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PubMedDate not supplied

Relationship between peri-oestrus progesterone levels and time of ovulation by echography in pigs and influence of the interval between ovulation and artificial insemination (AI) on litter size.

Two methods for the determination of ovulation were compared to one ultrasonography performed 5 times a day. Time of ovulation by echography was 40 +/- 5.8 h (mean +/- SD) after the onset of oestrus. Preovulatory LH rise (two blood samples per day) began near the onset of oestrus but, in our conditions, this parameter could not be used to predict ovulation. The basal level of progesterone (two blood samples per day) was determined with a non-linear model, the timing when progesterone rose more than one SD (0.3 ng x mL(-1)) coincided with the timing of ovulation determined by echography (R2 = 0.98). This method was efficient and was used in a field trial to measure the consequences of the variability of the interval between Al and ovulation on litter size. The interval between Al and ovulation had an effect on litter size; litter size decreased by one piglet when this interval increased by 10h.

Animals↗
PubMed1994

Factors affecting the age at onset of puberty, ovulation rate and time of ovulation in Chinese Meishan gilts.

Experiments were carried out to study: the effects of season on age at puberty, the influence of reproductive age on ovulation rate, and the time interval from the onset of oestrus to ovulation in Chinese Meishan gilts. Gilts approaching puberty either in the spring (n = 88) or in the autumn (n = 40) were housed indoors under natural daylight conditions and observed daily for oestrous behaviour. Gilts approaching puberty in the spring were younger (P < 0.001) and more likely to reach puberty by 100 days of age (P < 0.01) than were those approaching puberty in the autumn. Ovulation rate was estimated in gilts at second (n = 22), third (n = 24), fourth (n = 18), fifth to ninth (n = 9) and tenth to twenty-first (n = 17) oestrous cycle and in primiparous Meishan sows (n = 12) by counting the number of corpora lutea or corpora albicantia at laparoscopy, laparotomy or at ovarian recovery following slaughter. Ovulation rate increased (P < 0.001) with reproductive age and approached that of primiparous sows only when gilts had experienced > or = 10 oestrous cycles (19.2 versus 21.0). The time interval between the onset of oestrus and ovulation was studied in six naturally cyclic Meishan gilts and nine Meishan gilts administered hCG at the onset of oestrus. All glits were observed six times a day for the commencement of oestrous behaviour and were subsequently examined by laparoscopy at 32 h following onset of oestrous and every 8 h till ovulation, which was a maximum of 56 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1990

Evaluation of the accuracy of the home ovulation detection kit, Clearplan, at predicting ovulation.

A home ovulation testing kit, Clearplan, that detects the urinary luteinizing hormone (LH) surge was compared with basal body temperature (BBT) charts and cervical scoring as a method of ovulation prediction in 54 consecutive patients. The accuracy of all these methods was evaluated using daily serum LH measurements. Clearplan was shown to be significantly more accurate at timing ovulation than were BBT charts (P less than 0.0001) and cervical scoring (P less than 0.025). In 82%-88% of cases the kit predicted ovulation within one day and in 89%-96% of cases within two days of the serum LH surge. The kits were found to be easy to use and their potential place in clinical practice is discussed; home ovulation testing may ultimately replace serum LH assays as the method of choice in timing ovulation.

Body Temperature↗
PubMed1979

[Modification of the ovarian cycle, ovulation and reproduction in rat by administration of p-chlorophenylalanine in the pre and post ovulation period (author's transl)].

The effect of p-Chlorophenylalanine (PCPA) administered in pre and post-ovulation phases on ovulation reproduction and ovarian cycle was studied in rats. Vaginal smears, number of ovules, mature follicles and ovaric histologic features were evaluated. PCPA administered in the periods after follicular rupture prolongs the diestrus phase from 2 to 10 consecutive days and totally inhibits the reproductive conduct. When administered in the periods just prior to follicular rupture, PCPA prolongs the estrus phase from 2 to 4 consecutive days and does not totally inhibit reproduction. A progressive increase in reproduction took place as treatment time approached ovulation, to such an extent that the number of inseminated and fertilized rats when treated at the ninth hour of the proestrus phase, was superior to the control group. PCPA administered in periods after and before follicular rupture totally inhibits ovulation in all cases. Ovaries present many mature follicles, as many as in the controls sacrificed at the 18 hour of the proestrus, just before ovulation.

Animals↗
PubMed1988

Ovulation prediction and detection with the CUE Ovulation Predictor.

Predicting ovulation is useful for managing the infertile patient and when done sufficiently in advance for fertility regulation by periodic abstinence. It has been reported that ovulation could be predicted by measurement of salivary and vaginal electrical resistance (SR and VR). These data from 32 menstrual cycles of 23 women were obtained to evaluate this technique. Data of 14 cycles were from subjects receiving clomiphene citrate (CC), while the others were from spontaneously ovulating subjects. A peak in SR was seen 5-7 days before the day of the LH peak in both natural and CC cycles. A correlation coefficient (r) of 0.94 was seen for the day of the SR peak and that of the LH peak. The SR trend was similar in both natural and CC cycles. VR in spontaneous cycles declined to a periovulatory nadir and then increased. The patterns of VR in CC cycles were similar except that values were initially depressed during and shortly after the end of CC therapy. Over 90% of VR increases were on the day of the LH peak and the day following. Results indicate that the method is useful for predicting ovulation in natural and CC cycles. Since the number of days by which ovulation is predicted exceeds the expected lifespan of spermatozoa in the female reproductive tract, the method also shows potential for use in natural family planning.

Electric Conductivity↗
PubMed1989

[The course of ovulation in gilts after the partial replacement of HCG by GnRH for ovulation stimulation].

The ovulation status and the amount of ovulated follicles were determined in 3 experiments from 197 gilts which had been given differentiated treatment and which were subsequently slaughtered. Ovulation stimulation produced high synchronisation effects, as compared to untreated animals. Partial substitution proved possible of Gn-RH vet. "Berlin-Chemie" for 500 I.U. of HCG which were generally used to stimulate ovulation, since the amount of ovulated follicles 169 hours from the last application of Suisynchron premix was in all 3 cases above the specified value of 85.0 per cent even after injection of 300 I.U. HCG/300 micrograms Gn-RH.

Animals↗
PubMed2004

Pharmacokinetics, ovulation suppression and return to ovulation following a lower dose subcutaneous formulation of Depo-Provera.

Depo-Provera is a highly effective contraceptive, given intramuscularly (150 mg/mL) once every 3 months. It has been in use in the United States for over 10 years. A new lower-dose formulation of Depo-Provera (104 mg/0.65 mL), has been developed that allows subcutaneous injection, potentially increasing the convenience, ease of administration and tolerability of this contraceptive. This prospective, randomized, single-center, single-dose trial evaluates the pharmacokinetics of the lower-dose formulation of Depo-Provera and compares the lower-dose formulation to the original formulation with regard to efficacy and duration of ovulation suppression and the return to ovulation at 12 months. While delivering a 30% lower total dose than the intramuscular formulation, the lower-dose formulation of Depo-Provera suppressed ovulation for more than 13 weeks in all subjects and was not affected by body mass index or race. Median time for return to ovulation was 30 weeks, with a 97.4% cumulative rate of return to ovulation at 12 months.

Adolescent↗
PubMed1976

[Studies on biotechnical ovulation synchronization in young cows. 1. Ovulation periods, ovarian findings and fertilization results after use of Metallibur, 750 IE PMS and 250 or 500 IE HCG].

The following treatment was applied to 50 mature young sows in two experiments (22 and 28 animals) throughout 20 days: Turisynchron-Prämix (Turi.), 5 g/animal, and 750 IU PMS (Prolosan serum) 28 hours after Turi. In the first experiment. 250 IU HCG (Gonabion) were additionally injected to each of twelve animals 100 hours after Turi., while in the second experiment each of ten animals recieved 500 IU HCG 103 hours after Turi. The remaining animals of the two groups were used as controls. Inseminations took place 101 and 104 hours (fourth day) after Turi. in the first experiment and 125, 149, as well as 173 hours (fifth, sixth, and seventh days) after Turi. in the second. Onset of ovulation was brought forward to the sixth day after Turi. in response to 500 IU HCG by laparotomy performed in the mornings and evenings of the fourth through seventh days. Most of the controls and test animals with 250 IU HCG ovulated on the sixth or seventh day after Turi. Ovulation was stimulated by both HCG dosages, in comparison to the controls, which was established by slaughtering the animals between the seventh and twelfth days after Turi. The percentage of ovulations was higher among the test animals and that of ovarian cysts lower. Fertilisation of the second group was clearly better than that in the first where insemination had taken place two days prior to ovulation, that is too early. The latter results were secured by tubal douche and ovocyte tests.

Animals↗
PubMed1999

Time of ovulation in the brushtail possum (Trichosurus vulpecula) following PMSG/LH induced ovulation.

This study aimed to determine the timing of ovulation in response to a new induced ovulation regime for the monovulatory brushtail possum (Trichosurus vulpecula). Ovarian stimulation was achieved by a single subcutaneous injection of 15 i.u. pregnant mare serum gonadotrophin (PMSG). This treatment resulted in promotion of a large number (9-16) of Graafian follicles > 2 mm diameter on the ovaries. Seventy-two hours later a single intramuscular injection of 4 mg porcine luteinizing hormone (LH) was administered to induce ovulation. Groups of possums were killed 24 hr post-LH injection and subsequent groups were killed at 6-hr periods up to 48 hr later. Ovulation occurred from 30 hr to 42 hr post-LH. The ovulatory success increased from 3% at 30 hr post-LH to 83% at 48 hr post-LH. Oocytes were recovered primarily from the oviducts at 36 hr post-LH. Thereafter oocytes were recovered increasingly from the uteri and by 48 hr post-LH, were only found there. The implications of these observations for artificial breeding in possums are discussed.

Animals↗
PubMed1999

Factors that influence follicle recruitment, growth and ovulation during ovarian superstimulation in heifers: opportunities to increase ovulation rate and embryo recovery by delaying the exposure of follicles to LH.

The outcome of ovarian follicular superstimulation protocols in heifers is influenced by the number of follicles that are stimulated to grow and the number induced to ovulate. At present, only a proportion of the follicles that are stimulated to grow progress to ovulation. The argument is developed in this review that failure of some of these follicles to ovulate may be due not to an intrinsic deficiency but rather to their relatively small size when the FSH treatment is initiated. Consequently, these follicles do not have the opportunity to undergo full maturation within the time frame of a conventional superstimulation protocol Based on this argument, we propose that delaying the LH surge would allow for completion of maturation by a greater number of follicles, resulting in an increased ovulation rate and in recovery of a greater number of viable embryos.

Animals↗
PubMed1989

[The course of ovulation in gilts after the use of two GnRH injections for ovulation stimulation].

The status of ovulation and amount of ovulated follicles in 410 gilts which had received differentiated pretreatment produced evidence to the feasibility of substitution of HCG by Gn-RH vet. "Berlin-Chemie" to stimulate ovulation. Yet, 2 injections are necessary with an adequate interval between them and with appropriate dosage. The highest synchronisation effect in all experimental variants was obtained from 350 and 750 micrograms of Gn-RH with 50 minutes in between or 750 plus 750 micrograms of Gn-RH with an interval of 40 minutes. Ovulation was most reliably stimulated by 500 I.U. of HCG.

Animals↗
PubMed1978

[Ovulation in gilts following biotechnical puberty induction and followed by ovulation stimulation].

Eighty gilts were slaughtered following different time intervals from biotechnical puberty induction, using 500 IU or PMS and 250 IU of HCG, and stimulation of ovulation, using 500 IU of HCG, 72 hours after puberty had been induced. The majority of those animals was found to have ovulated between 96 and 120 hours from puberty induction. Only 3.2 per cent of the follicles formed had undergone ovulation after 96 hours but as much as 94,0 per cent after 120. Not only had sexual maturity been reached by all animals, following the above treatment, but genuine superovulation was recordable from the first oestrus, with the average of formed follicles being 23.9. Stimulation of ovulation following puberty induction, therefore, is considered to be useful in providing favourable conditions for effective time-oriented insemination.

Animals↗
PubMed1976

[Studies on biotechnical ovulation synchronization in young sows. 3. Report: ovulation onset, ovarian findings and results of fertilization after metallibur, 750 IU PMS, with and without 500 IU HCG with varied treatment time].

Fourty-eight gilts were treated with Turisynchron-Prämix (Turi.) and PMS (750 IU; 24-hours a. Turi.). One-half of the animals receaved additionally 500 IU HCG (fourth day a. Turi.). Performing treatments (Turi., PMS, HCG) either between 8 and 9 a.m. or 3 and 4 p.m. resulted in 2 experimental (HCG) and 2 control (without HCG) groups, each consisting of 12 animals. Double insemination took place according to treatment times at the fifth or the fifth and sixth day a. Turi. The experimental animals underwent laparotomy at the sixth day between 9 and 12 a.m., the conerols between 1 and 4 p.m. at the sixth or 9 and 12 a.m., at the seventh day a. Turi. Oviducts were flushed either at laparatomy or on slaughter to establish fertilization. From 24 experimental animals 20 ones had ovulated between 42-53 h p. HCG, and at slaughter 22 did so. The period of ovulation is mainly assumed near and immediately after 42 h p. HCG. In controls ovulation could be established in 3 of 15 animals laparotomized up to 152 h a. Turi. and in 8 of 9 animals laparotomized up to 168 h a. Turi. At slaughter there were in all 22 animals of the 2 control groups which had ovulated. In the rate of ovarian cysts (25-33%) and fertilized ova no remarkable differences were found between the groups.

Animals↗
PubMed2003

Timing of ovulation and conception rate in primiparous and multiparous cows after synchronization of ovulation with GnRH and PGF2alpha.

Conception rates after Ovsynch have been higher in primiparous than in multiparous cows. The objective of this study was to investigate whether this difference might be due to differences in ovulation rate or follicular size. The experiment was conducted with 136 Holstein Frisian cows from a commercial herd in Brandenburg, Germany. All cows were synchronized using Buserelin (GnRH analogue) at day -10, Tiaprost (PGF2alpha analogue) at day -3 and again GnRH at day -1. Timed artificial insemination (TAI) was carried out 16-20 h after the second dose of GnRH on day 0. Milk samples for analysis of milk progesterone were obtained on days -17, -10, -3 and at TAI. Progesterone concentrations were used to determine the stage of oestrus cycle at the start of the synchronization protocol and to investigate the presence of functional luteal tissue before treatment with PGF2alpha and TAI. All animals were examined by ultrasound at the second treatment with GnRH, at AI, 8 and 24 h after AI. Overall synchronization rate (proportion of cows with an ovulation within 40 h after GnRH) was 86.8% in primiparous and 88.2% in multiparous cows, respectively. Ovulation occurred earlier in primparous than in multiparous cows (p < 0.05) and ovulatory follicles were smaller. Conception rates were numerically higher in primiparous cows but the difference was not significant. Cows that displayed signs of oestrus on day -1 and received an additional AI on this day were more likely to conceive than cows that only received TAI 16 to 20 h after GnRH2. It is concluded that ovulation occurs earlier in primiparous than in multiparous cows after Ovsynch. However, a significant relationship between these differences and the probability of conception could not be established.

Animals↗
PubMed2005

Transient expression of CC chemokine TECK in the ovary during ovulation: its potential role in ovulation.

PROBLEM: Chemokine thymus-expressed chemokine (TECK), which is expressed exclusively in the thymus and small intestine, plays a critical role in T-cell development. Our previous study revealed its expression in the ovary also. This study investigated its ovarian expression during ovulatory process. METHOD OF STUDY: Super-ovulation was induced in young female CD1 mice by equine chorionic gonadotropin (eCG) and human chorionic gonadotropic (hCG). Ovarian TECK expression during ovulation was determined by: (1) reverse transcriptase-polymerase chain reaction (RT-PCR) at mRNA level, (2) Western blot and immunohistology at the protein level, and (3) leukocyte infiltration assay at the bioactive level. RESULTS: A transient, high-level expression of TECK in murine ovaries at the mRNA level during hCG-induced ovulation was detected. Sequencing of directly cloned PCR product confirmed the ovarian expression of TECK. The peak expression of TECK was observed at 10-12 hr post-hCG injection; real-time PCR revealed an 800-fold increase during its expression peak over 0 hr. The expressed ovarian TECK protein was readily detectable by Western blot. Immunohistochemistry localized TECK expression to the ovarian interstitial tissue surrounding, or in the theca layer of the mature follicles undergoing ovulatory process. Expression of TECK receptor, the CC chemokine receptor (CCR9) was also detected in the ovulating ovaries. Using in vitro leukocyte infiltration assay, we first demonstrated that ovaries undergoing the ovulatory process were able to selectively chemoattract mononuclear cells. Importantly, neutralization of TECK by the antibody resulted in a 85% reduction in the chemotactic activities of the ovaries. CONCLUSION: This study suggested that ovarian expression of TECK is under a tight hormonal regulation, and expressed TECK may be responsible for recruitment of mononuclear cells into the ovary to participate in the ovulatory process.

Animals↗
PubMed1996

A comparison of the ovulation method with the CUE ovulation predictor in determining the fertile period.

The purpose of this study was to compare the CUE Ovulation Predictor with the ovulation method in determining the fertile period. Eleven regularly ovulating women measured their salivary and vaginal electrical resistance (ER) with the CUE, observed their cervical-vaginal mucus, and measured their urine for a luteinizing hormone (LH) surge on a daily basis. Data from 21 menstrual cycles showed no statistical difference (T = 0.33, p = 0.63) between the CUE fertile period, which ranged from 5 to 10 days (mean = 6.7 days, SD = 1.6), and the fertile period of the ovulation method, which ranged from 4 to 9 days (mean = 6.5 days, SD = 2.0). The CUE has potential as an adjunctive device in the learning and use of natural family planning methods.

Adult↗
PubMed1968

Pregnancy following coital-induced ovulation in a spontaneous ovulator.

Ovulation induced in the immature rat by pregnant mare's serum can be prevented by chlorpromazine. Coitus induces ovulation in such animals, and ovulation so induced may result in pregnancy. Both implantation and pregnancy appear to be normal although the duration of gestation may be prolonged. Decidual response also is produced in the immature rat after coitus-induced ovulation. We suggest that the reflex release of luteinizing hormone may occur in Primates after coitus.

Animals↗
PubMed1981

Duration of oestrus, ovulation rate, time of ovulation and plasma LH, total oestrogen and progesterone in Galway adult ewes and ewe lambs.

The mean duration of oestrus, ovulation rate, duration of the preovulatory LH discharge, time interval between sponge removal and beginning of the LH discharge, total LH discharged, maximum LH value observed and the concentration of progesterone in the peripheral plasma during the luteal phase of the oestrous cycle was similar in Galway adult ewes and 8-month-old ewe lambs after treatment with intravaginal sponges containing 30 mg cronolone for 12 days and injection of 500 i.u. PMSG. The interval between sponge removal and the onset of oestrus was shorter for adults than for ewe lambs; the interval between the onset of oestrus and the beginning of the LH discharge was longer in adults. During the period 12-36 h after sponge removal the mean plasma total oestrogen concentration was significantly higher in lambs than in adults. In a separate study of the time of ovulation in Galway ewe lambs given the same progestagen-PMSG treatment, ovulation did not occur in any lamb before 17 h after the onset of oestrus and the majority ovulated close to the end of oestrus.

Animals↗