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1.
Equine clinicians rely on ovulation induction agents to provide a timed ovulation in mares for optimal breeding management. Numerous studies have been performed on the efficacy of human chorionic gonadotropin (hCG) to induce ovulation in the mare, but limited clinical data are available for the new deslorelin acetate product SucroMate. This study was designed to evaluate the efficacy of SucroMate (deslorelin) in comparison with hCG to induce ovulation. American Quarter horse mares (n = 256) presented to Colorado State University for breeding management were used in this study. Mares received either deslorelin or hCG when a follicle ≥35 mm was detected by transrectal ultrasound in the presence of uterine edema. Ultrasonographic examinations were subsequently performed once daily until ovulation was detected. Deslorelin was administered to 138 mares during168 estrous cycles, and hCG was given to 118 mares during 136 estrous cycles. Mares administered deslorelin had a similar (P < .05) higher ovulation rate (89.9%) within 48 hours following drug administration than mares administered hCG (82.8%). There are no effects of season or age on ovulation rates in either treatment group. Twenty-one mares administered deslorelin and 11 mares administered hCG were monitored by transrectal ultrasound every 6 hours to detect ovulation as part of a frozen semen management program. Average intervals from deslorelin or hCG administration to ovulation were 41.4 ± 9.4 and 44.4 ± 16.5 hours, respectively. Results of this study indicate that SucroMate is effective at inducing a timed ovulation in the mare.  相似文献   

2.
The objective of this study was to compare the rate of ovulation when deslorelin and/or human chorionic gonadotropin (hCG) was administered in mares in both the transition period and the ovulatory season. A total of 200 Paint Horses, Quarter Horses, and crossbred mares were used during the transition season (July to September) and the ovulatory season (October to February) of the southern hemisphere. The animals were divided into four groups. In the control group (n = 72), mares received 1 mL of saline; in deslorelin group (n = 171), 1.5 mg of deslorelin was administered by intramuscular (IM) injection; in hCG group (n = 57), 1,667 IU of hCG was administered IV; and in hCG + deslorelin group (n = 438), 1.5 mg of deslorelin (IM) and 1,667 IU of hCG (IV) were administered. The drugs were administered after follicles ≥35 mm in diameter were identified and grade III uterine edema was observed. At 48 hours after application, ultrasonography was performed to detect ovulation. During the transition period, the ovulation rates were 4.3% (control), 78.6% (deslorelin), 50% (hCG), and 73.3% (hCG + deslorelin). During ovulatory season, the ovulation rates were 16.4% (control), 68.8% (deslorelin), 60% (hCG), and 73% (hCG + deslorelin). There was no significant difference (P > .05) in the ovulation rate between the groups or the periods, except that the control group was lower than all others. Furthermore, both hCG and deslorelin are viable options for inducing ovulation during the transition period before ovulation season.  相似文献   

3.
Superovulation would potentially increase the efficiency and decrease the cost of embryo transfer by increasing embryo collection rates. Other potential clinical applications include improving pregnancy rates from frozen semen, treatment of subfertility in stallions and mares, and induction of ovulation in transitional mares. The objective of this study was to evaluate the efficacy of purified equine follicle stimulating hormone (eFSH; Bioniche Animal Health USA, Inc., Athens, GA) in inducing superovulation in cycling mares. In the first experiment, 49 normal, cycling mares were used in a study at Colorado State University. Mares were assigned to 1 of 3 groups: group 1, controls (n = 29) and groups 2 and 3, eFSH-treated (n = 10/group). Treated mares were administered 25 mg of eFSH twice daily beginning 5 or 6 days after ovulation (group 2). Mares received 250 (of cloprostenol on the second day of eFSH treatment. Administration of eFSH continued until the majority of follicles reached a diameter of 35 mm, at which time a deslorelin implant was administered. Group 3 mares (n = 10) received 12 mg of eFSH twice daily starting on day 5 or 6. The treatment regimen was identical to that of group 2. Mares in all 3 groups were bred with semen from 1 of 4 stallions. Pregnancy status was determined at 14 to 16 days after ovulation.In experiment 2, 16 light-horse mares were used during the physiologic breeding season in Brazil. On the first cycle, mares served as controls, and on the second cycle, mares were administered 12 mg of eFSH twice daily until a majority of follicles were 35 mm in diameter, at which time human chorionic gonadotropin (hCG) was administered. Mares were inseminated on both cycles, and embryo collection attempts were performed 7 or 8 days after ovulation.Mares treated with 25 mg of eFSH developed a greater number of follicles (35 mm) and ovulated a greater number of follicles than control mares. However, the number of pregnancies obtained per mare was not different between control mares and those receiving 25 mg of eFSH twice daily. Mares treated with 12 mg of eFSH and administered either hCG or deslorelin also developed more follicles than untreated controls. Mares receiving eFSH followed by hCG ovulated a greater number of follicles than control mares, whereas the number of ovulations from mares receiving eFSH followed by deslorelin was similar to that of control mares. Pregnancy rate for mares induced to ovulate with hCG was higher than that of control mares, whereas the pregnancy rate for eFSH-treated mares induced to ovulate with deslorelin did not differ from that of the controls. Overall, 80% of mares administered eFSH had multiple ovulations compared with 10.3% of the control mares.In experiment 2, the number of large follicles was greater in the eFSH-treated cycle than the previous untreated cycle. In addition, the number of ovulations during the cycle in which mares were treated with eFSH was greater (3.6) than for the control cycle (1.0). The average number of embryos recovered per mare for the eFSH cycle (1.9 ± 0.3) was greater than the embryo recovery rate for the control cycle (0.5 ± 0.3).In summary, the highest ovulation and the highest pregnancy and embryo recovery rates were obtained after administration of 12 mg of eFSH twice daily followed by 2500 IU of hCG. Superovulation with eFSH increased pregnancy rate and embryo recovery rate and, thus, the efficiency of the embryo transfer program.

Introduction

Induction of multiple ovulations or superovulation has been an elusive goal in the mare. Superovulation would potentially increase the efficiency and decrease the cost of embryo transfer by increasing embryo collection rates.[1 and 2] Superovulation also has been suggested as a critical requirement for other types of assisted reproductive technology in the horse, including oocyte transfer and gamete intrafallopian transfer. [2 and 3] Unfortunately, techniques used successfully to superovulate ruminants, such as administration of porcine follicle stimulating hormone and equine chorionic gonadotropin have little effect in the mare. [4 and 5]The most consistent therapy used to induce multiple ovulations in mares has been administration of purified equine pituitary gonadotropins. Equine pituitary extract (EPE) is a purified gonadotropin preparation containing approximately 6% to 10% LH and 2% to 4% FSH.[6] EPE has been used for many years to induce multiple ovulations in mares [7, 8 and 9] and increase the embryo recovery rate from embryo transfer donor mares. [10] Recently, a highly purified equine FSH product has become available commercially.The objectives of this study were to evaluate the efficacy of purified eFSH in inducing superovulation in cycling mares and to determine the relationship between ovulation rate and pregnancy rate or embryo collection rate in superovulated mares.

Materials and methods

Experiment 1

Forty-nine normally cycling mares, ranging in age from 3 to 12 years, were used in a study at Colorado State University. Group 1 (control) mares (n = 29) were examined daily when in estrus by transrectal ultrasonography. Mares were administered an implant containing 2.1 mg deslorelin (Ovuplant, Ft. Dodge Animal Health, Ft. Dodge, IA) subcutaneously in the vulva when a follicle 35 mm in diameter was detected. Mares were bred with frozen semen (800 million spermatozoa; minimum of 30% progressive motility) from 1 of 4 stallions 33 and 48 hours after deslorelin administration. The deslorelin implants were removed after detection of ovulation.[11] Pregnancy status was determined at 14 and 16 days after ovulation.Group 2 mares (n = 10) were administered 25 mg of eFSH (Bioniche Animal Health USA, Inc., Athens, GA) intramuscularly twice daily beginning 5 or 6 days after ovulation was detected. Mares received 250 g cloprostenol (Estrumate, Schering-Plough Animal Health, Omaha, NE) intramuscularly on the second day of eFSH treatment. Administration of eFSH continued until a majority of follicles reached a diameter of 35 mm, at which time a deslorelin implant was administered. Mares were subsequently bred with the same frozen semen used for control mares, and pregnancy examinations were performed as described above.Group 3 mares (n = 10) received 12 mg of eFSH twice daily starting 5 or 6 days after ovulation and were administered 250 μg cloprostenol on the second day of treatment. Mares were randomly selected to receive either a deslorelin implant (n = 5) or 2500 IU of human chorionic gonadotropin (hCG) intravenously (n = 5) to induce ovulation when a majority of follicles reached a diameter of 35 mm. Mares were bred with frozen semen and examined for pregnancy as described above.

Experiment 2

Sixteen cycling light-horse mares were used during the physiologic breeding season in Brazil. Reproductive activity was monitored by transrectal palpation and ultrasonography every 3 days during diestrus and daily during estrus. On the first cycle, mares were administered 2500 IU hCG intravenously once a follicle 35 mm was detected. Mares were subsequently inseminated with pooled fresh semen from 2 stallions (1 billion motile sperm) daily until ovulation was detected. An embryo collection procedure was performed 7 days after ovulation. Mares were subsequently administered cloprostenol, and eFSH treatment was initiated. Mares received 12 mg eFSH twice daily until a majority of follicles were 35 mm in diameter, at which time hCG was administered. Mares were inseminated and embryo collection attempts were performed as described previously.

Statistical analysis

In experiment 1, 1-way analysis of variance with F protected LSD was used to analyze quantitative data. Pregnancies per ovulation were analyzed by x2 analysis. In experiment 2, number of large follicles, ovulation rate, and embryo recovery rate were compared by Student,'s t-test. Data are presented as the mean S.E.M. Differences were considered to be statistically significant at p < .05, unless otherwise indicated.

Results

In experiment 1, mares treated with 25 mg eFSH twice daily developed a greater number of follicles 35 mm in diameter (p = .001) and ovulated a greater number of follicles (p = .003) than control mares (Table 1). However, the number of pregnancies obtained per mare was not significantly different between the control group and the group receiving 25 mg eFSH (p = .9518). Mares treated with 12 mg eFSH and administered either hCG or deslorelin to induce ovulation also developed more follicles 35 mm (p = .0016 and .0003, respectively) than untreated controls. Mares receiving eFSH followed by hCG ovulated a greater number of follicles (p = .003) than control mares, whereas the number of ovulations for mares receiving eFSH followed by deslorelin was similar to that of control mares (p = .3463). Pregnancy rate for mares induced to ovulate with hCG was higher (p = .0119) than that of control mares, whereas the pregnancy rate for eFSH-treated mares induced to ovulate with deslorelin did not differ from that of controls (p = .692). Pregnancy rate per ovulation was not significantly different between control mares (54.5%) and mares treated with eFSH followed by hCG (52.9%). The lowest pregnancy rate per ovulation was for mares stimulated with 25 mg eFSH and induced to ovulate with deslorelin. The mean number of days mares were treated with 25 mg or 12 mg of eFSH was 7.8 ± 0.4 and 7.5 ± 0.5 days, respectively. Overall, 80.0% of mares administered eFSH had multiple ovulations compared with 10.3% of control mares.  相似文献   

4.
The timing of ovulation is an important component to many equine breeding strategies. The action of luteinizing hormone on ovulation induction has been recognized; however, potential effects of follicle-stimulating hormone (FSH) have been less defined. Objectives of this study were to determine whether (1) mares could be induced to ovulate follicles ≤30 mm; (2) equine FSH (eFSH) has a positive effect on ovulation induction, and (3) ovulation of small follicles would affect embryo recovery. Light-horse mares (n = 12) between 4 and 10 years of age were assigned to treatments when they had a dominant growing follicle with a mean diameter of 24, 28, or 35 ± 2 mm and endometrial edema. Treatments were (1) H35, human chorionic gonadotropin (hCG) at 35 ± 2 mm; (2) F35, eFSH at 35 ± 2 mm; (3) H28, hCG at 28 ± 2 mm; (4) FH28, eFSH and hCG at 28 ± 2 mm; (5) D28, deslorelin (gonadotropin-releasing hormone [GnRH] analog) at 28 ± 2 mm; (6) FH24/H24, hCG or eFSH and hCG at 24 ± 2 mm. Mares’ reproductive tracts were scanned at 24 ± 2-hour intervals after treatment to detect ovulation. Mares were inseminated, and embryos were collected. Numbers of mares that ovulated within 48 ± 2 hours after treatment were: H35, 8/8 (100%); F35, 8/14 (57%); H28, 7/12 (58%); FH28, 9/12 (75%); D28, 3/7 (43%) and FH/H24, 4/14 (29%). The number of mares that ovulated in 48 ± 2 hours for H35 was not different from that for FH28 but was higher (P < .05) than all other groups. Embryo recovery rates, diameters, developmental stages, and morphology scores were not different for mares ovulating 48 hours or less versus more than 48 hours after treatment or among treatment groups. Results of this study demonstrate that follicles ≤30 mm can be induced to ovulate with no effect on embryo recovery or quality, as assessed by stereomicroscopy.  相似文献   

5.
Palpation records of 155 Throughbred broodmares maintained on one of seven farms (3–80 mares per farm) that were administered deslorelin on one or more estrous cycles (204 treated cycles) during the 1999 breeding season were retrospectively examined. Some deslorelin-treated mares were also treated with hCG (2500 units intravenously), or had no ovulation-inducing drugs administered, during different estrous cycles of the same season. Most mares were treated with an ovulation- inducing drug after returning to their resident farm following breeding and were subsequently examined by transrectal ultrasonography daily until ovulation was confirmed, and again 13–14 and 15–16 days after ovulation for determination of pregnancy status.Per-cycle pregnancy rate for all 155 mares bred was 53%, and for all deslorelin breeding was 57%. Per-cycle pregnancy rates for mares ovulating 0–1 days, 1–2 days, and 2–3 days after treatment with deslorelin did not differ (P>0.05). Forty-six mares received more than one treatment during the breeding season, yielding 115 breedings (estrous cycles) for comparison of pregnancy rates among treatment. Per-cycle pregnancy rates for these mares did not differ among treatments (P>0.10).No differences due to treatment were detected in mean interval to ovulation (P>0.10). Mean interovulatory interval was longer for deslorelin-treated mares than for untreated or hCG treated mares (P>0.01). Eighty percent (80%) of deslorelin-treated mares had interovulatory intervals of 18–25 days, and 19% had interovulatory intervals>25 days. Ninety-seven percent (97%) of untreated or hCG-treated mares had interovulatory interovulatory intervals>25 days. More deslorelin-treated mares had extended (>25 days) interovulatory intervals than hCG- or nontreated-mares (P>0.05). In this group of Thoroughbred mares, it appeared that season (month) and management (farm) factors had only minor effects on the incidence of extended interovulatory intervals following use of deslorelin.  相似文献   

6.
Breeding records of 48 Thoroughbred and Standardbred mares treated with native GnRH (500μg im, bid) during February—April, 1999 or 2000, on 7 farms in central Kentucky were retrospectively examined. Treated mares were classified as being in anestrus or early transition (n=42; if no signs of estrus occurred within 31/2 weeks and the largest follicle remained ≤25 mm in diameter or the first larger follicle(s) of the season regressed without ovulating), or were classified as being in late transition (n=6; if follicular growth achieved 30-40 mm diameter but ovulation had not yet occurred during the breeding season). Thirty-eight mares (38/48; 79%) ovulated in 13.7 ± 7.4 days. Interval to ovulation was negatively associated with size of follicles at onset of native GnRH therapy (P < 0.01). Per cycle pregnancy rate was 53% (19/36 mares bred). Ovulation inducing drugs were administered to 32 of the native GnRH treated mares (2500 units hCG intravenously, n = 20; deslorelin implant [Ovuplant™] subcutaneously, n=12), while 6 mares were not administered any additional drugs to induce ovulation. Per cycle pregnancy rate did not differ among mares treated only with native GnRH (2/5 mares bred; 40% PR), mares treated with native GnRH plus hCG (12/19 mares bred; 63% PR), or mares treated with native GnRH plus Ovuplant™ (5/12 mares bred; 42% PR) (P > 0.10). Additional treatment with either hCG or Ovuplant™ did not alter mean follicle size at ovulation or interovulatory interval (P > 0.10). The proportion of interovulatory intervals > 25 days was not different between mares receiving no additional treatment to induce ovulation (0/4; 0%) compared to mares receiving hCG to induce ovulation (3/8; 38%) (P > 0.10), but the proportion of interovulatory intervals > 25 days was greater for mares receiving Ovuplant™ to induce ovulation (5/7; 71%) compared to mares receiving no additional treatment to induce ovulation (P < 0.05). The proportion of mares with extended interovulatory intervals (i.e., > 25 days) did not differ between mares with follicles < 15 mm diameter (4/8, 50%) and those with follicles > 15 mm diameter (3/11, 27%) at onset of native GnRH treatment (P > 0.10). While concurrent untreated controls were not used in this study, the 79% response rate to twice daily administration of native GnRH is in agreement with other reports using pulsatile or constant infusion as methods of administration, confirming therapy can hasten follicular development and first ovulation of the breeding season. As with previous reports, follicle size at onset of treatment is an important determinant of interval from onset of native GnRH therapy to ovulation. Use of hCG or Ovuplant™ did not enhance ovulatory response in native GnRH treated mares. Use of Ovuplant™ during native GnRH therapy may increase the incidence of post-treatment anestrus in mares not becoming pregnant.  相似文献   

7.
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   

8.
Our aim was to compare Corpus luteum (CL) development and blood plasma concentration of progesterone ([P4]) in thoroughbred mares after spontaneous (Control: C) or human chorionic gonadotrophin (hCG)‐induced ovulation. Lactating mares (C = 12; hCG = 21) were daily teased and mated during second oestrus post‐partum. Treated mares received 2500 IU hCG i.v. at first day of behavioural oestrus when dominant follicular size was >35, ≤42 mm and mated 12–24 h after. Control mares in oestrus were mated with dominant follicular size ≥45 mm. Dominant follicle before ovulation, CL and gestational sac were measured by ultrasound and [P4] by radioimmunoassay (RIA). Blood sampling and ultrasound CL exams were done at days 1, 2, 3, 4, 8, 12, 16, 20, 25, 30, 35, 40, 45, 60 and 90 after ovulation and gestational sac from day 12 after ovulation in pregnant (P) mares; non‐pregnant (NP) were followed until oestrus returned. Data analyses considered four subgroups: hCG‐P, hCG‐NP, C‐P and C‐NP. Preovulatory follicular size was smaller in hCG mares than in C: 39.2 ± 2.7 mm vs 51.0 ± 1.8 mm (p < 0.0001). All hCG mares ovulated 24–48 h after treatment and presented similar oestrus duration as controls. C. luteum size in P mares showed the same pattern of development through days 4–35, presenting erratic differences during initial establishment. Thus, on days 1 and 3, CL was smaller in hCG‐P (p < 0.05); while in hCG‐NP, CL size was greater than in C‐NP on day three (p = 0.03). Corpus luteum size remained stable until day 90 in hCG‐P mares, while in C‐P a transient and apparently not functional increase was detected on days 40 and 45 (p < 0.05) and the decrease from day 60 onwards, made this difference to disappear. No differences were observed in [P4] pattern between P, or between NP subgroups, respectively. So, hCG‐induced ovulation does not affect CL development, neither [P4] during early pregnancy. One cycle pregnancy rate tended to be lower in hCG mares while season pregnancy rates were similar to controls.  相似文献   

9.
Equine chorionic gonadotropin (eCG), obtained from pregnant mares, is used for assisted reproductive technologies in laboratory rodents and livestock. The objective of the present study was to use equine follicle-stimulating hormone (eFSH) to increase the incidence of twin pregnancies, through multiple ovulations, and increase eCG. Nineteen light horse–type mares were enrolled in the study. The control group (n = 9) was bred with fresh or cooled semen and given human chorionic gonadotropin (hCG) at the time of breeding. The second group (n = 10) was given 12.5 mg of eFSH intramuscularly twice a day beginning 5–7 days after ovulation. Prostaglandin F2α was administered intramuscularly the second day of eFSH treatment. Treatment with eFSH continued until follicles were >35 mm in diameter, and mares were then given no treatment for 36 hours. The mares were then bred with fresh or cooled semen from the same stallion as the control group and given hCG. Blood samples were taken weekly from day 35 to day 105 after ovulation. Serum concentration of eCG was obtained, and data were analyzed with multivariate analysis using the mixed procedure. Significance was set at P < .05. Data were combined for all mares carrying twins and compared with those carrying singletons. The group of mares carrying twins had higher peak concentrations of eCG and higher values for area under the curve compared with mares carrying singletons (P < .05). These results suggest inducing twins could be a method used to increase eCG production.  相似文献   

10.
Exercise stress has a negative impact on embryo transfer efficiency (ET). For example, a 34% embryo recovery rate, 43% incidence of poor quality embryos, and a 29% pregnancy rate after transfer have been reported. Administration of nonsteroidal anti-inflammatory drugs (NSAIDs) may reduce the inflammatory response produced after nonsurgical embryo transfer. In addition, progesterone supplementation is commonly administered to some recipient mares to improve uterine conditions before the transfer and to ensure adequate progestational support compatible with pregnancy. The aim of the study was to evaluate embryo recovery rates using BioRelease deslorelin versus hCG and to increase posttransfer pregnancy rates by jointly administering BioRelease progesterone and a NSAID (flunixin or meloxicam) to recipient mares. Seventeen upper-level showjumping mares stabled and in daily training were used as embryo donors. To induce ovulation, 1-mg IM BioRelease deslorelin (BioRelease Technologies, Lexington, KY) was injected in treated cycles (n = 66), or 2500-IU hCG IV (Ovusyn, Syntex, Buenos Aires, Argentina) was given in control cycles (n = 79) when a ≥35 mm follicle was present. Artificial insemination with extended fresh semen (at least 500 × 106 progressively motile sperm) was carried out in both groups immediately after injecting the ovulation induction agent. Day 8 embryos were recovered and nonsurgically transferred using a speculum and a cervical traction forceps. Recipient mares (n = 73) were randomly assigned to one of three groups: Group A received a single injection of 1.5-g IM BioRelease progesterone (Progesterone LA 300, BioRelease Technologies) and 3 IV injections of 0.5 g of flunixin meglumine (Flunix Deltavet, Argentina), one injection administered the day of the transfer and one on each of the next two successive days. Group B received 1.5-g IM BioRelease progesterone and a single dose of 1.5-g IM BioRelease meloxicam (Meloxicam LA, BioRelease Technologies) at the moment of embryo transfer. Group C did not receive any treatment. Pregnancy diagnosis was carried out 7 days after transfer. Results were analyzed using comparisons of proportions. More embryos were recovered per cycle (13% increase) when donor mares in training were induced to ovulate with BioRelease deslorelin (60.6%; 40/66) than with hCG (46.8%; 37 of 79; P < .05). Although both recipient groups given NSAIDs in combination with BioRelease progesterone numerically had higher pregnancy rates (A: 70.8%; 17/24 and B: 75%; 15/20) compared with nontreated control recipients (47.1%; 33/70), pregnancy rates were significantly higher only in recipients given LA meloxicam treatment at the time of transfer (P < .05). The LA meloxicam is released over a 72-hour period making it more practical to use as it requires a single IM injection versus the 3 IV flunixin meglumine injections. Thus, to minimize the effects of exercise stress on ET efficiency, a combination of BioRelease deslorelin to induce ovulation in donors and BioRelease progesterone and LA meloxicam in recipients at the time of transfer may offer an interesting alternative for improving results in commercial ET programs.  相似文献   

11.
OBJECTIVE: To evaluate gonadotropin secretion and ovarian function after administration of deslorelin acetate to induce ovulation in mares. DESIGN: Randomized controlled trial. ANIMALS: 16 healthy mares with normal estrous cycles. PROCEDURE: 8 control mares were allowed to ovulate spontaneously, whereas 8 study mares received deslorelin to induce ovulation when an ovarian follicle > 35 mm in diameter was detected. Follicle development and serum concentrations of gonadotropins were monitored daily during 1 estrous cycle. Pituitary responsiveness to administration of gonadotropin-releasing hormone (GnRH) was evaluated 10 days after initial ovulation. RESULTS: Interovulatory intervals of mares treated with deslorelin (mean +/- SD, 25.6 +/- 2.6 days) were longer than those of control mares (22.9 +/- 1.8 days). Diameter of the largest follicle was significantly smaller during 2 days of the diestrous period after ovulation in deslorelin-treated mares than in control mares. Concentrations of follicle-stimulating hormone (FSH) were lower in deslorelin-treated mares on days 5 through 14 than in control mares. Concentrations of luteinizing hormone were not different between groups during most of the cycle. Gonadotropin release in response to administration of GnRH was lower in mares treated with deslorelin acetate than in control mares. CONCLUSIONS AND CLINICAL RELEVANCE: Administration of deslorelin was associated with reduction in circulating concentrations of FSH and gonadotropin response to administration of GnRH during the estrous cycle. Low concentration of FSH in treated mares may lead to delayed follicular development and an increased interovulatory interval.  相似文献   

12.
Sixty nonlactating light-horse mares were used to compare the efficacy of hCG, buserelin (a GnRH analog) and luprostiol (a PGF2α analog) for induction of ovulation in cycling mares. Mares were assigned to 1 of 4 treatments: 1) controls; 2) 40 μg buserelin IM at 12 hr intervals during estrus until ovulation; 3) 7.5 mg IM luprostiol; and 4) 3,300 IU hCG. Treatments were given once a mare obtained a ≥35mm follicle and had been in estrus ≥2 days. Both buserelin and hCG shortened (p<0.05) the interval from treatment to ovulation compared to controls; whereas, luprostiol failed to hasten ovulation. Number of follicles ovulated was similar among all 4 groups. Although buserelin and hCG were equal in their ability to induce ovulation, an average of 3.8 injections of buserelin was required for hastening of ovulation.  相似文献   

13.
Over four years, four investigators in the Northern Hemisphere treated 413 privately owned transition phase mares between late February and early April, for the purpose of breeding such mares early in the season. Mares received an intravaginal device (CIDR-B) carrying 1.9 g progesterone, for about 12 days. Thereafter mares forming preovulatory follicles >30 mm were either treated with a short acting implant releasing the GnRH analog deslorelin (Ovuplant™) or with 1,500—2,500 IU hCG, or not. Follicle sizes were determined with ultrasonography at admission to the study (i.e. day of CIDR-B insertion), at intervals during treatment, at device removal and in 24 (to 48) hour intervals thereafter to determine the time for treatment to induce and accelerate ovulation and to ovulation, respectively. Pregnancies were determined by ultra-sonography between Days 14 to 18 after breeding, mostly 12 to 14 days after ovulation. Based on the size of the largest follicle at admission, mares were grouped into Classes with a ollicle diameter of 10 mm or less in Class I, and mares with follicles 11-20 mm, 21-30 mm and >30 mm in Classes II, III and IV, respectively. Overall, 80.2% of all mares responded to treatment with estrus and 80.7% ovulated. For mares in Classes I to IV, the rate of mares bred and becoming pregnant was 53.4% and 66.7%, 65.6% and 58.7%, 87.5% and 52.3%, and 75.0% and 52.0%, respectively. The overall pregnancy rate was 55.6% for the first breeding in response to treatment. Mares not assisted with Ovuplant or hCG were bred at a significantly lower rate (<0.0001) and the pregnancy rate was lower, 44.4% vs. 54.2% and 60.5%, respectively. Treatments with Ovuplant or hCG ensured ovulation rates of 96.0 and 84.9% versus 53.3% in unassisted mares overall. Follicle diameters increased significantly with CIDR-B in situ, and progressed after device removal to >30 mm within 4.0 days and to ovulation 5.3 days. Those mares in Class I responding to treatment (ca 60%) did not differ from Class II to IV mares in almost all the parameter evaluated. Significant differences were seen in the UK in response to treatment between years for the percentage of mares showing heat, ovulated, were bred and became pregnant.  相似文献   

14.
Between February 15 and May 17, 2011, a total of 88 broodmares (10 maiden, 10 barren, and 68 foaling) maintained on pasture in southeast Texas were examined three times weekly (Tuesday, Thursday, Saturday) by transrectal palpation and ultrasonography. On Tuesday or Thursday, mares in estrus with uterine edema, a relaxed cervix, and a dominant follicle ≥34 mm in diameter were alternately assigned to treatment with the following: group (1) 2,500-unit human chorionic gonadotropin (hCG), intravenous; group (2) 1.0-mg BioRelease Histrelin (Biorelease Technologies, Lexington, KY), intramuscular; or group (3) 0.5-mg BioRelease Histrelin, intramuscular. Ovulation was confirmed by ultrasonographic examination. The percentage of mares ovulating within 2 days appeared to be similar between maiden, barren, and foaling mares, so responses for all mares were totaled for analysis. A nonsignificant trend for higher ovulation rates within 2 days was noted for both dose rates of histrelin compared with hCG treatment (31/37, 84%; 34/37, 92%; and 33/36, 92% for groups 1-3, respectively) (P = .45). Ovulatory responses appeared to improve for both products as the season progressed, yet no differences were detected between response rates to histrelin or hCG for any month (P ≥ .50). The use of 1.0- or 0.5-mg BioRelease Histrelin was found to be at least equally effective as hCG treatment for inducing ovulation within 2 days of treatment throughout the breeding season.  相似文献   

15.
Deslorelin acetate (Ovuplant™, Fort Dodge), a GnRH agonist, is commonly used to induce ovulation in cycling mares. Although its efficacy in hastening ovulation has been previously reported, the effects of age of mare and month of administration on percent of mares responding and interval to ovulation have not been studied.Data was gathered from reproduction records of 376 mares receiving deslorelin acetate at the Equine Reproduction Laboratory, Colorado State University, from 1995 to 1999. Age of mare, date of administration, size of largest follicle at treatment, and interval to ovulation were recorded. Age of mare was categorized into five groups: 2–4, 5–9, 10–14, 15–19, and greater than or equal to 20 years. Date of administration was divided into four groups: March and April, May and June, July and August, and September and October.A higher (p < 0.05) percentage of mares aged 10–14 (98.5%) ovulated in response to deslorelin acetate than mares aged 2–4 or 5–9 (90.2% or 91.0%, respectively) or mares aged 15–19 or ≥ 20 (87.9% or 83.8%, respectively). Mares ≥ 20 had the lowest ovulation rate (83.8%). However, mares ≥ 20 that responded to deslorelin acetate had a shorter (p < 0.05) interval from treatment to ovulation (1.7 ± 0.1 days) than mares 2–4 and 5–9 years of age (1.9 ± 0.1 and 1.9 ± 0.0 days, respectively).Deslorelin acetate was more effective in inducing ovulation in the July and August (95.4%) (p < 0.01) and September and October (95.7%) (p = 0. 04) than in the March and April (81.1%). Mares treated in May through October also experienced shorter (p < 0.05) intervals to ovulation than mares treated in March and April.  相似文献   

16.
The objective of this study was to compare the efficacy of purified equine‐ and porcine‐FSH treatment regimes in mares in early vernal transition. Mares (n = 22) kept under ambient light were examined ultrasonographically per‐rectum, starting January 30th. They were assigned to one of two treatment groups using a sequential alternating treatment design when a follicle ≥ 25 mm was detected. In the eFSH group, mares were treated twice daily with equine‐FSH, and in the pFSH group mares were treated twice daily with porcine‐FSH; treatments were continued until follicle(s) ≥ 35 mm, and 24 h later hCG was administered. Oestrous mares were inseminated with fresh semen and examined for pregnancy on days 11–20 post‐ovulation. In the eFSH group, 11/11 (100%) mares developed follicle(s) ≥ 35 mm, 8/11 (73%) ovulated and 6/8 (75%) conceived. In the pFSH group, 5/11 (45%) developed follicle(s) ≥ 35 mm, 4/11 (36%) ovulated and 3/4 (75%) conceived. Treatment with eFSH resulted in a greater ovarian stimulation; higher number of pre‐ovulatory‐sized follicles, higher number of ovulations and higher number of embryos (p < 0.05). Following ovulation, serum progesterone concentrations were correlated with the number of CLs and supported early embryonic development; maternal recognition of pregnancy occurred in all pregnant mares. We concluded that eFSH can be used to effectively induce follicular growth and ovulation in vernal transitional mares; however, if bred, diagnosis and management of twins’ pregnancies would be required prior to day 16 because of the increased risk of multiple embryos per pregnancy. Conversely, the current pFSH treatment regime cannot be recommended.  相似文献   

17.
This study investigated the efficacy of two dosage regimens of a potent GnRH analogue (GnRHa), deslorelin acetate, in inducing ovulation in seasonally anestrous mares. Forty-five seasonally anestrous mares were randomly assigned according to follicular size to one of three treatment groups: control, increasing GnRHa dose, and constant GnRHa dose. Treatment began on February 28 and continued until ovulation or for a maximum of seven treatments. Mares were palpated every other day until a 35 mm follicle was detected, then every day until ovulation or regression of the follicle occurred. Blood samples were taken from five randomly chosen mares in each treatment group and analyzed for LH levels.Twenty percent of mares in both deslorelin treatment groups ovulated, while no control mares ovulated during the treatment period. There was no difference in the number of mares that ovulated between treatment groups. Four of the six mares that ovulated were in transitional anestrus at the initiation of treatment, while only two were in deep anestrus.Concentrations of LH were greater (p=0.0008) in both GnRH-treated groups than in the control mares. Concentrations of LH did not differ between the two GnRH-treated groups until day 12 of treatment, when mares treated with a constant dosage had higher (p=0.0358) levels of LH than those treated with an increasing dosage. It is possible that administration of larger amounts of the GnRH agonist lowered the sensitivity of the pituitary to stimulation by GnRH.Deslorelin acetate did stimulate follicular growth and ovulation in a limited number of anestrous mares. Further investigation into the potential of this short-term implant to shorten the onsent of the breeding season is recommended.  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.
Soon after Ovuplant™, the sustained-release implant containing the gonadotropin releasing hormone (GnRH) agonist deslorelin, was approved for commercial use in the United States for induction of ovulation in mares, anecdotal field observations were reported that some Ovuplant™—treated mares that did not become pregnant experienced a delayed return to estrus and prolonged inter-ovulatory interval. Although those observations have been subsequently confirmed, further data on how mares respond to Ovuplant™ compared to human chorionic gonadotropin (hCG) during the post-treatment period is needed. The objective of this study was to further evaluate the clinical use of Ovuplant™ by comparing the reproductive performance of commercial broodmares treated with hCG or Ovuplant™. This retrospective study was completed by examining the 1999 reproductive records of 106 mares treated with hCG during 134 estrous cycles and 117 mares treated with Ovuplant™ during 151 estrous cycles. There were no differences (P > 0.10) in follicle size at the time of treatment (39.4 ± 0.5 vs. 38.9 ± 0.5 mm), interval from treatment to ovulation (2.2 ± 0.1 vs. 2.2 ± 0.1 days), proportion of mares that failed to ovulate after treatment (3.0 vs. 4.6 %), or per-cycle pregnancy rate (47.7 vs. 51.4 %) between hCG-and Ovuplant™-treated mares, respectively. The interval from ovulation to return to estrus (25.8 ± 1.3 vs. 15.5 ± 0.6 days) and the inter-ovulatory interval (30.4 ± 1.5 vs. 20.8 ± 0.6 days) were longer (P<0.001) for Ovuplant™-compared to hCG-treated mares, and the proportion of non-pregnant mares that failed to return to estrus within 30 days after ovulation (31.4 vs. 1.5 %) was higher (P<0.001) for Ovuplant™-compared to hCG-treated mares, respectively. For Ovuplant™—treated mares, follicle size at the time of treatment tended (P<0.1) to be smaller for mares that failed to return to estrus within 30 days compared to mares that returned to estrus within 30 days (37.1 ± 1.1 vs. 40.1 ± 0.6 mm, respectively). Also, the average date of ovulation during the calendar year was later (P < 0.05) for Ovuplant™—treated mares that failed to return to estrus within 30 days compared to those that returned to estrus within 30 days (May 15 ± 4 vs. April 30 ± 4 days). The results of this study confirm previous reports that although the ovulatory response and fertility were not different for hCG- and Ovuplant™—treated mares, mares treated with Ovuplant™ that did not become pregnant had a significantly delayed return to estrus and prolonged inter-ovulatory interval. Based on recently published information, it appears this effect is due to Ovuplant™—induced down-regulation of the pituitary gland, which suppresses subsequent follicular growth and development. This study also demonstrated that follicle size and/or season may influence the probability that Ovuplant™—treated mares would experience a delayed return to estrus/ovulation; therefore, further work is needed to determine whether these or other factors are related to this specific outcome following Ovuplant™—treatment.  相似文献   

20.
The presence of anovulatory haemorrhagic follicles during the oestrous cycle of mares causes financial impacts, slowing conception and increasing the number of services per pregnancy. Non‐steroidal anti‐inflammatory drugs (NSAIDs) such as meloxicam and phenylbutazone are used in the treatment of several disorders in mares, and these drugs can impair the formation of prostaglandins (PGs) and consequently interfere with reproductive activity. This study aimed to evaluate the effects of treatment with NSAIDs on the development of pre‐ovulatory follicles in mares. In total, 11 mares were studied over three consecutive oestrous cycles, and gynaecological and ultrasound examinations were performed every 12 h. When 32‐mm‐diameter follicles were detected, 1 mg of deslorelin was administered to induce ovulation. The first cycle was used as a control, and the mares received only a dose of deslorelin. In the subsequent cycles, in addition to receiving the same dose of deslorelin, each mare was treated with NSAIDs. In the second cycle, 4.4 mg/kg of phenylbutazone was administered, and in the third cycle, 0.6 mg/kg of meloxicam was administered once a day until ovulation or the beginning of follicular haemorrhage. All of the mares ovulated between 36 and 48 h after the induction in the control cycle. In the meloxicam cycle, 10 mares (92%) did not ovulate, while in the phenylbutazone cycle, nine mares (83%) did not ovulate. In both treatments, intrafollicular hyperechoic spots indicative of haemorrhagic follicles were observed on ultrasound. Thus, our results suggested that treatment with meloxicam and phenylbutazone at therapeutic doses induced intrafollicular haemorrhage and luteinization of anovulatory follicles.  相似文献   

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