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PubMed1999

Repeatability and heritability of response to superovulation in Holstein cows.

The objective of this study was to estimate the relative effects of genetic and phenotypic factors on the efficacy and efficiency of superovulation for Holstein-Friesian cows reared in Brazil. A database, established by the Associacao Brasileira de Criadores de Bovinos da Raca Holandesa, consisting of a total of 5387 superovulations of 2941 cows distributed over 473 herds and sired by 690 bulls was used for the analysis. The records were analyzed by MTDFREML (Multiple Trait Derivative-Free Restricted Maximum Likelihood), using a repeatability animal model. The fixed effects included in the model were contemporaneous group (veterinarian, herd, year and season of the superovulation); number of semen doses; cow age; and superovulation order. The estimated repeatability of the number of the transferable embryos was low (0.13), and the estimated heritability was 0.03. These results indicate that environmental factors play a critical role in the response of a cow to a superovulation treatment. There is little evidence that future responses to superovulation by individual females can be predicted by previous treatment(s) or that superovulation response is an heritable trait.

Aging↗

PubMed2000

Effect of nutrition and superovulation on oocyte morphology, follicular fluid composition and systemic hormone concentrations in ewes.

The objective was to determine the effect of dietary intake on follicle and oocyte morphology in unstimulated and superovulated ewes. Fifty-four ewes were fed grass meal at 0.5, 1.0 or 2.0 times maintenance energy requirements (M) for 32 days. Oestrous cycles were synchronized using progestagen pessaries and either unstimulated or superovulated with 200 mg pig FSH. The ewes were killed and ovaries were collected either 36 or 12 h before the anticipated LH surge. Serum progesterone concentrations in ewes on day 10 after withdrawal of the pessary were lower in ewes fed 2.0M than in ewes fed 0.5M or 1.0M (P < 0.05). LH pulse frequency tended to be higher in ewes fed 2M than 1M (1.0 +/- 0.3 versus 0.3 +/- 0.2 pulses per 8 h) on day 6 after removal of the pessary but the effect was not significant. In unstimulated ewes, more follicles (>/= 3 mm) were observed when the animals were killed in ewes fed 2.0M (3.5 +/- 0.3) than in ewes fed 0.5M (2.4 +/- 0.3) or 1.0M (2.4 +/- 0.5; P < 0. 05). Fewer follicles were observed in superovulated ewes on 0.5M (7. 5 +/- 1.2) than in ewes on 1.0M (12.0 +/- 0.5) or 2.0M (12.3 +/- 1. 4; P < 0.05). Follicular fluid progesterone concentrations were higher in ewes fed 0.5M compared with those fed 1M or 2M (P < 0.05). Insulin-like growth factor (IGF)-I concentrations were higher in follicular fluid from ewes on 1M compared with either those on 0.5M or 2M (P < 0.05), whereas IGF-II concentrations were lower in follicular fluid from ewes on 2M compared with those on 1M or 0.5M (P < 0.05). Superovulation increased follicular fluid progesterone, oestradiol, IGF-I and IGF-II concentrations (P < 0.01). Concentrations of the 34, 22 and 20 kDa IGF binding proteins were lower in follicles from superovulated ewes compared with unstimulated ewes (P < 0.05). Oocytes from superovulated ewes showed abnormalities such as premature activation of cumulus expansion and vacuolation of the nucleolus and increased frequency of detachment of interchromatin-like granules from the nucleolar remnant. Collectively, these results indicate that both high and low dietary intakes can alter systemic and follicular fluid hormone concentrations. Relative to dietary effects, the effects of superovulation were greater and involved substantial increases in follicular fluid hormone concentrations and abnormal oocyte morphology.

Animal Nutritional Physiological Phenomena↗

PubMed1995

Follicular development and reproductive endocrinology during and after superovulation in heifers and mature cows displaying contrasting superovulatory responses.

To understand the causes for poor response to superovulation in mature cows of high genetic potential, endocrine and follicular events during and after superovulation were compared in heifers (<2 yr old) yielding large numbers of embryos and cows (9 to 13 yr old) known to be poor embryo donors. Follicular development was monitored by daily ultrasonography. Blood samples were taken 2 to 3 times a day for the measurements of P4, E2, FSH and LH by RIA. Intensive blood collections at 15-min intervals for 6 h were also performed during preovulatory and luteal phases. The number of embryos produced in the heifers (15.2 +/- 2; mean +/- SEM) and the cows (0.6 +/- 0.4), was similar to the number of ovulatory follicles derived from ultrasonographic observations in the heifers (16.2 +/- 3.7), but not in the cows (7.8 +/- 2.8). Contrary to that observations in heifers, there was no increase in the number of 4- to 5-mm follicles in cows during superovulation. The number of larger follicles (>5 mm) increased during superovulation in both cattle groups, but it was significantly lower in cows than in heifers. During superovulation, the maximal E2 concentration was greater (P < 0.0001) in heifers than in cows. One cow showed delayed luteolysis during superovulation, while another had abnormally high FSH (>10 ng/ml) and LH (>3 ng/ml) concentrations following superovulation. All the cows had a postovulatory FSH rise which was not detected in the heifers. The results showed that attempts to improve superovulatory response in mature genetically valuable cows are hampered by a number of reproductive disorders that are not predictable from the study of the unstimulated cycle.

Journal Article↗

PubMed1992

Superovulation with human menopausal gonadotropins in the treatment of infertility associated with minimal or mild endometriosis: a controlled randomized study.

OBJECTIVE: To determine the efficacy of superovulation with buserelin acetate, human menopausal gonadotropins (hMG), and human chorionic gonadotropin (hCG) in the treatment of infertility associated with minimal or mild endometriosis. DESIGN: Prospective, randomized, controlled study. SUBJECTS: Forty-nine infertile women with a laparoscopic diagnosis of endometriosis stage I (n = 29) or II (n = 20) according to the revised American Fertility Society classification, randomly assigned to three superovulation cycles (n = 24) or 6 months' expectant management (n = 25). MAIN OUTCOME MEASURES: Cycle fecundity rates and cumulative pregnancy rates (CPR) in the two groups. RESULTS: Nine pregnancies were obtained in the superovulation-treated patients and six in the nontreated ones. The cycle fecundity rates and CPR were 0.15% and 37.4% after three superovulation cycles and 0.045% and 24% after 6 months of expectant management (P less than 0.05 and P = not significant, respectively). The women who did not achieve a pregnancy after three cycles of superovulation were followed for a total of 50 months during which no therapy was given. One pregnancy started in this period (cycle fecundity rate = 0.020). One spontaneous abortion occurred in each group. Three treated patients had multiple pregnancies, and four had ovarian hyperstimulation syndrome. CONCLUSION: Superovulation seems to be associated with a better cycle fecundity rate but not a better CPR than expectant management in infertile women with endometriosis stages I and II. The efficacy and side effects of this therapeutic approach should be evaluated in larger series.

Adult↗

PubMed1993

The prognostic value of serum concentrations of progesterone, estradiol, and luteinizing hormone during superovulation with and without adjunctive leuprolide therapy.

OBJECTIVE: To determine the predictive value of preovulatory serum concentrations of P, E2, and LH for pregnancy achieved with IUI after superovulation with and without adjunctive leuprolide acetate (LA) therapy. DESIGN: Randomized, crossover study of superovulation with and without LA therapy. SETTING: Infertility clinic. PATIENTS: Subfertile patients referred for superovulation and IUI. MAIN OUTCOME MEASURES: Preovulatory serum concentrations of P, E2, and LH on the day of hCG administration; pregnancy. RESULTS: Preovulatory serum concentrations of P, E2, and LH had equivalent predictive value for pregnancy during cycles stimulated without LA therapy. No single parameter was particularly useful in clinical decision making. Threshold P concentrations proposed in other studies as useful in predicting pregnancy did not correlate with cycle fecundity. The predictive value of preovulatory concentrations of P during superovulation with adjunctive LA therapy was significantly worse than P concentrations during superovulation without LA therapy. CONCLUSIONS: Preovulatory serum P, E2, and LH concentrations in superovulation and IUI are not helpful in determining prognosis for pregnancy. The relative utility of predictive parameters may vary for different treatment regimens.

Chorionic Gonadotropin↗

PubMed1996

The efficacy of immunotherapy in patients who underwent superovulation with intrauterine insemination.

OBJECTIVE: To determine if the immunotherapy with corticosteroids would improve pregnancy rate in infertile patients with ovulatory factor and patients with unexplained infertility who undergo superovulation with IUI. DESIGN: Prospective, controlled study. SETTING: Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, University of Ulsan, Seoul, Korea. PATIENTS: Nine-one infertile patients with ovulatory factors and 78 patients with unexplained infertility who underwent superovulation with IUI. RESULTS: The prevalence of autoantibodies (antinuclear antibody, lupus anticoagulant, anticardiolipin antibody, antidouble-stranded DNA antibody) was elevated significantly in patients with unexplained infertility compared with patients with ovulatory infertility (20.5% versus 3.3%). Forty-five patients with ovulatory factor underwent 72 cycles of superovulation with IUI, receiving corticosteroids. Thirty-eight patients with unexplained infertility underwent 75 cycles of superovulation with IUI, receiving corticosteroids. Forty-six patients with ovulatory factor who underwent 66 cycles of superovulation with IUI and 40 patients with unexplained infertility who underwent 75 cycles of superovulation with IUI served as controls, not receiving corticosteroids. In patients with ovulatory factor, there were no significant differences between the corticosteroid treatment group and control group in clinical pregnancy rate (38.9% versus 33.3%) or in spontaneous abortion rate (14.3% versus 13.6%). In patients with unexplained infertility, there was a significantly higher clinical pregnancy rate per cycle in the corticosteroid treatment group, with 45.3% (34/75) compared with 29.3% (22/75) in the control group but no difference between the corticosteroid treatment and control groups in spontaneous abortion rate (17.6% versus 13.6%). There were no side effects due to the use of corticosteroids.

Adrenal Cortex Hormones↗

PubMed1978

Cholesteryl ester depletion from the ovaries of superovulated female rats fed a normal or essential fatty acid deficient diet.

The cholesteryl ester content of the ovaries was determined in rats diets containing corn oil or hydrogenated coconut oil (essential fatty acid (EFA) deficient) and subjected to superovulation by injection of luteinizing hormone and follicle-stimulating hormone. Superovulation increased ovarian weight; the effect was greater in animals fed corn oil. Superovulation significantly decreased total ovarian cholesteryl ester concentration in animals fed corn oil, with disproportionately large decreases occurring in the esters of 20:1, 20:2, 22:5w6, and 22:6w3. Significant decreases were observed in these esters when the data were expressed on a unit mass of tissue basis or in relation to total ovarian mass. In superovulated, EFA-deficient rats, esters of 18:1, 20:1, 22:5w6, and 22:6w3 were significantly lower per unit mass of tissue but this was due, in all cases except that of 22:6w3, to the increased mass of ovarian tissue; there was no decrease in total esters per ovary weight during superovulation of deficient rats. The pattern and degree of selective changes in ovarian cholesteryl esters during superovulation were different from those previously reported for adrenal esters of stressed rats.

Animals↗

PubMed2001

Superovulation, fertilization and in vitro embryo development in mice after administration of an inhibin-neutralizing antiserum.

The present study was conducted to investigate the effect of immunoneutralization against endogenous inhibin on oocyte and embryo production in adult and immature mice. At 12:00 h on day 2 of oestrus (day 1 of dioestrus), a single i.p. injection of inhibin antiserum (50, 100, 200 or 400 microl per animal) or equine chorionic gonadotrophin (eCG; 10 or 20 iu per animal) or control goat serum (100 microl per animal) was administered to adult female mice. After 48 h, the mice in each of the three groups were given a single i.p. injection of hCG (10 iu per animal). At 42 h after hCG injection, ova were collected from oviducts and cultured in KSOM solution. Treatments with both inhibin antiserum-hCG and eCG-hCG induced superovulation in all the animals tested. The number of oocytes in animals treated with inhibin antiserum was significantly higher (P < 0.05) compared with the control group, and the number of oocytes ovulated in animals treated with 200 or 400 ml inhibin antiserum was significantly (P < 0.05) higher than that in animals treated with 10 or 20 iu eCG. The superovulated oocytes that were fertilized normally in vivo were able to form blastocysts in vitro. The rate of blastocyst development for animals treated with 50-200 ml inhibin antiserum was significantly (P < 0.05) higher than that of the eCG-treated animals. Irrespective of the day of the oestrous cycle, 200 microl inhibin antiserum administered at 12:00 h on each of 4 days induced superovulation in all the animals tested. The rates of oocyte and embryo production by these animals were significantly (P < 0.05) higher than in the control groups. Furthermore, administration of inhibin antiserum at doses of 50, 100, 200 or 400 ml produced similar results in 26-day-old immature mice. These results indicate that passive immunoneutralization of endogenous inhibin alpha-subunit induces superovulation in immature and adult mice. The superovulated oocytes obtained by administration of inhibin antiserum have normal embryonic developmental competence. Thus, it is concluded that this inhibin antiserum method is a new practical alternative for induction of superovulation in mice instead of the more commonly used eCG-hCG protocol.

Animals↗

PubMed1991

FSH injections and intrauterine insemination in protocols for superovulation of ewes.

In Exp. 1, five injections of crude FSH (20 mg total), starting 36 h before removal of progestin pessaries or injection of prostaglandin F2 alpha (PGF2 alpha), were found to be as effective for superovulation of ewes as seven injections starting 72 h before removal of pessaries. Seven injections caused superovulation (more than three ovulations) in 13 of 15 ewes with an average (all ewes) of 12 +/- 2.3 ovulations. Five injections caused superovulation in 17 of 19 ewes with an average of 11.5 +/- 1.6 ovulations after pessary-regulated estrus in 12 of 16 ewes with an average of 12.4 +/- 2.2 ovulations after PGF2 alpha injection. In Exp. 2, intrauterine artificial insemination (IUAI) of naturally mated ewes provided ovum fertilization rates of 75.3% with an embryo recovery rate of 39.4%, whereas mating alone (MATED) provided fertilization rates of 64.2% with an embryo recovery rate of 72.1%. However, subsequent replications of the MATED protocol (MATED2) resulted in a low fertilization rate (34.2%). In Exp. 3, surgical IUAI at 22 h after removal of pessaries resulted in a low rate of superovulation (5 of 12 ewes), presumably as the result of pentobarbital anesthesia. Conducting IUAI at 46 h after removal of pessaries resulted in a high rate of superovulation (14 of 16 ewes) but a low embryo recovery rate (30.7%). In two subsequent trials, IUAI at 40 h after removal of pessaries resulted in most ewes superovulating (33 of 35 in April/May and 16 of 17 in September) with acceptable embryo recovery (65.2% and 71.3%) and high fertilization rates (82.8% and 96.4%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1987

[Superovulation and uterine lavage in relation to subsequent conception in donor cows].

On the Slusovice co-operative farm, embryo transfer has been practised since 1984 as a method of controlled reproduction of the heifer and cow herd. The effect of superovulation, embryo recovery and administration of 500 micrograms Oestrophan Spofa upon the donors' conception rate and upon their resuming a new reproduction cycle was studied on this farm. The effect of superovulation, induced by FSH-P (Folicotropin, Spofa), was evaluated in 162 cows, out of which 121 (74.69%) got in calf after three inseminations. Fifty-nine (48.76%) of the pregnant cows got in calf after the first insemination, 38 (31.40%) after the second insemination, and 24 (19.83%) after the third insemination. Having been subjected to embryo collection and luteolysis, the donors conceived within 67.6 days, on an average, and the animals superovulated within 60 days post partum conceived within 59.11 days. The average SP of the superovulated animals was about 148 days but in the donors from which the embryos had been recovered within 60 postpartal days the SP did not exceed 110 days. Hence the earlier postpartal superovulation of cycling cows speeds up the resumption of reproduction in the donors and increases the numbers of recovered embryos. Repeated superovulation had no influence on the fertility of the cows but adequately prolonged the service period.

Animals↗

PubMed1996

Superovulation can reduce the developmental competence of bovine embryos.

This study was done to determine if different superovulatory regimens could have an effect on the percentage of embryos produced using IVM/IVF/IVC. Cyclic heifers (n = 22) were superovulated between Days 8 and 12 of the estrous cycle with 4, 6 or 8 constant doses of FSH-P (4 mg each, twice daily) +/- the addition of 1 mg prostaglandin 24 h before slaughter. Ovaries from these superovulated cows and from untreated cows were collected and the follicles dissected. Oocytes were classified according to the appearance of their cumulus and cytoplasm. Individual culture as well as group culture were performed but an individual culture reduced the percentage of oocytes developing into embryos for both untreated and superovulated animals. The results indicated that despite the superovulation regimen the developmental competence of the oocytes collected was lower (0 to 15% embryos) than that of oocytes from untreated animals (20 to 34% embryos). Small follicles ( < or = 2.7 mm) yielded mostly oocytes with an incomplete or partially expanded cumulus investment that never developed into an embryo. Differences in the morphology of the oocytes from medium (2.7 to 8 mm) and large ( > or = 8 mm) follicles were apparent, but equal developmental rates were obtained between all classes of oocytes (12 and 8% embryos, respectively). Follicular atresia was reduced significantly after superovulation (81% nonatretic follicles in treated vs 42% nonatretic follicles in untreated animals); however oocytes from atretic and slightly atretic follicles developed similarly to those from nonatretic follicles. These results suggest that although superovulation increases follicular size and decreases atresia, these conditions are not sufficient to confer developmental competence on the oocytes.

Journal Article↗

PubMed1994

Oocyte structure and follicular steroid concentrations in superovulated versus unstimulated heifers.

A highly variable yield of viable embryos in superovulated cattle is a major hindrance to the embryo transfer industry. To trace the cause of this problem, investigations were carried out on the intrafollicular steroids and structure of oocytes originating from follicles of follicular stimulating hormone (FSH)-stimulated (superovulated) and unstimulated heifers. Unstimulated heifers were slaughtered at midcycle, or administered cloprostenol (PG) at midcycle and slaughtered after 24, 48, or 72 hr, while superovulated heifers were administered 4 injections of pFSH (2 injections per day) and slaughtered 12 hr later, or administered 6, 7, or 8 injections of FSH in combination with PG at the 5th and 6th injection, and slaughtered 24, 36, or 60 hr, respectively, after the first PG injection. The follicular fluid from the largest (presumptive dominant) follicle of the unstimulated heifers and from potentially ovulatory follicles (> or = 8 mm in diameter) of the superovulated heifers were assayed for estradiol-17 beta (E2) and progesterone (P4), while the oocyte cumulus complexes from such follicles were processed for transmission electron microscopy. The mean E2 and especially P4 concentrations of the potentially ovulatory follicles of the superovulated heifers were lower than similar follicles of the unstimulated animals (83.7 +/- 76.7 ng/ml vs. 208.1 +/- 357.0 ng/ml, P > 0.05 and 31.1 +/- 38.7 ng/ml vs. 150.3 +/- 202, P < 0.05, respectively). The unstimulated oocytes had, in general, spherical oocyte nuclei and compact nucleoli before PG administration, while after PG, undulation of the nuclear envelope and nucleolus vacuolization was characteristic.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1987

Superovulation in immature and mature Chinese hamsters.

Mature female Chinese hamsters ovulate an average of 8.8 +/- 1.0 (mean +/- SD) eggs per female in each estrous cycle. Superovulation can be induced in both immature and mature females by subcutaneous or intraperitoneal injections of pregnant mare serum gonadotropin (PMSG) and either human chorionic gonadotropin (hCG) or pituitary luteinizing hormone (PLH). The best superovulation in immature females was induced by the administration of 15 IU of PMSG followed 72 hr later by injection of 15 IU of hCG (about 25 eggs per female) or 0.2 mg (200 IU) PLH (about 46 eggs per female). Ovulation started about 13-15 hr after administration of hCG (or PLH) and was completed during the next 5-6 hr. Superovulation in mature females could be induced by injecting PMSG any day of the estrous cycle, but the best superovulation (about 39 eggs per female) was induced by injecting 15 IU of PMSG on day 1 (day of ovulation) followed by the injection of 0.4 mg of PLH 72 hr later. When immature females treated with the best superovulatory protocol were mated on the evening of PLH injection, only 5% of the eggs were found fertilized 50 hr after PLH administration. On the other hand, about 60% of the eggs were found fertilized in mature females mated following treatment with the best superovulatory protocol. The majority (83-85%) of superovulated eggs obtained from both immature and mature females were normally fertilized in vitro.

Aging↗

PubMed2004

Timing intrauterine insemination either 33 or 39 hours after administration of human chorionic gonadotropin yields the same pregnancy rates as after superovulation therapy.

OBJECTIVE: To compare a short and long interval between hCG administration and IUI after superovulation for the treatment of infertility. DESIGN: Prospective, randomized clinical trial. SETTING: University hospital-based fertility clinic. PATIENT(S): Patients planning superovulation and IUI for the treatment of infertility. INTERVENTION(S): Patients with >or=2 years of infertility enrolled for superovulation and IUI treatment were randomized to IUI after a short (32-34-hour) or long (38-40-hour) interval after hCG injection. Superovulation was accomplished with hMG or recombinant FSH, with dose adjustment until the maturation of two to five follicles, at which time hCG was given. Sperm was prepared with a gradient centrifugation technique, with IUI performed high up in the uterine fundus. MAIN OUTCOME MEASURE(S): Pregnancy rates. RESULT(S): Of the 348 patient cycles randomized, 270 treatment cycles were initiated. Eighty-one initiated cycles were canceled, leaving 189 completed randomized cycles from 75 patients for analysis. Pregnancy rates were not significantly different between groups. There were pregnancies in 20 of the 96 short hCG-IUI interval cycles (21%) and in 14 of the 93 long hCG-IUI interval cycles (15%) (odds ratio = 0.673, 95% confidence interval 0.297-1.518). CONCLUSION(S): Pregnancy rates are the same after superovulation therapy whether IUI is done after a short or a long interval after hCG injection.

Adult↗

PubMed1997

Randomized controlled trial of superovulation and insemination for infertility associated with minimal or mild endometriosis.

OBJECTIVE: To evaluate the efficacy of superovulation and IUI versus no treatment for infertility associated with minimal or mild endometriosis. DESIGN: Randomized trial. SETTING(S): London Health Sciences Centre, University Campus, The University of Western Ontario, London, Ontario; and Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada. PATIENT(S): Three hundred eleven cycles in 103 couples in whom minimal or mild endometriosis was the sole identified subfertility factor. INTERVENTION(S): Superovulation with FSH and IUI. MAIN OUTCOME MEASURE(S): Live birth. RESULT(S): Live birth followed 14 of 127 (11%) superovulation and IUI cycles and 4 of 184 (2%) no-treatment cycles. The odds ratio was 5.6 (95% confidence interval 1.8 to 17.4) in favor of superovulation and IUI. CONCLUSION(S): Treatment with superovulation and IUI was associated with superior outcome both by crude live-birth rates and proportional hazard analysis.

Adult↗

PubMed2000

Decreased LH pulsatility during initiation of gonadotropin superovulation treatment in the cow: evidence for negative feedback other than estradiol and progesterone.

LH pulse secretion is suppressed during superovulation of cattle. The objective of this study was to determine how soon after initiation of superovulation treatments this suppressive effect occurs, and to test the hypothesis that decreased LH pulsatility is not related to changes in circulating estradiol or progesterone. Heifers (n = 7/group) were injected with eCG (FOLLIGON: a single injection of 2,500 IU) or twice daily injections of decreasing doses of FOLLTROPIN-V (total equivalent of 280 mg of NIH-FSH-P1) or F.S.H.-P (total equivalent of 28 mg of Armour standard) or saline (time controls), starting on Day 10 (Day 0 = estrus). Blood samples were taken every 10 min for 12 h intervals on the day prior to first injection, at 8 to 20 h and 32 to 44 h after initiation of gonadotropin treatment, and also during prostaglandin (PG)-induced luteolysis. A simple method based on robust statistics and on graphical representations of time series was developed to characterize LH pulses. There was a significant interaction between time and treatment for mean LH, estradiol and progesterone when control and treated groups were analyzed together, and no interaction when only the gonadotropin groups were analyzed together. When compared to pretreatment values, pulse frequency of LH was significantly reduced (P<0.05) in each treatment group, 8 to 20 h and 32 to 44 h following initiation of gonadotropin treatment. Mean LH concentrations were also reduced 32 to 44 h following initiation of treatments (P<0.05). Mean estradiol concentrations increased two to threefold at 8 to 20 h following initiation of superovulation treatments (P<0.05). Progesterone concentrations also increased by 20 or 44 h. There was no significant correlation between estradiol or progesterone and LH pulse frequency, amplitude and mean concentrations at any time in control or superovulated animals. This study demonstrates that superovulation treatment in the cow causes a rapid decrease in pulsatile release of LH and suggests that this effect is not mediated through the negative feedback actions of estradiol and progesterone.

Animals↗

PubMed1987

Repeated superovulation and surgical recovery of embryos in the ewe.

Repeated superovulation using three treatments of pFSH at intervals of 45 to 55 days during the same breeding season was carried out in 18 Préalpes ewes. The embryos were recovered by surgery after the first two treatments and by slaughter after the last one at Day 6. Three lots of control ewes (n = 5 or 6) receiving the same superovulation treatment were slaughtered respectively at the same time. The first and third repeated superovulation treatments gave averages of 5.2 +/- 0.6 and 4.5 +/- 0.6 corpora lutea. The second one gave 3.4 +/- 0.4 corpora lutea, which was significantly lower than with treatments 1 and 3, but adhesions did not permit a perfect view of the whole surface of the ovaries. Recovery rates decreased regularly with repeated collection (88.2, 52 and 24%, respectively). The proportion of embryos at the morula/blastocyst stage also decreased from 86 and 93% to 6.7% at the third treatment. The development of post-surgical lesions probably caused variations in the apparent rate of ovulation and a decrease of egg recovery and fertilization rates. In control ewes the mean level of superovulation did not vary significantly during the breeding season and embryonic development was normal when checked at slaughter. Repeated superovulation using pFSH is worthwhile only if the eggs are recovered by perfusion with an appropriate catheter (introduced into the uterus by laparoscopy) instead of by surgery.

Animals↗

PubMed1985

Estimation of superovulation response in donor cows.

Estimates were made of the superovulation response in donor cows using ovarian size, the number of corpora lutea (palpated per rectum) and blood progesterone levels. Neither the estimated number of corpora lutea nor ovarian size gave a satisfactory prediction of superovulation response. There was a large discrepancy between the number of corpora lutea present on the ovaries of nine superovulated cows (166) and the estimated number (106). All the corpora lutea on superovulated ovaries were smaller than normal (1.95 g). Blood progesterone levels at the time of embryo recovery were correlated with both the number of corpora lutea on the superovulated ovaries (r = 0.9, P less than 0.001) and the weight of the corpora lutea (r = 0.95, P less than 0.001). There were 67 embryos and ova recovered from the nine donors, representing 40 per cent of the actual and 63 per cent of the palpated corpora lutea. However, neither ovarian size, the number of corpora lutea nor blood progesterone levels were correlated with embryo production.

Animals↗