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1.
Color Doppler and B-mode film clips were taken of the preovulatory follicle an hour before the beginning of ovulation. Locations of serrated granulosa and color-flow signals were determined by clock-face positions with the apex of the follicle (future ovulation site) at 12 o'clock. Mares were divided into a group with normal follicle evacuation (completion within 1 hour; n = 21 mares) and a group with septated evacuation (n = 5). The septated group was characterized by completion of evacuation in ≥3 hours and formation of echoic trabeculae in the antrum during evacuation. The trabeculae in the septated evacuations contained blood-flow signals and were interpreted to be creases in the slowly collapsing follicle wall. In the normal-evacuation group, serration and blood-flow signals were located at the basal hemisphere of the follicle directly opposite to the apex, and the o'clock positions did not differ significantly between the two characteristics. The apical area was devoid of both serration and color-flow signals. Vascularization of the corpus luteum began at the basal third on the day of ovulation and reached the apical third in a mean of 5.5 days. In septated evacuation, color-flow signals were detected at every clock-face position in each mare at the hour before ovulation. Results supported the following hypotheses: (1) both granulosa serration and color-flow signals occur in a similar basal area opposite to the apex; and (2) prolonged septated follicle evacuation is associated with vascularization of a greater circumference of the follicle than for normal evacuation and includes the apical area.  相似文献   

2.
The incidence of hemorrhagic anovulatory follicles (HAFs) is approximately 5% and 20% of estrous cycles during the early and late ovulatory season, respectively. The structures are more common in old mares (eg, >20 years), tend to occur repeatedly in individuals, and occur most frequently during the late follicular phase. In a recent study, the day of ovulation in controls and the first day of HAF formation, as indicated by cloudiness of follicular fluid, were defined as day 0. On day -1, future ovulating and HAF groups did not differ in follicle diameter or in the frequency of discrete gray-scale ultrasonic indicators of impending ovulation; however, in future HAFs, a greater percentage of the circumference of the follicle exhibited color-Doppler signals of blood flow. No differences were found between the two groups in systemic concentrations of progesterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) on days -4 to 2, but estradiol was elevated in the HAF group on day -3. The wall of the HAFs developed well-vascularized luteal tissue as indicated by echotexture and color Doppler signals and by the production of near normal levels of progesterone. In conclusion, HAFs formed from viable preovulatory follicles that did not differ from ovulatory follicles in diameter or gray-scale echotexture. Estradiol concentrations were elevated a few days before the failure of ovulation, and the wall of the follicle was more extensively vascularized on day -1.  相似文献   

3.
The objective of this study was to find difference in vascular perfusion of uterine horns or uterine body throughout the estrous cycle and their relation to circulating nitric oxide and leptin concentrations. Five cyclic mares were subjected to transrectal Doppler ultrasonography and blood sampling for 18 days. Area of color and power Doppler modes was measured in pixels. Day (P = .0001) of the estrous cycle and ovulation (P = .0001) influenced uterine blood flow. Uterine body blood flow directed away from the transducer (blue, P = .0001) increased from day −5 until day 0 (day of ovulation), and its power (P = .0001) blood flow increased from day −6 until day 0; then, both decreased until days 12 and 10, respectively. Conversely to the contralateral uterine horn, ipsilateral uterine horn blood flow directed away from the transducer (blue, P = .0001) increased from day −5 until day −1, and its power (P = .0001) blood flow increased from day −6 until day 0; then, both decreased until day 10. Nitric oxide concentrations (P = .0001) attained two major peaks; the first on day −3 and the other persisted from day 2 until day 5. Leptin concentrations increased (P > .001) with a maximum value on day 0 and then decreased until a minimum value on day 9. In conclusion, during the estrous cycle, ipsilateral uterine horn and uterine body blood vessels had similar blood flow. Both leptin and nitric oxide played a role during follicle growth, ovulation, and corpus luteum development and modulated uterine blood flow before and after ovulation.  相似文献   

4.
In a previous study, times from parturition to the first ovulation were followed in 55 Finnhorse mares on the basis of milk progesterone determinations. Ninety-six per cent of mares had ovulated by day 20 post-partum. If intervals of more than 19 days are excluded from the data, the time from parturition to 1st ovulation was 117 days. However, in cases of foaling before and after the beginning of June the times were 13.0 days and 8.8 days, respectively (p less than 0.001). Long intervals (over 16 days) occurred mainly before 1st May (in 6 out of 7 cases). In a 2nd study, 25 post-partum Finnhorse mares were examined by rectal palpation and ultrasonic scanning. Five and 7 days post partum, but not 2 days post partum there was a statistically significant difference between ovulatory ovaries and non-ovulatory ovaries regarding size of whole ovary and the largest follicle. Six to 8 days before the first post-partum ovulation, the size of the preovulatory follicle was greater in mares which had foaled before the middle of May (32 mm) than in those which had foaled after the middle of May (20 mm) (p less than 0.05). Within 2 days before ovulation there was no statistical difference between the sizes (43 mm and 42 mm, respectively). The growth rate was therefore slower in cases of early foaling (1.8 mm/day) than in cases of late foaling (3.7 mm/day).  相似文献   

5.
The period of spring transition, from the anovulatory to the ovulatory season, is characterized in many mares by cyclical growth and regression of large dominant follicles. These follicles produce only low concentrations of estradiol and it is thought that acquisition of steroidogenic competence by large follicles during spring transition is prerequisite in stimulating LH prior to first ovulation. In situ hybridization was used to localize and quantify expression of factors that play a key role in follicular steroidogenesis: StAR, P450scc (CYP11A1), P450c17 (CYP17), P450arom (CYP19), and LH receptor (LHr). One ovary was obtained from mares on the day after detection of an actively growing 30 mm transitional anovulatory follicle (defined as the transitional follicle), and the remaining ovary was removed at the third estrus of the breeding season on the day after the preovulatory follicle reached 30 mm in diameter (defined as the preovulatory follicle). Messenger RNAs encoding StAR, CYP11A1, and CYP17 were detected only in theca cells and CYP19 mRNA was confined to the granulosa layer. There was significantly lower expression of mRNAs for the steroidogenic enzymes, StAR (P<0.001) and LHr (P<0.05) in transitional follicles than in preovulatory follicles. In conclusion, large equine follicles during spring transition have low levels of mRNA encoding steroidogenic enzymes, StAR and LHr which will contribute to the steroidogenic incompetence of dominant follicles during spring transition and their subsequent regression.  相似文献   

6.
Changes in appearance of preovulatory follicles were observed with real-time ultrasonography prior to and during ovulation in mares. Preovulatory follicles of 15 mares were scanned at < 1 hr intervals for 12 hr or more frequently if displaying signs of impending ovulation. If ovulation was not imminent at the end of 12 hr (n = 2), mares were removed from the trial. Mean follicular diameter decreased 13% from 30 minutes prior to ovulation until the beginning of ovulation. Fifteen to 77 minutes (mean = 41 min) prior to ovulation, a break in or a protrusion of the follicular wall toward the ovulation fossa was visualized in all follicles and was a consistent indicator of impending ovulation. A rapid decrease in size of follicles (ovulation) occurred within a period of 5 to 90 seconds (mean = 42 sec). Little or no fluid remained in the antrum following ovulation. An increase in echogenicity (whiteness) of the follicular wall and echogenic “spots” within the follicle were frequently visualized (13/13, 100% and 7/13, 54% respectively) prior to ovulation; however, prediction of time of ovulation could not be based solely on these individual changes.  相似文献   

7.
With the objective of controlling the day of ovulation, 40 mares were assigned to a control or three treated groups: A3d, A4d, and A5d. The treated groups received antarelix (Teverelix 0.01 mg/kg, i.v., twice a day) for 3, 4, or 5 days from the day the dominant follicle (F1) reached 28 mm (=D0), and one injection of hCG (1600 IU, i.v.) on D1, D2, or D3, respectively. Control mares received one injection of hCG when F1 reached 35 mm. Plasma LH, FSH, progesterone, and total estrogens were assayed. In the A3d, A4d, and A5d groups, 9 (90%), 6 (60%), and 5 (50%) out of 10 mares, respectively, ovulated on the expected day (i.e. between 24 and 48 h after hCG injection). In the control group, 7/10 (70%) presented the typical response to hCG. For 3 mares in both the A4d and A5d groups, the dominant follicle at the time the treatment was started did not ovulate and ovulation was postponed for between 11 and 15 days after the end of treatment. In the treated mares, the LH surge was abolished, and total estrogens were depressed during the preovulatory peak but the concentrations of FSH were not modified. Endocrine parameters were not altered in postponed cycles. Fertility did not differ in treated and control cycles. These results demonstrate that in mares: (1) ovulation can be programmed on a specific day of a 3-day period, with a success rate of 67%, by a treatment associating antarelix and one injection of hCG; (2) nevertheless in 20% of cases the dominant follicle regresses and does not ovulate; (3) for these mares ovulation is postponed by approximately 2 weeks; (4) terminal growth of the preovulatory follicle only requires low circulating concentrations of LH but atresia induced by a GnRH antagonist is significant when this treatment is administrated for more than 18 h.  相似文献   

8.
One of the most profound theriogenology applications of transrectal diagnostic ultrasonography in mares involves the imaging of ovarian follicles and corpora lutea. The resolving capabilities (frequency) and quality of the scanner directly affect the minimal size of a structure that can be imaged and the quality of the image. High-frequency scanners (5 or 7.5 MHz) of good quality can image a 2-mm follicle and the corpus luteum throughout its functional life. A low-frequency scanner (3 or 3.5 MHz) can image a 6-mm follicle and the corpus luteum for several days after ovulation. Equine follicles are excellent subjects for transrectal imaging because they are large, filled with fluid, and readily accessible. Event the small follicles (less than 10 mm) can be diagnostically important in evaluating whether ovarian infertility has occurred and whether the follicles are responding to treatment for follicular stimulation. The large, preovulatory follicles are of special interest. Averaged over a group of 79 periods, the following significant changes were found in the preovulatory follicle: increasing diameter, shape change from spherical to pear-shaped or conical, and increasing thickness of the follicular wall. No significant changes were found in the echogenicity (gray-scale value) of the wall or fluid. In retrospect, the diameter of the follicle seemed as useful for predicting impending ovulation as any of the other ultrasound criteria. The occurrence of ovulation is readily detected by the disappearance of a large follicle that was present at a recent previous examination. In addition, the ovulation site on the day of ovulation is detectable. In one study, the site was correctly identified in 24 of 24 mares. A small amount of residual follicular fluid can sometimes (7 of 10 in one study) be detected at the site of ovulation. The residual fluid usually disappears over a period of 0.5 to 20 hours. Subsequently, the developing corpus luteum may form a central nonechogenic area with peripheral luteinization or may remain uniformly luteinized. The central areas are of apparently vascular origin (blood or a component of blood) and become clotted and organized. In one study, approximately 50 per cent of the glands developed central areas exceeding 10 per cent of the size of the gland. The central areas began to develop on Day 0 or 1 and continued to enlarge until Day 2 or 3. The relative proportion of the gland containing a central clot decreases after Day 3, but the central area usually remains visible throughout diestrus.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   

9.
The aim of this study was to predict the ovulation in mares by quantitative analysis of the echotextural changes of preovulatory follicular walls. Four mares of breeding age with 32 preovulatory follicles and 11 anovulatory follicles were observed by ultrasonography. The slope of the regression line of the follicular wall and the echogenicity score of granulosa layer (GL) and anechoic layer (AL) were measured from the images on Days -3 (Day 0 = ovulation), -2, and -1, respectively. GL was scored from 1 (anechoic) to 3 (echoic), and prominence of AL was recorded from 1 (gray and thin) to 3 (black and thick). The results indicated that the regression line of the follicular wall for 81.3% (26/32) of preovulatory follicles had the slope value ≥19.0 on Day -1, in which 4 of the 26 preovulatory follicles were ≥19.0 on Day -2 already. Mean slope value on Day -1 (21.9 ± 1.5) was significantly greater (P < .01) than on Day -2 (15.0 ± 1.4) and Day -3 (14.0 ± 1.1). All of the slope values for the 11 anovulatory follicles were <19.0 on any given day. GL and AL scores of preovulatory follicles were significantly greater (P < .01) than in anovulatory follicles on Days -3, -2 and -1; nevertheless, only 28.1% (9/32) of preovulatory follicles scored 3 for both GL and AL simultaneously on Day -1. All anovulatory follicles scored <2 for both GL and AL on Day -1. It was concluded that the slope of the regression line of the follicular wall is useful in predicting preovulatory follicles within 48 hours of ovulation when the value is ≥19.0. Of these follicles (N = 26), 84.6% (22/26) were predicted to ovulate within 24 hours, and 15.4% (4/26) within 24 to 48 hours.

Introduction

Insemination in mares by accurately predicting the time of ovulation may obtain maximum fertility with minimum use of semen, and therefore would definitely be a profitable advantage in the horse farming business. The optimal time for insemination with frozen-thawed semen usually include a shorter interval than if fresh semen or natural breeding is used. To achieve the maximal pregnancy rates with frozen-thawed semen, it is necessary to inseminate mares during a period between 12 hours pre- and 6 hours post-ovulation.[1] Therefore, if the timing of ovulation could be predicted, it would be helpful for the veterinarian to inseminate a mare only once per cycle if performed very close to the time of ovulation. [2] In recent years, many indicators have been reported for predicting impending ovulation in mares, including measurement of electrical resistance of the vaginal mucus, [3] the distinguishable endometrial folding pattern of uterus in estrus, [4] changes in size and shape of the preovulatory follicles, [5, 6 and 7] and the echotexture changes in the preovulatory follicular wall. [8] The latter has been more efficient for predicting the imminence of ovulation; nevertheless, their assessment of criterions was scored subjectively. The hypothesis for this study was based on the published report from Gastal et al in 1998 [8]; they found that 2 echotexture changes of the preovulatory follicle-increasing echogenicity of the granulosa layer and increasing prominence of an anechoic layer beneath the granulosa, were detected in the follicular wall as ovulation approached in mares. Computer-assisted image analysis is an advanced technology for diagnostic ultrasonography to improve the reproductive management of patients. [9, 10 and 11] The purpose of this study is to quantify the echotextural changes in the preovulatory follicular wall as ovulation approaches using computer-assisted image analysis, so that the quantified echotexture changes could serve as an indicator for prediction of ovulation in mares.

Materials and Methods

Animals and Ultrasonography

Four non-lactating and nonpregnant mixed mares between 4 and 14 years of age and weighing between 450 and 550 kg were studied from January to December 2001. The geographic area of the mares in this study was in subtropical Taiwan of the northern hemisphere. All mares were maintained on alfalfa/grass hay and had access to water and mineralized salt. A teaser stallion was introduced to detect the estrus signs of mares about 2 weeks after the end of the last estrus. Follicular changes were monitored with a real-time B-mode linear assay ultrasound scanner, equipped with a 7.5-MHz transrectal probe (Model Scanner 200 Vet, Pie Medical, The Netherlands). Upon detection of a preovulatory follicle, ultrasound examination was performed daily and continued until ovulation. A total of 32 preovulatory follicles and 11 anovulatory follicles were identified from a retrospective determination.Ultrasonographic images were recorded on Hi-8 MP videotape with a Sony DCR-TRV 120 Digital-8 camera. The brightness and contrast controls of the monitor and the time-gain compensation of the scanner were standardized to constant settings throughout the observation period.

Image Analysis

Still images were subsequently captured and saved as TIF files by computer using a digital image analysis program (Image-Pro Express V4.0 for Windows, Media Cybernetics, L.P., USA) with a resolution of 640 × 480 pixels and 256 shades of gray. Echotexture of the regions of interest was defined in terms of pixel intensity ranging from 0 (black) to 255 (white). Three ultrasonographic images of each preovulatory follicle at its distinctly discernible cross section were subsequently selected. To avoid the enhancement of through-transmission, sampling regions were located within the 10 or 2 o'clock position for measurement of pixel values (Fig 1). The pixel values were measured with the “Line Profile” tool, which involved sampling pixel values along a line traversing the follicle wall from the peripheral antrum, GL, AL, to the stroma. A graph of the pixel intensities along the line was produced ( Fig 2). The GL was defined as the highest pixel after which there was a sequential fall in gray-scale values. The pixel values along the curve (P0, P1, P2) were obtained as an average of 9 measurements (3 images per follicle and 3 lines per image) and were used to measure the slope of a regression line of the fall segment ( Fig 2).  相似文献   

10.
The use of equine FSH (eFSH) for inducing follicular development and ovulation in transitional mares was evaluated. Twenty-seven mares, from 3 to 15 years of age, were examined during the months of August and September 2004, in Brazil. Ultrasound evaluations were performed during 2 weeks before the start of the experiment to confirm transitional characteristics (no follicles larger than 25 mm and no corpus luteum [CL] present). After this period, as the mares obtained a follicle of at least 25 mm, they were assigned to one of two groups: (1) control group, untreated; (2) treated with 12.5 mg eFSH, 2 times per day, until at least half of all follicles larger than 30 mm had reached 35 mm. Follicular activity of all mares was monitored. When most of the follicles from treated mares and a single follicle from control mares acquired a preovulatory size (≥35 mm), 2,500 IU human chorionic gonadotropin (hCG) was administered IV to induce ovulation. After hCG administration, the mares were inseminated with fresh semen every other day until ovulation. Ultrasound examinations continued until detection of the last ovulation, and embryo recovery was performed 7 to 8 days after ovulation. The mares of the treated group reached the first preovulatory follicle (4.1 ± 1.0 vs 14.9 ± 10.8 days) and ovulated before untreated mares (6.6 ± 1.2 vs 18.0 ± 11.1 days; P < .05). All mares were treated with prostaglandin F2α (PGF2α), on the day of embryo flushing. Three superovulated mares did not cycle immediately after PGF2α treatment, and consequently had a longer interovulatory interval (22.4 vs 10.9 days, P < 0.05). The mean period of treatment was 4.79 ± 1.07 days and 85.71% of mares had multiple ovulations. The number of ovulations (5.6 vs 1.0) and embryos (2.0 vs 0.7) per mare were higher (P < 0.05) for treated mares than control mares. In conclusion, treatment with eFSH was effective in hastening the onset of the breeding season, inducing multiple ovulations, and increasing embryo production in transitional mares. This is the first report showing the use of FSH treatment to recover embryos from the first cycle of the year.  相似文献   

11.
Estrogen from a growing follicle stimulates the preovulatory surge of luteinizing hormone (LH) while progesterone (P) is known to suppress LH. The possibility exists that administration of P, in the presence of an ovulatory follicle, would sufficiently suppress LH and, therefore, delay ovulation. The objective of this research was to elucidate the potential for oral administration of altrenogest (17-Allyl-17β-hydroxyestra-4,9,11-trien-3-one) to postpone ovulation of a preovulatory follicle (35 mm) for approximately two days. Fourteen light-horse mares, ranging in age from two to 19 years, were randomly assigned to one of three treatments (A-.044 mg/kg BW altrenogest for two days; B-.088 mg/kg BW altrenogest for two days; and C- no altrenogest). Mares began treatment when a 35-mm or greater follicle was observed via real-time transrectal ultrasonography. Both number of days until ovulation and follicular maintenance differed between treated and control mares. Number of days until ovulation was increased (P<.05) for mares in treatment A when compared with the control mares. Follicular diameter maintenance, a measurement of follicular diameter throughout treatment, also increased (P<.05) for mares in treatment A when compared with the control mares. Mean LH concentration was not different between mares treated with altrenogest at either treatment dose when compared with the control mares. Pregnancy rates and embryonic vesicle size change were also measured to determine potential effects of altrenogest administration. No differences (P>.05) were found in either characteristic.Short-term administration of altrenogest increased the number of days to ovulation. Further study is warranted to prove conclusively that altrenogest increases follicular maintenance, alters the preovulatory LH surge, and has no detrimental effects upon reproductive efficiency.  相似文献   

12.
The GnRH antagonist antarelix (Teverelix™) was administered to mares (0.01 mg/kg, i.v., twice a day) during the periovulatory period. In Experiment 1, 20 mares were divided into a treated (A3d−) and a control (Control−) group. A3d− mares received antarelix for 3 days from the day when the dominant follicle (F1) reached 32 mm (D0). In Experiment 2, 10 mares were divided into a treated (A6d+) and a control (Control+) group. A6d+ mares received antarelix for 6 days from D0 and hCG was injected in all animals (1600 IU, i.v.) on D1. Pregnancies were determined 13 days after ovulation. In both experiments, antarelix interrupted or totally abolished the LH surge. In Experiment 1, 5/10 of the A3d− mares (with maximum LH concentrations of 11.6 ng/ml at the beginning of treatment) ovulated at the same time as the Control− mares; the other five mares (with LH concentrations under 5.4 ng/ml) ovulated 13.4±0.6 days later. In Experiment 2, all the A6d+ mares ovulated at the same time as the Control+ mares. In treated mares which ovulated during the treatment, progesterone concentrations and fertility did not differ from control mares. These results demonstrate that in mares: (1) a small elevation of endogenous LH can induce ovulation, (2) ovulation can be postponed approximately 13 days after a 3-day antarelix treatment if initiated just before the preovulatory LH surge, (3) ovulation can be induced by hCG on depressed levels of endogenous LH, (4) the inhibition of the post ovulatory LH surge has no effect either on the corpus luteum or on fertility.  相似文献   

13.
The incidence of discrete structural changes in the preovulatory follicle as ovulation approaches was studied sequentially by ultrasonography. Examinations were done every 12 hours in 27 mares, beginning when the follicle was ≥35 mm. The following discrete end points were recorded as present or absent: 1) serration of granulosa, indicated by an irregular or notched appearance; 2) decreased turgidity, indicated during transducer pressure; 3) loss of spherical shape; 4) an apex, indicated by a reduced area at one end; and 5) echoic spots floating in the antrum. When the records were examined as though scanning had been done only every 24 hours beginning at 35 mm, distinct serration was detected at the examination before ovulation in 37% of mares but not earlier. When mares were examined every 12 hours, serration was detected at the last examination in 59%. Decreased turgidity at the last 12-hour examination was detected concomitantly with serration, but was detected alone in 9% to 12% of previous examinations. Mares with serration at the last examination at 12-hour intervals were examined every hour thereafter (n = 14). Serration and decreased turgidity were present at each examination until ovulation 4.9 ± 0.7 hours later. Loss of spherical shape initially occurred less frequently than decreased turgidity, but the incidence increased from 50% to 100% during 6 to 1 hours before ovulation. The incidence of an apical area reached 100%, and echoic spots increased to 50% during the few hours before ovulation. Results indicated that serrated granulosa and the other discrete indicators were useful for predicting impending ovulation; however, optimal efficiency would require examinations every few hours.  相似文献   

14.
Recent studies (2005–2008) on the interrelationships among the preovulatory follicle and periovulatory circulating hormones are reviewed. Close temporal and mechanistic relationships occur between estradiol/inhibin and follicle-stimulating hormone (FSH), between estradiol and luteinizing hormone (LH), and between progesterone and LH. Estradiol from the dominant follicle forms a surge that reaches a peak 2 days before ovulation. Estradiol, as well as inhibin, has a negative effect on FSH, and estradiol has a negative effect on LH. When estradiol decreases, the negative effect diminishes and accounts for the beginning of an FSH increase and a transition from a slow to rapid increase in LH on the day of the estradiol peak. The decrease in estradiol and the reduction or cessation in the growth of the preovulatory follicle beginning 2 days before ovulation are attributable to the development of a reciprocal negative effect of LH on follicle estradiol production when LH reaches a critical concentration. The LH decrease after the peak of the LH surge on the day after ovulation is related to a negative effect of a postovulatory increase in progesterone. Measurable repeatability within mares between consecutive estrous cycles occurs during the preovulatory period in diameter of the ovulatory follicle and concentrations of LH and FSH. Hormone-laden follicular fluid passes into the peritoneal cavity at ovulation and transiently alters the circulating concentrations of LH and FSH. Double ovulations are associated with greater estradiol concentrations and reduced concentrations of FSH.  相似文献   

15.
Characteristics of regular and irregular ovarian events were studied by daily ultrasound examination in 102 non-bred mares. The mean diameter of the prevoluatory follicle on the day before a single ovulation was significantly higher in April (46 mm) and May (48 mm) than in July (40 mm). Diameter was also significantly different among single (44 mm), double unilateral (35 mm), and double bilateral (40 mm) preovulatory follicles. The incidence of apparent anovulation within the ovulatory season was 4.7%. All apparent anovulations involved filling of the follicle with blood (hemorrhagic follicles). The incidence of diestrous ovulations was 4%. Prolonged interovulatory intervals occurred in 6 of 69 (9%) intervals. In 2 intervals (30 and 33 days), both the luteal and follicular phases were prolonged and no structural ovarian or uterine irregularities were detected. Three prolonged intervals (34, 41, and 49 days) were associated with hemorrhagic follicles and 1 was associated with a late diestrous ovulation (47 days). The condition known as spontaneous persistence of the corpus luteum, which is thought to be common in nonpregnant mares, was not detected in any of 69 interovulatory intervals.  相似文献   

16.
The purpose of this research was to determine whether treatment with varying doses of recombinant equine follicle stimulating hormone (reFSH) stimulates the development of multiple follicles and ovulations and increases the number of embryos recovered in the mare. Therefore, because reFSH can be cloned in repeatable, sizeable quantities, it could be used as a tool to enhance superovulation in mares. In experiment 1, the number of preovulatory follicles, ovulations, and embryos recovered per flush was greater in the 0.85 mg reFSH group than in the control group; however, the embryo per ovulation rates were similar. Plasma inhibin and estradiol concentrations were greater in treated mares around the time of ovulation as compared with the control group, whereas concentrations of luteinizing hormone remained low throughout the treatment, ovulation, and postovulation. In treated mares, concentrations of follicle stimulating hormone increased during therapy and before ovulation, but decreased postovulation. In experiment 2, varying doses of reFSH (0.35, 0.50, and 0.65 mg) and 12.5 mg of Bioniche equine follicle stimulating hormone (eFSH) increased the number of preovulatory follicles as compared with control group. The greatest number of ovulations was induced by treatment with 12.5 mg eFSH, 0.5 mg reFSH, and 0.65 mg reFSH. The highest number of embryos recovered per flush was found with treatments of eFSH and 0.65 mg reFSH. However, the embryo per ovulation rates were similar in all treatment groups, including the control group. In experiment 3, reFSH (0.5 and 0.85 mg) and eFSH (12.5 mg) given twice daily showed a similar increase in the number of pre-ovulatory follicles and ovulations. A single daily treatment of reFSH (0.85 mg) as well as the twice daily dose of eFSH was determined to increase follicular activity. In conclusion, reFSH was as effective as eFSH in increasing the number of follicles ≥35 mm, ovulation rates, and embryo recovery rates per flush compared with the control group.  相似文献   

17.
Strategies for Using eFSH for Superovulating Mares   总被引：1，自引：0，他引：1  
The standard treatment for superovulation of mares is to administer equine follicle-stimulating hormone (eFSH) for 4 to 5 days to stimulate multiple follicles and human chorionic gonadotropin (hCG) to induce synchronous ovulations. Objectives of this study were: (1) to determine whether a short-term (3-day) eFSH treatment protocol would result in similar ovulation and embryo recovery rates compared with the standard eFSH protocol; (2) to determine the efficacy of a decreasing dose of eFSH (step-down protocol) on ovulation rate and embryo recovery; (3) to compare the efficacy of hCG and recombinant equine luteinizing hormone (reLH) for inducing ovulation in FSH-treated mares; and (4) to compare embryo recovery rates and embryo size when mares are flushed at 6.5 or 7.0 days after ovulation. Forty light-horse mares were used in 2005 (experiment 1) and 20 different mares were used in 2006 (experiment 2). In experiment 1, mares were randomly assigned to one of three treatment groups: (1) untreated controls, (2) standard eFSH treatment (12.5 mg intramuscularly twice daily), and (3) 3-day eFSH treatment. In experiment 2, mares were randomly assigned to one of four treatments: (1) untreated controls, (2) standard eFSH protocol, (3) 3-day eFSH treatment, and (4) step-down eFSH treatment (12.5 mg twice daily day 1, 8.0 mg twice daily day 2, 4.0 mg twice daily day 3). Within each treatment, mares were given either hCG (2,500 IU) or equine LH (750 mg, EquiPure LH; reLH) to induce synchronized ovulations. Embryo recovery was performed either 6.5 or 7.0 days after ovulation. In experiment 1, numbers of preovulatory follicles and ovulations were less for mares in the 3-day treatment group than the standard group, but were greater than for controls. Embryo recovery per flush was higher in the standard group (2.6) than the 3-day eFSH treatment (0.8) or control groups (0.8). In experiment 2, the number of preovulatory follicles and number of ovulations were greater in the standard and 3-day treatment groups than in control and step-down groups. The percent embryo recovery per ovulation and mean embryo grade were similar for all groups; however, the embryo recovery per flush was higher for mares in the standard treatment than controls (1.3 vs 0.6) but was similar to the 3-day (1.1) and step-down (0.8) treatments. Embryo recovery was similar for flushes performed on days 6.5 and 7.0 post-ovulation. The percentage of control mares ovulating within 48 hours in response to hCG or reLH was similar. In contrast, a higher percentage of eFSH-treated mares ovulated within 48 hours in response to reLH than hCG (92% vs 71%). In both years, the 3-day eFSH treatment protocol resulted in a greater number of preovulatory follicles and a greater number of ovulations than untreated controls. Unfortunately, the increased ovulation rate for mares administered eFSH for 3 days did not result in a greater number of embryos recovered per flush in either year. Use of a step-down eFSH treatment protocol resulted in fewer preovulatory follicles, fewer ovulations, and fewer embryos as compared with the standard eFSH treatment. In conclusion, the standard eFSH treatment resulted in a greater embryo recovery rate per cycle than either the 3-day or step-down treatment protocols. Recombinant equine LH was more effective than hCG in causing ovulation in eFSH-treated mares.  相似文献   

18.
The present experiment characterized the pituitary responsiveness to exogenous GnRH in the first 10 d after ovulation following commercially available deslorelin acetate implantation at the normal dosage for hastening ovulation in mares. Twelve mature, cyclic mares were assessed daily for estrus and three times weekly for ovarian activity starting May 1. Mares achieving a follicle at least 25 mm in diameter or showing signs of estrus were checked daily thereafter for ovarian characteristics. When a follicle >30 mm was detected, mares were administered either a single deslorelin acetate implant or a sham injection and then assessed daily for ovulation. On d 1, 4, 7, and 10 following ovulation, each mare was challenged i.v. with 50 microg GnRH, and blood samples were collected to characterize the LH and FSH responses. The size of the largest follicle on the day of treatment did not differ (P = 0.89) between groups. The number of days from treatment to ovulation was shorter (P < 0.001) by 2.0 d for the treated mares indicating a hastening of ovulation. The size of the largest follicle present on the days of GnRH challenge was larger in the treated mares on d 1 (P = 0.007) but smaller on d 10 (P = 0.02). In addition, the interovulatory interval was longer (P = 0.036) in the treated mares relative to controls by 4.4 d. Concentrations of FSH in plasma of the treated mares were lower (P < 0.05) than control concentrations from d 3 to 12; LH concentrations in the treated mares were lower (P < 0.05) relative to controls on d 0 to 5, d 7, and again on d 20 to 23. Progesterone values were the same (P = 0.99) for both groups from 2 d before ovulation though d 23. There was an interaction of treatment, day, and time of sampling (P < 0.001) for LH and FSH concentrations after injection of GnRH. Both the LH and FSH responses were suppressed (P < 0.009) in the treated mares relative to controls on d 1, 4, and 7; by d 10, the responses of the two groups were equivalent. In conclusion, deslorelin administration in this manner increased the interovulatory interval, consistently suppressed plasma LH and FSH concentrations, and resulted in a complete lack of responsiveness of LH and FSH to GnRH stimulation at the dose used during the first 7 d after the induced ovulation. Together, these results are consistent with a temporary down-regulation of the pituitary gland in response to deslorelin administered in this manner.  相似文献   

19.
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.  相似文献   

20.
To investigate the ovarian and uterine blood flow responses, hemodynamic, circulating ovarian hormones and nitric oxide (NO) after end of treatment by Folltropin. Holstein Friesian (12) cows previously synchronized with CIDR underwent Doppler ultrasound after administrating of FSH daily for 4 days in eight injections started on day 10 of the second ovulation (day −5). Oestradiol (E2), progesterone (P4) and nitric oxide (NOMs) were measured. During the follicular phase, follicle area and antrum area of the second cycle reached maximum value on the day of ovulation compared with that in the first cycle, while during the luteal phase, both showed a pattern of increase and decrease. The luteal area and total coloured area increased till day 10 in the first and second cycle. The first cycle ipsilateral ovarian artery (Ov.A) had higher pulsatility (PI) (p = .001), resistance (RI) (p = .001), peak velocity (PSV) (p = .009) and lower end-diastolic velocity (EDV) (p = .003) compared with the second cycle. The increased ipsilateral Ov.A PSV (p = .009) was accompanied by lower EDV. The first cycle ipsilateral middle uterine artery (MUA) had higher PI (p = .001) and RI (p = .001), with lower PSV (p = .001) and EDV (p = .001). It was concluded that blood flow of ovarian and middle uterine arteries changed after the end of superstimulation as the increased ipsilateral Ov. A and MUA PSVs accompanied by lower EDV and both Doppler indices that reflect the amount of ovarian and uterine blood flow waveform.  相似文献   

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