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PubMed1994

Uterine capacity and ovulation rate in mice selected 21 generations on alternative criteria to increase litter size.

After 21 generations of selection for alternative criteria to change litter size in mice, responses in uterine capacity and ovulation rate were evaluated. Females from Generations 22 and 23 were sampled from 12 lines, representing three replicates of four selection criteria: LS = direct selection on litter size; IX = selection on an index of ovulation rate and the proportion of ova shed that resulted in fully formed offspring; UT = selection on uterine capacity measured as litter size from females unilaterally ovariectomized at 4 wk of age; and LC = unselected control. All females in the present evaluation (a total of 1,932) were unilaterally ovariectomized (either left or right ovary excised) at 4 wk, mated at 9 wk, and killed at d 17 of gestation. The number of corpora lutea and number of fetuses were counted to measure ovulation rate and uterine capacity, respectively. Selection in IX, LS, and UT increased (P < .01) ovulation rate from unilaterally ovariectomized females but by a greater amount (P < .01) in IX and LS than in UT. Selection also increased (P < .01) uterine capacity of IX, LS, and UT (average response relative to LC = 1.76 pups); response was at least as great in LS and IX as in UT. Direct selection in UT was successful at improving uterine capacity but was no more effective than IX or LS selection. Cases in which ovulation rate limited expression of uterine capacity in UT may have shifted some selection emphasis to ovulation rate and reduced response in uterine capacity.

Animals↗
PubMed1996

Relationship of weaning-to-estrus interval to timing of ovulation and fertilization in sows.

Data from two experiments were used to study the relationship between weaning-to-estrus interval (WEI, varying from 3 to 6 d) and the duration of estrus, the interval from onset of estrus to ovulation and fertilization results at 120 h after ovulation, in 201 multiparous sows. An increase in WEI resulted in a decrease in the duration of estrus (Duration of estrus (h) = [81 (exp1) or 88 (exp2)]-.33 x WEI, R2 = .25, P < .001) and a decrease in the interval from onset of estrus to ovulation (onset estrus to ovulation (h) = [54 (exp1) or 59 (exp2)]-.20 x WEI, R2 = .23, P < .001). Sows that were inseminated between 0 and 24 h before ovulation showed consistent high fertilization results (91% normal embryos), irrespective of WEI. Sows that were inseminated outside this range showed an increased proportion of unfertilized eggs (P < .001). This increase occurred similarly in all weaning to estrus intervals. These results suggest that negative effects of a longer WEI on subsequent litter sizes and farrowing rates as described in literature might be a result of suboptimal timing of insemination relative to ovulation and not of poor fertility in these sows.

Animals↗
PubMed2002

Seasonal effects on estrous behavior and time of ovulation in nonlactating beef cows.

Estrous behavior and time of ovulation relative to the onset of estrus were determined in mature Angus x Hereford cows (n = 17 to 21 each season) during summer, winter, and spring for 2 yr. Estrous behavior was evaluated during the first of two consecutive estrous periods, and time of ovulation was determined during the second estrus. Concentrations of progesterone were quantified in twice weekly blood samples to ensure all cows had normal estrous cycles. The HeatWatch system was used to measure the duration of estrus, number of mounts received per estrus, and duration of the longest interval between mounts received. Commencing 16 h after the onset of the second estrus, transrectal ultrasonography was performed every 4 h until the dominant follicle was no longer present on the ovary, and time of ovulation was defined as 2 h preceding the absence of the dominant follicle. There was a seasonal effect on the duration of estrus; cows were estrus longer in summer (17.6 +/- 0.8 h) than in winter (15.5 +/- 0.8 h; P = 0.07) or spring (13.9 +/- 0.9 h; P < 0.05). Cows were mounted more times per estrus (P < 0.05) in winter (59.0 +/- 5.3) than in summer (43.6 +/- 5.3) or spring (38.2 +/- 5.8). Intervals between mounts of estrous cows were longer (P < 0.05) in summer (4.1 +/- 0.4 h) than in spring or winter (2.7 +/- 0.4 h). During all seasons, cows were mounted more times (P < 0.01) between 0600 to 1200 (3.2 +/- 0.2 mounts received/h of estrus) than during other times of the day (2.1 +/- 0.2 mounts received/h of estrus). Cows ovulated 31.1 +/- 0.6 h after the onset of estrus, and time of ovulation was not influenced by season. We conclude that season influences estrous behavior of beef cows; cows are mounted more times per estrus in winter than in summer or spring. Time of ovulation relative to the onset of estrus is constant during all seasons and averages 31.1 h.

Animals↗
PubMed2005

Effect of age and physical or fence-line boar exposure on estrus and ovulation response in prepubertal gilts administered PG600.

Boar exposure has been used for estrus induction of prepubertal gilts, but has limited effect on estrus synchronization within 7 d of introduction. In contrast, PG600 (400 IU of PMSG and 200 IU of hCG; Intervet, Millsboro, DE) is effective for induction of synchronized estrus, but the response is often variable. It is unknown whether boar exposure before PG600 administration might improve the efficiency of estrus induction of prepubertal gilts. In Exp. 1, physical or fence-line boar contact for 19 d was evaluated for inducing puberty in gilts before administration of i.m. PG600. Exp. 2 investigated whether 4-d boar exposure and gilt age influenced response to PG600. In Exp. 1, 150-d-old prepubertal gilts were randomly allotted to receive fence-line (n = 27, FBE) or physical (n = 29, PBE) boar exposure. Gilts were provided exposure to a mature boar for 30 min daily. All gilts received PG600 at 169 d of age. Estrous detection continued for 20 d after injection. In Exp. 2, prepubertal gilts were allotted by age group (160 or 180 d) to receive no boar exposure (NBE) or 4 d of fence-line boar exposure (BE) for 30 min daily before receiving PG600 either i.m. or s.c. Following PG600 administration, detection for estrus occurred twice-daily using fence-line boar exposure for 7 d. Results of Exp. 1 indicated no differences between FBE and PBE on estrus (77%), age at puberty (170 d), interval from PG600 to estrus (4 d), gilts ovulating (67%), or ovulation rate (12 corpora lutea, CL). Results from Exp. 2 indicated no effect of age group on estrus (55%) and days from PG600 to estrus (4 d). A greater (P < 0.05) proportion of BE gilts expressed estrus (65 vs. 47%), had a shorter (P < 0.05) interval from PG600 to estrus (3.6 vs. 4.3 d), and had decreased (P < 0.05) age at estrus (174 vs. 189 d) compared with NBE. Ovulation rate was greater (P < 0.05) in the BE group for the 180-d-old gilts (12.7 vs. 11.9 CL) compared with the NBE group. However, age group had no effect on ovulation (77%) or ovulation rate (12 CL). Collectively, these results indicate that physical boar contact may not be necessary when used in conjunction with PG600 to induce early puberty. The administration of PG600 to 180-d-old gilts in conjunction with 4 d prior fence-line boar exposure may improve induction of estrus, ovulation, and decrease age at puberty.

Age Factors↗
PubMed1983

Luteal phase insufficiency in the ewe as a consequence of premature induction of ovulation by intrafollicular injection of gonadotropins.

The largest ovarian follicle of ewes was injected on d 15 of the estrous cycle (2 to 3 d before the anticipated preovulatory surge of gonadotropins) with saline or either luteinizing hormone (LH) or follicle-stimulating hormone (FSH) in saline (5 micrograms). Ovulation was assumed based on the presence of an ovulation stigma at d 5 post-treatment. Control animals expressed estrus 2 to 3 d after treatment with saline, and during the estrous period ovulated from the treated follicle. Gonadotropin-treated animals ovulated from injected follicles prematurely and did not exhibit estrus. The stated observations with respect to time of ovulation were established by visual and hormonal criteria: (1) control follicles appeared to have ruptured within a day or two prior to relaparotomy (corpora hemorrhagica), whereas gonadotropin-treated follicles were in a more advanced stage of luteal development (corpora lutea); and (2) concentrations of systemic sera progesterone rose (P less than .05) in LH- and FSH-treated ewes 2d before such an increase in control animals. Luteal function was assessed by comparing sera concentrations of progesterone throughout the induced and spontaneous (vehicle controls) luteal phases. Premature stimulation of ovulation with either gonadotropin was followed by suppressed luteal function (maximum sera levels of progesterone in gonadotropin-treated animals and controls were slightly greater than 1 ng/ml and nearly 2.5 ng/ml, respectively; P less than .01). No differences in the level of luteal function due to treatment with LH or FSH were observed. The duration of the luteal phases of gonadotropin-treated animals were similar to controls (approximately 17 d).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Ovulation side and ovarian cancer.

Previous reports have suggested a predilection for right-sided ovulation and that epithelial ovarian cancer arises more commonly in the right ovary, thus establishing a possible causal relationship between ovulation and ovarian cancer. However, evaluation of ovulation patterns in consecutive cycles has produced contradictory results and there are no reports corroborating a higher incidence of right-sided ovarian cancers. We reviewed the records of 293 patients with epithelial ovarian cancer and found no significant difference between the frequency of tumors in the right and left ovaries. We also prospectively analyzed the side of ovulation in 41 unselected consecutive patients undergoing 156 in vitro fertilization cycles without ovarian stimulation. Follicular development was carefully monitored by daily ultrasonic scan and estradiol and LH plasma determinations. Eight-two ovulations (52%) were on the right (not statistically significant). Thus our results bring into question previous studies suggesting a link between the side of ovulation and epithelial ovarian cancer.

Adult↗
PubMed2006

Time and incidence of ovulation and conception rates after incorporating estradiol cypionate into a timed artificial insemination protocol.

Two experiments were conducted to determine the effect of estradiol cypionate (ECP), when incorporated into a conventional GnRH-PGF(2alpha)-GnRH timed artificial insemination protocol (Ovsynch), on systemic estradiol (E(2)), time and incidence of ovulation, luteal development, and conception rate in Holstein cows. Our objective was to determine if administration of 0.25 mg of ECP at the time of the second GnRH injection would effectively synchronize ovulation and increase conception rate. In Experiment 1, lactating Holstein cows (n = 23; 58.7 +/- 1.2 d in milk) were synchronized with PGF(2alpha) (at d -10). Ten days later, Ovsynch was initiated with the administration of 100 mug of GnRH (d 0) followed by PGF(2alpha) on d 7. On d 9, cows were assigned randomly to be treated with either GnRH + 0.25 mg of ECP (OVS-ECP; n = 11) or GnRH and 1 mL of cottonseed oil (OVS-C; n = 12). Ovarian activity was monitored by ultrasonography on d 0, 7, and 9. To determine the time of ovulation, ultrasound examinations were conducted at 12 and 20 h posttreatment and then at least every 3 h until either 36 h posttreatment or ovulation was observed. Blood samples were collected on d 0, 7, 9, and 16 for progesterone analysis. Blood samples also were collected at the time of treatment (d 9, 0 h) and at 6, 12, 20, and 28 h for E(2) analysis. Incidence of ovulation did not differ between treatments. Mean ovulation time relative to the second GnRH administration was similar between treatments. Serum progesterone concentration did not differ between treatments at any time. Serum E(2) concentration was not different at the time of treatment (0 h); however, mean E(2) concentration was greater for the OVS-ECP group at 6 and 12 h after treatment compared with OVS-C. In Experiment 2, lactating dairy cows (n = 333) in 3 commercial herds were randomly assigned to OVS-ECP (n = 169) or OVS-C (n = 164). Cows were inseminated 22 to 24 h posttreatment. Conception rates did not differ between treatments. Estradiol cypionate treatment was successful in increasing serum E(2) when administered at the time of the second dose of GnRH in the Ovsynch protocol. Conception rates, however, were not affected by treatment.

Animals↗
PubMed2006

Optimizing ovulation to first GnRH improved outcomes to each hormonal injection of ovsynch in lactating dairy cows.

Ovulatory response to the first GnRH of Ovsynch is the critical determinant for successful synchronization of ovulation in dairy cows. Our objective in this study was to develop a pre-Ovsynch treatment that increased the percentage of cows that ovulated in response to the first GnRH injection of Ovsynch. To accomplish our goal, we evaluated a hormonal strategy that consisted of PGF2alpha and GnRH before the first GnRH of Ovsynch. Lactating dairy cows (n = 137) were assigned to receive either no treatment before Ovsynch (control) or 25 mg of PGF2alpha (PreP) followed 2 d later by 100 microg of GnRH (PreG), administered 4 (G4G), 5 (G5G), or 6 (G6G) d before initiating the Ovsynch protocol. Transrectal ultrasonography was performed to assess follicular size and resulting ovulation, and blood samples were collected to measure circulating concentrations of progesterone and estradiol immediately before each hormonal injection. Cows were inseminated at a fixed time 16 h after final GnRH of Ovsynch. Pregnancy diagnosis was performed 35 d later by palpation per rectum of uterine contents. Proportion of cows that ovulated to first GnRH of Ovsynch was 56.0, 66.7, 84.6, and 53.8% for G4G, G5G, G6G, and controls, respectively, and was greater for G6G than for control cows. Luteolytic response to PGF2alpha of Ovsynch was greater in all treated than control cows (92.0, 91.7, 96.2, and 69.2% for G4G, G5G, G6G, and control, respectively). Synchronization rate to Ovsynch was greater (92 vs. 69%, respectively) in G6G than in control cows. In addition, cows that ovulated in response to first GnRH of Ovsynch had greater response to PGF2alpha of Ovsynch (92.7 vs. 77.1%, respectively) and greater synchronization rate to the overall protocol (87.9 vs. 62.9%, respectively) than those that did not ovulate. Concentrations of progesterone at PGF2alpha of Ovsynch, and estradiol and follicle size at final GnRH of Ovsynch, were identified as significant predictors of probability of pregnancy 35 d after artificial insemination. In summary, a PGF2alpha-and-GnRH based pre-Ovsynch strategy consisting of a 6-d interval between PreG and first GnRH of Ovsynch resulted in a greater ovulatory and luteolytic response to first GnRH and PGF2alpha of Ovsynch, respectively, compared with control cows. This, in turn, optimized synchronization rate to Ovsynch.

Animals↗
PubMed1979

Plasma concentrations of progesterone and corticosterone during the ovulation cycle of the hen (Gallus domesticus).

The observation that injections of either ACTH or corticosterone induced ovulation in the hen has prompted speculation which implicates the adrenal gland in the mechanisms controlling ovulation. In this study, the role of the major adrenal steroid in birds was further examined by measuring the plasma concentration of corticosterone during the 24 hr period preceding mid-sequence ovipositions and the 28 hr period preceding terminal ovipositions. Progesterone, which is an accurate index of preovulatory ovarian activity, was also measured in the same samples. An increase in plasma progesterone preceded mid-sequence ovipositions which are accompanied by an ovulation. This preovulatory surge in plasma progesterone began approximately 7 hr before ovulation, reached a maximum of 6.9 ng/ml 3 to 2 hr before ovulation, and returned to baseline concentrations at the time of ovulation. A major preovulatory peak of progesterone was not observed during the interval between sequences, although a small but statistically significant rise in progesterone was observed between midnight and 0600 hr on the day of the last oviposition of the sequence. The concentration of corticosterone increased approximately two-fold during the dark portion of the photoperiod regardless of the position of the oviposition in the sequence. Baseline concentrations during the illuminated portion of the photoperiod ranged between 1 and 4 ng of corticosterone per ml of plasma whereas during the period of darkness, they ranged between 2 and 6 ng of corticosterone per ml of plasma. It was concluded, therefore, that the circulating concentration of corticosterone was regulated by a circadian rhythm which operates independently of follicular maturation.

Animals↗
PubMed1999

Ovarian cancer and ovulation induction drugs--is there a link?

Screening for ovarian cancer in a group of women with induced ovulations was encouraged by recently reported controversies about a possible association between the use of ovulation induction drugs and the increased risk of ovarian carcinoma. Transvaginal color Doppler ultrasonography was applied in screening for early stage ovarian malignoma in 110 asymptomatic women who received an ovulation induction therapy for infertility. Already reported standard parameters for discriminating malignant from benign flows, such as resistance index RI < 0.40, pulsatility index PI < 1 and morphological score (borders, cyst quality, septate areas, papilla and ovarian tissue echogenicity) were used. Screening included 110 women and was carried out from April 1, 1198 to March 31, 1999. Seven examinees had abnormal ovarian findings. The finding spontaneously regressed in five of them, one underwent surgery for a persistent cyst with a benign pathohistologic diagnosis, and one was diagnosed with early stage ovarian malignoma. RI < 0.40 was reported in one patient (0.9%) with a morphologically suspect finding and a pathohistologically confirmed malignoma, PI < 1 was found in 40 subjects or 36.4%, while malignoma was demonstrated in one case alone. The results showed the advantage of RI over PI in discriminating malignant from benign structures. The association between the use of ovulation stimulation drugs and the increased risk of ovarian carcinoma remains unproved and also challenges new dilemmas. The paper cautions against undesirable, potentially serious long-term effects of the use of ovulation induction agents. Additional trials should therefore be performed including a long-term prospective follow-up of women with induced ovulations.

Adult↗
PubMedDate not supplied

[Effects of the antagonist of the classical progesterone receptor on ovulation and maturation of common frog (Rana temporaria L.) oocytes in vitro].

Progesterone induces maturation and ovulation of amphibian oocytes and, in the process, binds to the receptors in oocytes and follicle cells. It is still unclear to what extent the progesterone receptors in these cells are similar. We tried to answer this question using RU486, an antagonist of the classical mammalian progesterone receptor. Pretreatment of the ovarian follicles with RU486 (1-20 microM) does not affect the maturation or ovulation of the common frog oocytes stimulated in vitro by pituitary hormones or progesterone and even increases (at low concentrations) the percentage of maturated and ovulated oocytes. In addition, RU486 (5-40 microM) stimulates the oocyte maturation and ovulation in a dose-dependent manner. Pretreatment of the follicles with actinomycin D (5 microM) inhibits both RU486-stimulated processes. An increase in RU486 concentration overcomes the inhibitory effect of actinomycin D on oocyte maturation. On the contrary, the inhibitory AD effect on oocyte ovulation does not depend on the RU486 concentration. RU486 stimulates the maturation of both follicle-enclosed and "denuded" oocytes. However, the sensitivity of the latter to RU486 is much lower and its effect on the denuded oocyte is not inhibited by actinomycin D. The data obtained suggest that in amphibians, unlike in mammals, RU486 is an agonist of progesterone. It stimulates the transcription-independent maturation of denuded oocytes (membrane receptor) and transcription-dependent ovulation (classical receptor). In addition RU486 can stimulate (at certain doses) the transcription-dependent maturation of follicle-enclosed oocytes.

Animals↗
PubMed1992

Occurrence of ovulation after intracerebroventricular infusion of substance P in 6-OHDA pretreated female rats.

Substance P (SP) infused into the third cerebral ventricle blocks spontaneous ovulation in female rats, probably through catecholaminergic neurons. The studies presented in this paper were undertaken to investigate whether SP exerts its suppressing effect on ovulation in 6-hydroxydopamine (6-OHDA) pretreated female rats. After 8-12 days following 6-OHDA pretreatment female rats were infused, on the day of proestrus, with vehicle and all animals were found to ovulate or with a solution containing 5 nmol of SP and 89% of female rats were then found to ovulate. In the group pretreated with vehicle and subsequently infused with SP, ovulation was found to occur only in 25% of animals. The obtained results indicate that spontaneous ovulation in 6-OHDA-pretreated female rats cannot be blocked by i.c.v. administration of SP, and it may be concluded that SP exerts its suppressing effect through the monoaminergic neurons.

Animals↗
PubMed2003

Oocyte-derived growth factors and ovulation rate in sheep.

The physiological mechanisms controlling ovulation rate in mammals involve a complex exchange of endocrine signals between the pituitary gland and the ovary, and a localized exchange of intraovarian hormones between the oocyte and its adjacent somatic cells. The discoveries in sheep of mutations in bone morphogenetic protein 15 (BMP15) and bone morphogenetic protein receptor type IB (BMPR-IB) together with recent findings on the physiological effects of growth differentiation factor 9 (GDF9) and BMP15 on follicular development and ovulation rate highlight some important differences in the way in which the oocyte may function in mammals with different ovulation rate phenotypes. In sheep, BMP15 and GDF9 have each been shown to be essential for the early and later stages of follicular development. In addition, ovulation rate is sensitive to changes in the dose of either of these two oocyte-derived growth factors. These findings are in contrast to those reported for mice in which GDF9, but not BMP15, is essential for follicular development. The evidence to date is consistent with the hypothesis that the oocyte plays a central role in regulating key events in the process of follicular development and hence, is important in determining ovulation rate. Moreover, it appears that the mechanisms that the oocyte uses to control these processes differ between species with low and high ovulation rate phenotypes.

Animals↗
PubMed2002

[The impact of night work near the day of ovulation on outcome of pregnancy].

OBJECTIVE: To investigate the effect of night work near the day of ovulation on outcome of pregnancy. METHODS: Daily early morning urine samples were collected from eligible shift women workers, and human chorionic gonadotropin(hCG), follicle-stimulating hormone(FSH), the urinary steroid metabolites of estrogen and progesterone(PDG, E1C) were measured to confirm the day of ovulation and early fetal loss(EFL). Questionnaires were used to know workshift, other occupation exposures, and related information. RESULTS: 12 clinical spontaneous abortion(SAB), 18(EFL) and 44 clinical living birth were analyzed in relation to SAB, EFL and night shift near the day of ovulation by using single factor and multi-factor logistic regression. The result showed that night shift on the day of ovulation and the day before or after ovulation was related with SAB both in single- and muti-factorial analysis(single factor: OR = 2.48, 95% CI 1.10-5.60; multi-factor; OR = 3.90, 95% CI 1.28-11.90). CONCLUSION: Night shift near the day of ovulation may be related to SAB.

Abortion, Spontaneous↗
PubMed1979

[Supression by copulation of the inhibitory effect of p-chlorophenylalanine on rat ovulation (author's transl)].

The effect of copulating on reflex ovulation was studied in rat. The effect of PCPA (300 mg/kg, i.p.) on ovulation and reproduction was compared by evaluating number of oocytes in tubes, histologic features of ovaries, vaginal cycle, insemination, fertilization and number of embryos per rat. PCPA, administered on 9th and 16th h of the estrus phase, totally inhibits ovulation, stimulates reproductive behaviour and prolongs the estrogenic phase. When the animals are kept in copulatory conditions for 16 or 46 hours, the inhibition induced in ovulation disappears to the extent that 60% of the rats become pregnant though the number of embryos is under that of the control group. The farther the treatment with PCPA within the same cycle in the ovulatory period, the greater the inhibitory effect on ovulation is and the lesser the neutralizing effect produced by reflexes related to copulation. Administration of PCPA at the 16 hour of the diestrus causes a greater increase in the average number of embryos-as compared to administration at the 9 hour. In periods longer than 48 hours before ovulation, the inhibition brought about by PCPA is not suppressed by copulatory conditions kept for 16 or 24 hours and is only neutralized if they are kept during a complete cycle. Those treated with PCPA in the diestrus phase and maintained in copulatory conditions for 46 hours, present a higher average of embryos than those maintained in similar conditions for 16 hours.

Animals↗
PubMed1991

[Reproduction of French Angora rabbits: ovulation in the female, semen production in the male].

Ovulation rate and semen quality in French Angora rabbits were investigated to determine the potential of improving breeding practices in this breed. The proportion of does ovulating and their ovulation rate were studied in 40 females, as well as sexual behaviour and semen quality in 8 males. The experiments took place in autumn 1987 and were repeated in winter. Three groups of does were injected with 25, 50 IU hCG or 0.8 microgram GnRH (groups 1, 2 and 3, respectively). Another group was mated and served as a control (group 4). Hormonal treatments improved the proportion of does which ovulated (95, 90, 74 and 28% in groups 1-4, respectively; P less than 0.05) but did not change their ovulation rate (10.9 +/- 0.7, 10.7 +/- 0.7, 11.3 +/- 0.8 and 8.9 +/- 1.3 corpora lutea per ovulating female, groups 1-4, respectively; m +/- SEM, NS). In males, two ejaculates were collected twice weekly for 3.5 weeks from 8 bucks. Ejaculates obtained in March were better than those collected in November (volume: 0.33 vs 0.23 ml, P less than 0.01; raw motility: 5.2 vs 3.9, P less than 0.01; individual motility: 2.7 vs 2.1, P less than 0.05; number of living spermatozoa per ejaculate: 71 vs 28 x 10(6), P less than 0.01, respectively). These results suggest that artificial insemination may be utilized to improve reproductive performance in French Angora rabbits.

Animals↗
PubMed1990

Methods of ovulation induction.

The results of ovulation induction in patients with ovulatory dysfunction were reviewed for a one year period. Eighty-six women were assigned to four groups: secondary amenorrhea, anovulation, oligo-ovulation, and luteal phase defect/short luteal phase (LPD). All patients were monitored with basal body temperature (BBT) graph, postcoital testing, and ultrasonic scanning of ovarian follicles. All patients received therapy with clomiphene citrate (CC) for a minimum of four cycles and 13 patients conceived. Fifty patients were offered additional therapy with human menopausal gonadotropins (HMG-HCG). Seventeen completed a minimum of four cycles, and 13 conceived. The number of CC-treated patients with poor mucus quality in the face of adequate follicular development was 24, or 48%. The overwhelming problem with ovulation induction when CC failed was the large number of patients who dropped out of therapy, 48%. In summary, close monitoring during ovulation induction to confirm ovulation, and assess mucus quality and luteal function allow detection and correction of inadequate response. Induction of ovulation can be highly successful if patients can follow through and complete protocols of therapy.

Adult↗
PubMed1990

A study on primiparous sows of the ability to show standing oestrus and to ovulate after weaning. Influences of loss of body weight and backfat during lactation and of litter size, litter weight gain and season.

The ability to show standing oestrus and to ovulate within 10 days of weaning was studied in 240 purebred Swedish Yorkshire primiparous sows, fed according to a conventional feeding regime during lactation. The sows were weighted and backfat depth was recorded at farrowing and at weaning. Oestrus control was performed daily and blood samples for determination of plasma progesterone were drawn regularly in 205 sows. The distribution among the sows of the first standing oestrus after weaning had 2 peaks. The first peak occurred within 10 days of weaning and the second 24-30 days after weaning. Twelve per cent of the sows ovulated without showing standing oestrus within 10 days of weaning and 4% had an anovulatory first oestrus within the same time. Significant differences in age at farrowing and in loss of weight and backfat during lactation were found between sows which both showed standing oestrus and ovulated within 10 days of weaning and sows which neither showed standing oestrus, nor ovulated within the same time. The season during which weaning occurred significantly influenced the ability to show standing oestrus and ovulate within 10 days of weaning. Among the sows which both showed standing oestrus and ovulated within 10 days of weaning, significant positive correlations were found between weight loss, litter size, litter weight gain and the interval from weaning to first standing oestrus.

Adipose Tissue↗