency. To clarify the situation of pregnancy loss in Thoroughbred mares in Japan, the occurrence of pregnancy loss before and after 35 days of gestation was investigated with 1,476 Thoroughbred mares in Hidaka, Japan, from 2007 to 2009. Pregnancy loss on days 17-35 was determined by ultrasound examination between 17 and 35 days after the last mating. Follow-up surveys were conducted between 35 days and foaling to determine pregnancy loss on day 35 until foaling in 843 of these mares. Using multiple logistic regression analysis, we assessed the influence of mare age, reproductive status, twin pregnancy reduction, body condition score (BCS), estrus type in foaling mares (foal heat or not), progesterone therapy, and endometrial cysts on pregnancy loss rates on days 17-35 and on day 35 until foaling in this population of mares. The pregnancy loss rates on days 17-35 and on day 35 until foaling were 5.8% and 8.7%, respectively. The overall pregnancy loss rate (day 17 until foaling, including parturient losses) was 14.7%. Risk factors for pregnancy loss included decrease in BCS between 17 and 35 days, <5 BCS at day 35, mating during foal heat, and endometrial cysts. In all, 14.7% of pregnancies were lost between day 17 and birth, contributing significantly to reduced reproductive efficiency in Thoroughbred mares in Japan. These observations indicate that mares should be maintained at high BCS and should be prevented from mating in foal heat to decrease the pregnancy loss rates.     

Effects of Neodymium:Yttnum Aluminum Garnet Laser Irradiation on Endometrium and on Endometrial Cysts in Six Mares

Effects of neodymium:yttrium aluminum garnet (Nd:YAG) laser irradiation on equine endometrium were evaluated In vitro and in six mares with endometrial cysts. The Nd:YAG laser was applied to six endometrial sites, in each of five uterine specimens, with power densities of 5659 to 33,954 J/cm². Depth of tissue ablation was measured and graded on histologic sections of the tissue lesions. Power density had a significant effect on the depth of tissue ablation (p < .001). Grade 3 lesions (full-thickness ablation of the endometrium) were created with energy densities of 16,977 to 33,954 J/cm². Six mares had endometrial cysts treated by photoablation. Two of the four mares that were reproductively sound but barren, despite appropriate breeding, produced foals after treatment. One mare remained reproductively unsound after treatment, and another mare that was treated postpartum was bred successfully.     

A PATHOLOGICAL AND BACTERIOLOGICAL ABATTOIR SURVEY OF THE REPRODUCTIVE TRACTS OF MERINO EWES IN WESTERN AUSTRALIA

Macroscopic examination of 487 ewe reproductive tracts from 18 different sources was made at Perth abattoirs. Of these, 194 were examined microscopically and 217 bacteriologically. Observations were made during March to May, when ewes were not grazing oestrogenic pasture. Significant lesions in ovaries or oviducts were rare. Macroscopic cysts were found in the uterus or cervix of 159 ewes (32.7%). Microscopic lesions, including uterine or cervical cysts and squamous metaplasia or goblet cell hyperplasia of the epithelium, were observed in 76% of ewes studied. Bacteria were isolated from 59 ewes, the most common genera being Corynebacterium, Escherichia, Streptococcus and Bacillus. Escherichia coli and streptococci appeared to be the most commonly associated with endometritis. Presence of bacteria was closely associated with endometritis and with cysts in the cervix. Endometritis was observed microscopically in 48 ewes (24%) and was significantly associated with the presence of cysts in the uterus or cervix. These results suggest that there is a high incidence of clover disease lesions in West Australian ewes, and that under commercial conditions clover disease may cause functional damage to the cervix, allowing passage of bacteria and resulting in endometritis.     

Pregnancy diagnosis in thoroughbred mares using radioimmunoassay (RIA), enzyme immunoassay (kit) and ultrasound echography (scanning)

On the basis of progesterone determination on plasma or blood after RIA and the kit method respectively and consecutive scanning performed on a total number of 31 mares the following features were demonstrated: The overall material shows that in 20 mares (64.5%) embryonic vesicles were demonstrated. Of these mares 16 have conceived after service in the 1st estrous cycle and 3 mares in the 2nd estrous cycle. 18 mares were scanned in the time interval 13th-26th day after the latest service, while 2 mares were scanned on day 46 and 41 respectively. A total of 14 scanning positive mares were examined for progesterone by the RIA as well as by the kit method. For these mares (100%) agreement was found between the progesterone analyses as well as with the scanning results. For 19 mares (100%) there was agreement between kit and scanning results. 15 RIA progesterone determinations are in agreement with the scanning results. Progesterone values after the RIA method performed on 15 scanning positive mares were in average 8.40 +/- 2.79 ng/ml plasma. A total of 9 out of 10 scanning negative mares have been examined by the RIA as well as by the kit method. In 6 of these mares with 7 estrous cycles agreement has been found between progesterone analyses and the scanning results (77.8%). In 2 mares (no. 2 and 4) discrepancy has been found in the 2nd estrous cycle between RIA, kit and scanning results. For 1 mare (no. 7) discrepancy has been found in the 1st and 3rd estrous cycle between RIA and scanning.(ABSTRACT TRUNCATED AT 250 WORDS)     

In Vitro Production of Equine Embryos

The development of methods to produce embryos in vitro in the horse has been delayed compared with other domestic species. Oocytes can be collected from excised ovaries or from the small or preovulatory follicles of live mares. Intracytoplasmic sperm injection is the only reliable method to fertilize equine oocytes in vitro. Intracytoplasmic sperm injection-produced embryos can be transferred into the oviducts of recipient mares or cultured to the morula or blastocyst stage of development for nonsurgical embryo transfers into recipients' uteri. Embryos cultured in vitro have some morphological differences compared with embryos collected from the mares' uteri. Most notably, the embryonic capsule does not form in culture, and the zona pellucida fails to expand completely. However, embryo produced in vitro can result in viable pregnancies and healthy offspring.     

Clients' Perspectives on the Effects of Laparoscopic Ovariectomy on Equine Behavior and Medical Problems

Because laparoscopic surgery eliminates the side effects of general anesthesia, the success and therefore the use of laparoscopic surgery continues to broaden. Laparoscopic ovariectomy, once only used to treat medical problems such as granulosa cell tumors, is now being expanded to treat behavioral problems in mares. Thirty-five mares with behavioral or medical problems were treated with ovariectomies, and their owners were later contacted and questioned concerning the effect of ovariectomy on their mares.Behavioral improvement was seen in 83% (19/23) of mares treated for behavior-related problems. Aggression problems improved in 86% (12/14) of cases, general disagreeable demeanor improved in 81% (17/21), and excitability improved in 75% (12/16) of cases in which these behaviors were previously observed. Kicking and biting improved in 73% (8/11), problems in training improved in 72% (13/18), and frequent urination and problems with other horses improved in 64% (7/11 and 9/14, respectively) of cases.Owners with nonovariectomized mares also were contacted to compare the normal progression of mare behavior over time with the behavioral change in ovariectomized mares. A statistically significant change in behavior of ovariectomized mares over nonovariectomized mares was seen in the categories of decreased aggression (P < .01), decreased training problems (P < .025), decreased frequency of problem behaviors (P < .001), and improved overall behavior (P < .01).In cases in which medical problems such as granulosa cell tumors, ovarian cysts, and cycle-related colic were treated with ovariectomy, all of the clients were very satisfied with the treatment, whereas clients attempting to treat cycle-related laminitis were dissatisfied.     

Secretion of Salmonella-specific antibodies in the oviducts of hens experimentally infected with Salmonella enteritidis

The production and secretion of Salmonella enteritidis whole cell antigen-specific antibodies in the oviducts and in the serum of laying hens experimentally infected with Salmonella enteritidis, was analyzed by ELISA. The dynamics of the antibody levels in the oviducts were identical to that in the serum. Subclasses of antibodies (IgA, IgG, and IgM) in the infected hens were found to increase significantly (p < 0.01) compared to those in the control uninfected hens throughout the experiment. IgG and IgM levels in both oviducts and in sera reached to a peak by 14 days post-inoculation, and remained elevated throughout. The secretion of IgA seemed to be transient since the IgA levels increased to a peak 7 days after both primary and secondary inoculations, and declined rapidly. The elevated levels of antibodies were followed by partial clearance of Salmonella organisms from the oviducts. The present results indicate a significant local immune reaction against the Salmonella infection and suggest an association of the local antibodies with the clearance of Salmonella from the oviducts at least partially.     

马eCG/LHβ亚基基因多态性研究

马绒毛膜促性腺激素(equine chorionic gonadotropin,eCG)是由妊娠期母马胎儿尿膜—绒毛膜细胞分泌的一种由α、β两个亚基组成的异源二聚体糖蛋白,具有FSH、LH的双重活性。采用PCR-SSCP和测序方法对28匹蒙古马和25匹纯血马的eCG/LHβ亚基基因的多态性进行研究,结果发现,在蒙古马eCG/LHβ亚基基因5′调控区存在一突变位点:G-415A分为AA、BB、AB 3种基因型,AA、BB、AB基因型频率分别为0.89、0.07、0.04;纯血马此基因中未检测到多态性。     

Live foals produced from sperm-injected oocytes derived from pregnant mares

Recently, in vitro fertilization (IVF) in the horse has met with less than anticipated results. Various problems associated with equine IVF include: (1) the inability to collect large numbers of good quality oocytes, (2) the alteration of the zona pellucida associated with in vitro maturation of equine oocytes, and (3) the improper preparation of equine sperm cells for IVF of these oocytes. Therefore, this study was conducted to achieve fertilization via sperm injection of equine oocytes and to produce live offspring from this IVF procedure. Oocytes were collected by transvaginal ultrasound-guided oocyte retrieval procedures from early pregnant mares of mixed breeds (day 14 to day 70 of pregnancy) and were matured in vitro and subjected to intracytoplasmic sperm injection (ICSI). Injected oocytes were then cultured for 48 hours in either TCM-199 or P-1 medium (glucose and phosphate-free medium) supplemented with 15% fetal bovine serum. Cleavage rates for embryos cultured in the two culture media were different (47% vs. 63% in TCM-199 and P-1, respectively). Also, four Grade 1 embryos were surgically transferred into the oviducts of four recipient mares (one embryo/mare) at 48 hours post-ICSI, with three pregnancies (75%) developing as ultrasonically demonstrated by the presence of an embryonic vesicle in the uterine body by day 16 post-ICSI. On June 23rd one live filly was born after 328 days of gestation and subsequently, a second healthy filly was born after 319 days of gestation. To our knowledge, this is the first report of live foals resulting from in vitro fertilization (via ICSI) of in vitro matured oocytes recovered from pregnant mares using an efficient, repeatable transvaginal ultrasound-guided procedure.     

Progesterone therapy in mares with abnormal oestrous cycles

In two studies in Holland and France a total of 41 mares found either to be in anoestrus or showing continuous oestrous behaviour during the early part of the covering season were treated with a progesterone releasing intravaginal device. Of the 32 mares in the first study, 24 ovulated after treatment and 11 became pregnant to a covering at the induced oestrus. In the second study all but one of the nine mares showed oestrus, seven ovulated and six became pregnant at the post treatment oestrus. By the end of the covering season 15 of the 21 mares treated for anoestrus and seven of the 11 mares treated for persistent oestrus were found to be in foal.     

The effect of dietary protein on reproduction in the mare. VII. Embryonic development, early embryonic death, foetal losses and their relationship with serum progestagen

Sixty-four Thoroughbred and Anglo-Arab mares aged 6-12 years were randomly allocated to 4 dietary groups and fed diets that differed in the total protein content and quality (essential amino-acids). Forty mares were non-lactating and 24 lactating. Eight mares were withdrawn from the investigation owing to injuries or gynaecological pathology. An overall conception rate of 94.6% and a foaling rate of 80% was achieved. Five of 14 (35.7%) mares (Group 1) fed a low-quality protein diet suffered from early embryonic loss before 90 days of pregnancy compared to 3 of 41 (7.3%) mares in the remaining groups that received the higher-quality protein in their diets. Serum progestagen concentrations of mares in Group 1 that suffered foetal loss were indicative of luteal function insufficiency during the 1st 40 days post-ovulation. Non-lactating mares in all 4 groups gained on average approximately 30 kg in mass during the 90 days before the breeding period. Lactating mares in Group 1 (low-quality protein) lost on average 25 kg in mass during lactation, with no weight loss observed among the lactating mares in the other 3 groups. No difference in the diameter of the embryonic vesicle was found between dietary groups until Day 35 of pregnancy.     

Factors concerning early embryonic death in thoroughbred mares in South Korea

A total of 384 Thoroughbred mares were investigated to determine and evaluate the features of early embryonic death at nine equine farms on Jeju Island, South Korea, from 2001 to 2003. Overall, 771 matings for 384 mares resulted in 376 pregnancies 15 days after ovulation. Subsequently, 12.2% (46/376) of these early conceptuses were lost within 45 days after ovulation. Furthermore, about three quarters of the 46 embryonic deaths occurred between 16 and 25 days after ovulation. The incidence of embryonic death was highest in the barren (17.2%), more than 15 years old (15.4%), and more than 10 parities (18.2%) groups compared with the other groups (9.1-16.9%). Mares mated in March, April, and during the first estrus postpartum had higher embryonic death rates, (19.6%, 17.2%, and 24.6%, respectively). Mares with abnormal fluid and cysts in the uterus (18.0%) or multiple embryonic vesicles (23.1%) had higher embryonic death rates than those with normal uterine conditions (9.8%) or single embryonic vesicles (10.5%). The condition of mares, such as breeding condition and the environment of the embryo or fetus, are the major factors in relation to occurrence of early embryonic death.