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1.
To ensure sufficient numbers of pregnant females, particularly at hotter times of the year, hormonal induction of gilt oestrus may be necessary. However, the gilt oestrus and ovulation responses to gonadotrophin treatment have often proven unpredictable. The objective of this study was to examine possible reasons for this unpredictability. Prepubertal gilts (approximately 150 days of age, n = 63) were assigned to one of three treatments: injection of 300 IU hCG (n = 15); pre-treatment with 100 mg FSH in polyvinylpyrrolidinone administered as 2 × 50 mg injections 24 h apart, followed by 600 IU eCG at 24 h after the second FSH injection (n = 23); or FSH pre-treatment as above followed by 300 IU hCG at 24 h after the second FSH injection (n = 25). To facilitate oestrus detection, gilts were exposed to a mature boar for 15 min daily for 7 days. Blood samples were obtained on the day of eCG or hCG injection and again 10 days later and gilt ovulation responses determined based on elevated progesterone concentrations. The oestrus responses by 7 days were 6.7%, 17.5% and 64.0% for gilts treated with hCG, FSH + eCG and FSH + hCG, respectively (p < 0.001). The oestrous gilt receiving hCG alone and one oestrous FSH + hCG gilt did not ovulate, all other oestrous gilts ovulated. A further two anoestrous FSH + eCG-treated gilts ovulated. These data suggest that FSH pre-treatment facilitated the development of ovarian follicles to the point where they became responsive to hCG, but had little effect on the response to eCG.  相似文献   

2.
To meet weekly breeding targets, it is occasionally necessary to inject exogenous gonadotrophins to induce oestrus in prepubertal gilts. However, the gilt oestrus response to equine chorionic gonadotrophin (eCG) either alone or in combination with human chorionic gonadotrophin (hCG) can be unpredictable. The objective of the present study was to examine possible reasons for this unpredictability. Prepubertal gilts (90 kg and 153 days of age, n = 109) received an injection of either 600 IU eCG or a combination of 400 IU eCG and 200 IU hCG (PG600), or were non-injected controls, and were then exposed to a mature boar for 15 min daily for 7 days for oestrus detection. At the time of injection, real-time ultrasound revealed that the gilt ovaries had primarily 1–2 mm follicles. Blood samples were obtained at time of hormone injection (day 0) and at days 3, 7 and 10 for assay of serum progesterone concentrations. The oestrus responses by 7 days were15.5%, 73.3% and 0%, for eCG, PG600, and control gilts, respectively (p < 0.001). The oestrus response improved (p < 0.05) with increasing body weight. Based on circulating progesterone levels, all oestrous gilts ovulated except for four of the PG600 gilts. Failure to express oestrus in PG600 gilts was not associated with a premature rise in progesterone.  相似文献   

3.
Objective To determine the efficacy and reliability of cabergoline and pregnant mare's serum gonadotrophin (PMSG) for induction of oestrus in bitches with primary or secondary anoestrus. Procedures We studied 39 healthy bitches of various breeds aged 2–6 years and in primary or secondary anoestrus: 20 bitches were administered 5 µg/kg/day cabergoline orally until day 2 after the onset of pro‐oestrus or for a maximum of 42 days, and 19 bitches were administered 20 IU/kg/day PMSG intramuscularly for 5 consecutive days, followed by an additional single injection of 25 IU/kg of human chorionic gonadotrophin on the fifth day. Results The rates of oestrus induction in the primary and secondary anoestrous bitches treated with cabergoline and PMSG were found to be similar. Pregnancy and whelping rates in the cabergoline group were statistically different from the rates in the PMSG group (P < 0.001). Conclusion Cabergoline is more effective and reliable for the induction of a fertile oestrus in bitches with primary or secondary anoestrous.  相似文献   

4.
The oestrus cycle in the domestic bitch, a monoestrous species, differs considerably from that of other veterinary domestic animals species. In the bitch the combined use of eCG and hCG is effective to induce oestrus predictably and safely (Stornelli et al., Theriogenology, 78, 2012 and 1056). Although several studies were done to describe the hormonal changes during the canine oestrus cycle, to our knowledge none was done to describe the hormonal changes during induced follicular growth after the administration of eCG. The aim of this work was to study prolactin (PRL), insulin‐like growth factor (IGF1) and androstenedione (ANDR) serum concentrations during follicular growth induced by a single dose of eCG administered to late anoestrous bitches. PRL and ANDR concentrations were lower before than after eCG TRT (before eCG vs pro‐oestrus, oestrus and dioestrus; 4.3 ± 1.8 ng/ml vs 6.5 ± 1.6 ng/ml, p < 0.05; 0.08 ± 0.2 ng/ml vs 0.42 ± 0.16 ng/ml, p < 0.05). Conversely, IGF1 concentrations were similar before and after eCG TRT (286.0 ng/ml ±32.2, p > 0.53). Additionally, PRL concentrations were similar before oestrus compared to during oestrus and dioestrus (6.9 ± 1.7 ng/ml, p > 0.19). Furthermore, IGF1 concentrations were higher before and during oestrus compared to first day of dioestrus (286.1 ± 29.8vs 200.4 ± 29.2 ng/ml, p < 0.01). On the contrary, ANDR concentrations were lower before and during oestrus compared to first day of diestrum (0.35 ± 0.17 ng/ml and 0.38 ± 0.15 vs 0.68 ± 0.17 ng/ml, p < 0.05). These results show that treatment with a single injection of 50 IU/kg of eCG in late anoestrous bitches successfully induced changes in follicular growth which were paralleled with changes in PRL, IGF1 and ANDR serum concentration similar to those occurring during a normally occurring oestrous cycle. In addition, our results suggest that IGF1 in the bitch could play an important role in ovarian folliculogenesis.  相似文献   

5.
In this study, ovarian morphologies and blood progesterone concentrations following oestrous induction in bitches were examined. Fifty‐three clinically healthy anoestrus bitches received cabergoline at a daily dose of 5 μg/kg of body weight per os for 21 days (group I) or subcutaneous equine chorionic gonadotropin at a dose of 20 IU/kg of body weight for five consecutive days with an additional 500 IU s.c. per bitch of human chorionic gonadotropin on the last day of treatment (group II). Twenty bitches that spontaneously displayed oestrous signs were left untreated and served as controls (group III). The induced oestrous rates and ovulation rates in groups I and II were 60.0% vs 64.3% and 86.7% vs 83.3%, respectively. Morphological assessments of the ovarian structures after ovariohysterectomy revealed an increase in the number of luteinized follicles and cysts in group II compared with the two other groups (p < 0.001). In contrast, the numbers of corpora lutea and follicles were similar in all groups. In accordance with the above‐mentioned alteration, the progesterone concentration in the gonadotropin group (II) was increased (p < 0.001) in the periovulatory period compared with the other two groups. During the entire sampling period, the progesterone profiles in the cabergoline (I) and control (III) groups were similar and typical of normally cycling bitches. In conclusion, gonadotropin treatment is associated with an increased progesterone level during the periovulatory period that probably originates from luteinized follicles, whereas cabergoline treatment induces cycles with both physiological progesterone concentrations and ovarian morphologies.  相似文献   

6.
Seventeen bitches (11 anoestrous, 4 prepubertal, 1 pregnant and 1 postpartum) were treated with pregnant mare serum gonadotrophin (110 iu/kg) at weekly intervals up to the occurrence of oestrus or a maximum of 3 treatments. Oestrus was induced in 8/11 anoestrous bitches only. The between bitch ovarian response was very variable. Ovulation occurred in 7/8 PMSG induced oestrous bitches. The 3 oestrous bitches treated with human chorionic gonadotrophin (500 iu) at the start of oestrus had a better ovulatory response than those treated with PMSG alone.  相似文献   

7.
Gilt oestrus and ovulation responses to injection of a combination of equine chorionic gonadotrophin (eCG) and human chorionic gonadotrophin (hCG) (PG600) can be unpredictable, possibly reflecting inadequate circulating LH activity. The objective of this study was to determine the effect of PG600 followed by supplemental hCG on gilt ovarian responses. In experiment 1, 212 Hypor gilts (160 day of age) housed on two farms in Spain received intramuscular (i.m.) injections of PG600 (n = 47), or PG600 with an additional 200 IU hCG injected either concurrently (hCG‐0; n = 39), or at 24 h (hCG‐24; n = 41) or 48 h (hCG‐48; n = 45) after PG600. A further 40 gilts served as non‐injected controls. Ovulation responses were determined on the basis of initial blood progesterone concentrations being <1 ng/ml and achieving >5 ng / ml 10 d after the PG600 injection. The incidence of ovulating gilts having progesterone concentrations >30 ng/ml were recorded. During the study period, 10% of control gilts ovulated whereas 85–100% of hormone‐treated gilts ovulated. There were no significant differences among hormone groups for proportions of gilts ovulating. The proportions of gilts having circulating progesterone concentrations >30 ng/ml were increased (p ≤ 0.02) in all hCG treated groups compared with the PG600 group. In experiment 2, a total of 76 Hypor gilts at either 150 or 200 days of age were injected with PG600 (n = 18), 400 IU eCG followed by 200 IU hCG 24 h later (n = 20), PG600 followed by 100 IU hCG 24 h later (n = 17), or 400 IU eCG followed by 300 IU hCG 24 h later (n = 21). Blood samples were obtained 10 days later for progesterone assay. There were no effects of treatment or age on incidence of ovulation, but fewer 150‐day‐old gilts treated with PG600 or 400 IU eCG followed by 200 IU hCG had progesterone concentrations >30 ng / ml. We conclude that hCG treatment subsequent to PG600 treatment will generate a higher circulating progesterone concentration, although the effect is not evident in older, presumably peripubertal, gilts. The mechanism involved and implications for fertility remain to be determined.  相似文献   

8.
In four Kenyan pig breeding units the pregnancy diagnosis of sows has been carried out in two groups: Group 1 (n = 1911): the sows were transrectaly pregnancy tested between Days 17-22 post-mating by ultrasound. Sows testing non-pregnant immediately received one dose of 400 IU pregnant mare serum gonadotropin (PMSG) (equine chorion gonadotropin, eCG) and 200 IU human chorion gonadotropin (hCG). On showing signs of oestrous, the animals were subsequently artificially inseminated (AI). Group 2 (n = 1923): sows were pregnancy tested by serum progesterone (P4)-based enzyme-linked immunosorbent assay (ELISA) on Day 17 post-breeding. P4 concentrations were categorized as positive (> 5 ng/ml) or negative (< 5 ng/ml). Sows testing nonpregnant immediately received one dose of 400 IU PMSG and 200 IU hCG by injection, and were subsequently artificially inseminated. The following parameters were evaluated: sows diagnosed non-pregnant, days from first post-weaning insemination until the sows were inseminated at their first return to oestrus; farrowing rate and total piglets born and number of live-born piglets in litters. The percentage of sows diagnosed non-pregnant in the two groups, as well as the totals of born piglets and of live-born piglets in litters did not differ significantly between the two groups. The number of days from the first post-weaning mating until the sows were artificially inseminated at their first return to oestrus and the administration of eCG and hCG was shorter (P < 0.01) and farrowing rate was higher (P< 0.01) in the ELISA-tested sows.  相似文献   

9.
Twenty-eight bitches with unknown reproductive histories were injected intravenously with either human chorionic gonadotrophin (hCG) or equine chorionic gonadotrophin (eCG) (pregnant mare's serum gonadotrophin) and their oestradiol responses were measured at the time of the injection and 90 minutes later. They were at various stages of the oestrous cycle as determined by histology and a progesterone assay for luteal function. Twenty-six of them were considered to be entire because they showed either an increase in plasma oestradiol over preinjection values or steady high values. The ovaries were removed from 25 of these animals and the other probably had a remnant of ovary because it came into oestrus some weeks later. In two remaining bitches no oestradiol could be detected either before or after the injection of gonadotrophin and they were predicted to have been neutered, which was confirmed at laparotomy. In the entire bitches, the highest plasma oestradiol concentration was measured during metoestrus and the lowest during anoestrus.  相似文献   

10.
The aim of this study was to evaluate the reproductive performance of three parities of gilts treated or not treated with gonadotropin to induce puberty. Sixty gilts received 600 IU of equine chorionic gonadotropin (eCG) followed by 2.5 mg of porcine luteinizing hormone (LH) 72 h later. Fifty‐nine other gilts were exposed only to a mature boar for 15 min twice daily. Artificial insemination (AI) was performed at 0, 12 and 24 h after the detection of oestrus, and gestation was confirmed by ultrasound after 35 days. Sows were inseminated at the first post‐weaning oestrus. The total numbers of piglets born, piglets born alive, stillborn, mummified foetuses, as well as pregnancy and farrowing rates were evaluated for each of the three parities. Culling rates, farrowing intervals and weaning‐to‐oestrous intervals (WEI) were also analysed. Mean age at puberty and oestrous manifestation were not significantly different between treatments (p = 0.0639; 179.20 ± 17.52 compared with 173.96 ± 16.94, 91.66% compared with 94.92%) across the experimental period. However, females that underwent puberty induction showed modest increases both in the number of total pigs born and in the number of piglets born alive. In conclusion, puberty induction through exogenous gonadotropin administration in field conditions did not induce a more concentrated first oestrous manifestation, but trended to a modest increase in the number of pigs born alive in the first parity and a reduced culling rate during the first gestation.  相似文献   

11.
This study sought to improve the reproductive performance of anoestrous high-producing dairy cows by including equine chorionic gonadotrophin (eCG) after progesterone-releasing intravaginal device (PRID) removal. In Experiment I, 806 cows at 51-57 days post-partum were randomly assigned to a PRID (treated with PRID), PRID-500 (treated with PRID plus 500 IU of eCG) or PRID-750 (treated with PRID plus 750 IU of eCG) group. In Experiment II, 422 cows showing a long anoestrus period (animals with no oestrus signs nor luteal tissue 35 days before treatment) were randomly assigned to the PRID, PRID-500 or PRID-750 groups. The dependent variables considered in binary logistic regression analyses for both experiments were the rates of oestrus, ovulation and conception after treatment, the cumulative conception rate on Day 120 post-partum and pregnancy loss. In Experiment I, interaction between treatment and season showed a significant effect on the oestrous response. Thus, during the warm season, PRID group cows were 8.9 times more likely to express oestrus than the remaining cows. Moreover, inseminated cows with two or more corpora lutea 8-14 days after treatment were more likely to become pregnant (by a factor of 2.4) than cows with a single corpus luteum. Finally, cows without luteal structures treated with PRID were 0.4 less likely to be pregnant on Day 120 post-partum, compared with the remaining cows. In Experiment II, cows in the PRID group treated during the warm or cool season were less likely to exhibit oestrus (by a factor of 0.06 or 0.2, respectively) or ovulate (by a factor of 0.004 or 0.14, respectively) than the remaining cows. In conclusion, in anoestrous cows in both experiments, the addition of eCG to the use of an intravaginal progesterone device to induce oestrus was beneficial. The recommended dose of eCG is 500 IU.  相似文献   

12.
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   

13.
The effects of passive immunoneutralization of endogenous inhibin on ovulation rate in immature rats were investigated. Efficiency of superovulation on production of fertilized oocytes was compared between the inhibin antiserum (inhibin-AS) and equine chorionic gonadotropin (eCG) protocols. Immature female Wistar strain rats were superovulated with a single injection of 100-200 microl inhibin-AS, with and without an injection of human chorionic gonadotropin (hCG). A total of 77.8% of the 26-30-day-old rats treated with a single injection of 100-200 microl inhibin-AS ovulated 72 h after treatment, while rats given normal goat serum (NGS; 200 microl) did not ovulate. At 28 days of age, all of the inhibin-AS treated rats ovulated when additional hCG treatment was given, whereas the number of ovulated oocytes was not affected. The number of ovulated oocytes in the inhibin-AS-hCG treated groups was significantly higher than that of the NGS-hCG treated group. In addition, plasma concentrations of FSH in the inhibin-AS-hCG treated group significantly increased compared with the NGS treated group. While the percentage of mated rats in the 200 microl inhibin-AS-hCG treated group was significantly lower than that of the 15 IU eCG-hCG treated group, the fertilization rate was comparable between the two groups. The number of fertilized oocytes in the 200 microl inhibin-AS-hCG treated group was significantly higher in comparison with the 15 IU eCG-hCG treated group. These results suggest that immunoneutralization of endogenous inhibin could be a reliable method for induction of superovulation to collect a large number of normally fertilized oocytes in immature rats.  相似文献   

14.
Plasma steroid profiles following follicle-stimulating hormone (FSH) or equine chorionic gonadotropin (eCG) injection were studied in chronically gonadotropin releasing hormone agonist (GnRH-A)-treated cows. Follicular development and irINH secretion were stimulated by FSH or eCG injection. The plasma concentrations of estradiol-17 beta (E(2)) and testosterone (T) were markedly increased following eCG injection. However, significant increases of the plasma E(2) and T concentrations were not detected in FSH-treated cows. Ovulation of developed follicles were depended on the hCG injection in both groups. These results show: 1) Follicular response to an exogenous gonadotropin is still remained, 2) Ovulation of developed follicles is induced by hCG injection and 3) FSH and eCG cause disparate plasma steroid profiles, under the influence of repeated GnRH-A treatment.  相似文献   

15.
Ovarian sensitivity to exogenous gonadotropin stimulation (equine chorionic gonadotropin [eCG] and human chorionic gonadotropin [hCG]) following pre-treatment with a progestin (levonorgestrel) versus GnRH antagonist (antide) was studied in cats known to be induced versus spontaneous ovulators. Queens were assigned to one of three treatments: (1) levonorgestrel implants+eCG/hCG (n=7 cats); (2) antide injections+eCG/hCG (n=7) or (3) eCG/hCG alone (control; n=7). Hormonal metabolites were assessed in fecal samples collected daily for 60 days before and during the 37 days inhibitory pre-treatment and for more than 60 days after eCG/hCG. Fecal metabolites of estradiol and progesterone were measured by radioimmunoassay. Females that maintained baseline progesterone were considered induced ovulators, whereas cats that exhibited a luteal phase before inhibition treatment were classified as spontaneous ovulators. Based on fecal hormone profiles, levonorgestrel thoroughly inhibited ovarian activity, whereas antide synchronized follicular phases but did not induce complete ovarian down-regulation. Both treatments prevented ovulation in spontaneous ovulators, but neither caused regression of existing corpora lutea (CL). Levonorgestrel, but not antide, pre-treatment resulted in a quiescent ovary at the time of eCG injection, yet endocrine responses to eCG/hCG were not different among treatments. Interestingly, spontaneously ovulating females exhibited a prolonged estradiol response to gonadotropin stimulation compared to induced ovulators, and this prolonged estradiol surge was replicated by levonorgestrel pre-treatment. Thus, the progestin levonorgestrel effectively suppresses follicular and luteal activity in the cat, resulting in a more consistent response to gonadotropin stimulation, even in females prone to spontaneous ovulation.  相似文献   

16.
Seasonally, bred wild mice provide a unique bioresource, with high genetic diversity that differs from wild‐derived mice and laboratory mice. This study aimed to establish an alternative superovulation method using wild large Japanese field mice (Apodemus speciosus) as the model species. Specifically, we investigated how the application of inhibin antiserum and equine chorionic gonadotropin (IASe) during both the reproductive and non‐reproductive seasons impact the ovulation rate and competence of embryo development after in vitro fertilization (IVF) with fresh and cryopreserved sperm. When the wild mice were superovulated by injecting eCG followed by human chorionic gonadotropin (hCG), few oocytes were collected during the reproductive and non‐reproductive seasons. In comparison, the number of ovulated oocytes was dramatically enhanced by the administration of IASe, followed by isolation of ovulated oocytes 24 hr after 30 IU hCG administration. The IVF oocytes that were in vitro cultured (IVC) with medium containing serum further developed to the 2‐ and/or 4‐cell stage using both fresh and frozen‐thawed sperm. In conclusion, we successfully established an alternative protocol for collecting ovulated oocytes from wild large Japanese field mice by administering IASe and hCG during both the reproductive and non‐reproductive seasons. This study is the first to develop IVF–IVC wild large Japanese field mice beyond the 2‐ and/or 4‐cell stage in vitro using fresh and cryopreserved sperm. This approach could be used in other species of wild or endangered mice to reduce the number of animals used for experiments, or in maintaining stocks of germ cells or embryos.  相似文献   

17.
The efficacy of eight combinations of fluorogestone acetate (FGA, 20 or 40 mg as intravaginal device during 11 days), equine chorionic gonadotropin (eCG, 300 or 500 UI injected 48 hr before FGA removal) and prostaglandin F2α (cloprostenol, 0 or 50 μg injected 48 hr before FGA removal) aiming at induction and synchronization of oestrus and ovulation was evaluated during the anoestrus season in spring and during the breeding season in autumn in adult Beni Arouss goats. Oestrous behaviour was recorded between 12 and 60 hr after FGA removal. Blood samplings allowing to assess onset of the pre‐ovulatory LH surge and increase of progesterone as sign of an active corpus luteum were performed, respectively, between 20 and 60 hr and 3, 5, 8 and 15 days after FGA removal. No season‐related differences (spring vs. autumn) were observed for oestrous response (95% vs. 93%), pre‐ovulatory LH surge (94% vs. 84%) and luteal response after 3–8 and 11–15 days post‐treatment (respectively 92% vs. 66% and 92% vs. 98%). The onset of oestrus (21 [13–53] vs. 32 [12–54] hr) and LH surge (26 [20–60] vs. 38 [22–60] hr) occurred significantly later in autumn. FGA (40 vs. 20 mg) in autumn significantly delayed the onset of oestrus (36 [16–54] vs. 23 [12–47] hr) and LH surge (44 [26–58] vs. 33 [22–60] hr). Significant treatment‐related differences were recorded for onset of LH surge (earliest for 20 mg FGA, 300 IU eCG, 50 μg PGF2α) and onset of luteal phase (latest for 40 mg FGA, 300 IU eCG, 50 μg PGF2α). In conclusion, the hormone combinations tested appeared equally effective in terms of oestrous and ovulation rates. Season has influenced significantly the onset of oestrus and LH surge, and the high dose regimen of FGA delayed the ovarian response in autumn.  相似文献   

18.
The capability of pregnant mare serum (PMS) and human chorionic gonadotropin (HCG) to induce estrus and ovulation was tested in mature, anestrous bitches. The PMS was given for 10 consecutive days in 1 of 3 regimens: 500 IU/day (experiment 1), 250 IU/day (experiment 2), or 20 IU/kg/day (experiment 3). The HCG was given as a single 500-IU dose on experimental day 10. Controls were given saline solution. Vaginal smears were collected on days 1, 3, 5, 7, 9, and 12 by jugular venipuncture, and the plasma was assayed for progesterone concentration by radioimmunoassay. On day 13, the bitches were euthanatized, ova were flushed from the uterine tubes (oviducts), and the ovaries were collected and prepared for microscopic examination. Fourteen of 25 bitches treated with PMS and HCG showed estrus and ovulated. Proestrus (vaginal bleeding) commenced between experimental days 7 and 10. Estrus commenced on day 9 or 10. Progesterone increased from approximately 1 ng/ml on day 1 to more than 6 ng/ml on day 12. Numbers of ovulation sites on both ovaries were 4.7 +/- 1.1 and 4.6 +/- 0.5 (mean +/- SEM) in those given the daily doses of 500 and 250 IU of PMS and 9.8 +/- 1.5 in experiment 3 bitches. Eleven hormone-treated dogs and 7 saline-treated dogs did not show any detectable response. Neither cystic nor unovulated, luteinized follicles appeared on the ovaries.  相似文献   

19.
We aimed to define whether embryo collection carried out after pseudopregnancy was of similar outcome and quality as after artificial abortion. To induce pseudopregnancy, 30 gilts or sows were given 20 mg intramuscular estradiol dipropionate (EDP) 10–11 days after the onset of estrus. Ten additional pigs were inseminated artificially at natural estrus as a control group. Prostaglandin F2α (PGF2α) was administered twice with a 24 hr interval beginning 15, 20, or 25 days after EDP‐treatment (n = 10 per group) or between 23 and 39 days after artificial insemination in control pigs. Following this, all pigs were given 1,000 IU equine chorionic gonadotropin and 500 IU human chorionic gonadotropin (hCG) and then inseminated. Embryos were recovered 6 or 7 days after hCG treatment and outcome was recorded. There was no significant difference in the number of normal embryos collected from the pigs with PGF2α initiated at different time points or from the control group. Embryonic developmental stages 7 days after hCG treatment also did not differ among groups. These results indicate that the use of EDP to induce pseudopregnancy, followed by PGF2α administration to synchronize estrus for subsequent embryo harvest, is a suitable alternative to the artificial abortion method.  相似文献   

20.
We tested FSHp, eCG and FSHp + eCG to establish ovum pick-up (OPU) and in vitro maturation method in spotted paca. Eight healthy adult females were subjected to each of four treatments to stimulate ovarian follicular growth. All females were subjected to a hormonal protocol using a single dose of 45 mg of injectable progesterone and single intramuscular injection of 0.075 mg d-cloprostenol on day 6. Ovarian stimulation was carried out as follows: in Group TFE (FSHp and eCG), animals were treated with a single dose of 80 mg of FSHp and 200 IU of eCG intramuscularly on day 6 after the application of progesterone; in Group TF (FSHp), they were treated with a single dose of 80 mg of FSHp intramuscularly on day 6 after application of progesterone; in Group treatment eCG, they were treated with 200 IU of eCG intramuscularly on day 6 after application of progesterone; and in Group TC (saline solution), 1 ml of saline solution was administered to control does. The OPU was performed between 22 and 26 hr after gonadotropin treatments. All recovered oocytes were placed into maturation media and incubated for 24 hr. There were no differences among the mean number of observed follicles, aspirated follicles and oocytes recovered per treatment. Oocyte maturation rates did not differ among groups, except, TF and treatment eCG oocytes had greater maturation rates than TC oocytes. In this study, gonadotropin administration failed to superovulate treated does and increase oocyte retrieval efficiency. Despite the feasibility of the procedure, further studies are needed to develop and refine hormonal protocols for oocyte recovery and in vitro maturation in this species.  相似文献   

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