Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Ovulation Detection”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,135 records · Page 63Linked to original sources

Comparison of pregnancy rates achieved with frozen semen using two packaging methods.

The pregnancy rate achieved with frozen semen using two packaging methods was compared in two separate experiments. The sperm-rich fraction of the semen was collected and immediately extended in an egg-yolk based extender to a final concentration of 100 x 10(6) sperm/ml. Half of each ejaculate was packaged in 4.0-ml plastic straws and the other half in 10-to 12-ml flattened aluminum tubes. After detection of a 35-mm follicle, mares were inseminated daily until ovulation. Pregnancy was detected, and embryonic vesicle size was measured by ultrasonic echography Days 14 to 26 after ovulation. The one-cycle pregnancy rate achieved using both packaging methods was 50% overall (23 46 ), with 46% (12 26 ) and 55% (11 20 ) rates achieved, respectively, using straws and aluminum tubes. These rates were not significantly different.

Journal Article↗

Factors affecting temporal relationships between estrus and ovulation in commercial sow farms.

The main objective was to examine effects of season, parity, genotype, lactation length, and weaning-to-estrus interval on duration of estrus (DE) and onset of estrus-to-ovulation interval (EOI) in three sow farms. Detection of estrus and ovulation by the back-pressure test and transabdominal ultrasonography, respectively, were performed every 6 h from day 2-10 postweaning in 535 sows (approximately 89 per farm per season). The average weaning-to-estrus interval, DE, and EOI of the 501 sows that returned to estrus by day 10 postweaning were 4.6+/-0.1 days, 55.2+/-0.5 h, and 41.8+/-0.5 h, respectively. Farm x season (P<0.01), parity x season (P <0.05), and farm x weaning-to-estrus interval (P<0.05) interactions for DE and EOI were detected. Sows weaned in the summer had an 8 h longer (P<0.001) DE and EOI than those weaned in the spring on farms 1 and 3. On farm 2 however, DE and EOI did not differ (P=0.09) in sows weaned in summer versus spring. On each farm, parity 3 and > or =4 sows had a 4.5 h longer (P<0.05) DE and EOI than parity 1 and 2 sows in the summer, but there were no differences (P>0.11) in DE or EOI among parity classes in the spring. There was a linear decrease of DE (P<0.001) and EOI (P<0.05) as weaning-to-estrus interval increased from the 3 to the > or =7 day class on each farm. However, the range of weaning-to-estrus interval that exhibited a stepwise decrease of DE and EOI was narrower on farm 1 (3-5 days) than farms 2 and 3 (3-6 days). Only farms 1 and 3 had multiple genotypes. Genotype did not affect (P>0.14) DE on either farm, but the EOI of genotype B was 4 h shorter (P<0.05) than genotype C on farm 1. On each farm, DE decreased linearly (P<0.01) as lactation length increased from < or =13 to > or =20 days. In general, factors that affected EOI also affected (P<0.05) the percentage of inseminations that occurred within 24 h pre- to 3h post-ovulation. These data indicate that factors other than weaning-to-estrus interval, such as season and parity, can significantly alter DE and EOI. However, the effects of season and weaning-to-estrus interval on DE and EOI can be inconsistent among different farms.

Animal Husbandry↗

Relationship between size of the ovulatory follicle and pregnancy success in beef heifers.

Previous research indicated that the size of the ovulatory follicle at the time of insemination significantly influenced pregnancy rates and embryonic/fetal mortality after fixed-timed AI in postpartum cows, but no effect on pregnancy rates was detected when cows ovulated spontaneously. Our objective was to evaluate relationships of fertility and embryonic/fetal mortality with preovulatory follicle size and circulating concentrations of estradiol after induced or spontaneous ovulation in beef heifers. Heifers were inseminated in 1 of 2 breeding groups: (1) timed insemination after an estrous synchronization and induced ovulation protocol (TAI n = 98); or (2) AI approximately 12 h after detection in standing estrus by electronic mount detectors during a 23-d breeding season (spontaneous ovulation; n = 110). Ovulatory follicle size at time of AI and pregnancy status 27, 41, 55, and 68 d after timed AI (d 0) were determined by transrectal ultrasonography. Only 6 heifers experienced late embryonic or early fetal mortality. Interactions between breeding groups and follicle size did not affect pregnancy rate (P = 0.13). Pooled across breeding groups, logistic regression of pregnancy rate on follicle size was curvilinear (P < 0.01) and indicated a predicted maximum pregnancy rate of 68.0 +/- 4.9% at a follicle size of 12.8 mm. Ovulation of follicles < 10.7 mm or > 15.7 mm was less likely (P < 0.05) to support pregnancy than follicles that were 12.8 mm. Ovulatory follicles < 10.7 mm were more prevalent (28% of heifers) than ovulatory follicles > 15.7 mm (4%). Heifers exhibiting standing estrus within 24 h of timed AI had greater (P < 0.01) follicle diameter (12.2 +/- 0.2 mm vs. 11.1 +/- 0.3 mm) and concentrations of estradiol (9.9 +/- 0.6 vs. 6.6 +/- 0.7) and pregnancy rates (63% vs. 20%) than contemporaries that did not exhibit behavioral estrus. However, when differences in ovulatory follicle size were accounted for, pregnancy rates were independent of expression of behavioral estrus or circulating concentration of estradiol. Therefore, the effects of serum concentrations of estradiol and behavioral estrus on pregnancy rate appear to be mediated through ovulatory follicle size, and management practices that optimize ovulatory follicle size may improve fertility.

Animals↗

Recognition of ovulatory/anovulatory cycle pattern in adolescents by mucus self-detection.

The high frequency of anovulation during adolescence raises the question of whether a method for the recognition of ovulation by self-detection of cervical mucus patterns is useful in teenagers. We performed a secondary analysis of 1049 completely recorded cycles of 235 teen women 15-17 years of age with a gynecologic age from less than 1 to 7 years. These subjects had learned to monitor their fertility patterns using the Billings Ovulation Method. The cycles were analyzed by the length of the mucus and luteal phases and recorded "peak symptom." Ovulatory cycles were grouped by the length of the luteal phase, short (4-8 days) and average (8-18 days), and plotted against gynecologic age. The frequency of anovulatory cycles was comparable to Vollman's age-stratified monophasic cycle groups. Ovulatory patterns were found at gynecologic ages of 1 year, 49%; 2 years, 60%; 3 years, 72%; 4 years, 61%; 5 years, 86%; and 6 years, 71%. The study proved that teen-age women can distinguish patterns of ovulation and anovulation by self-detection of cervical mucus.

Adolescent↗

Ovulation prediction by monitoring salivary and vaginal electrical resistance with the PEAK Ovulation Predictor.

We investigated the ability of the PEAK Ovulation Predictor to predict the expected date of ovulation in 21 infertile, spontaneously ovulating women. A nonsignificant correlation (R = 0.15; P = .51) existed between the predicted date of ovulation and the day of the serum LH peak. A moderately strong correlation (R = 0.61; P less than .01) was observed between the day of the salivary electrical resistance peak and that of the serum LH peak. However, the serum LH peak occurred between 4-9 days after an identified peak in salivary electrical resistance. Twice-daily urine LH testing correlated strongly with both the serum LH peak (R = 0.93; P = .0001) and the ultrasound-detected day of ovulation (R = 0.81; P = .0001). A statistically significant peak in the mean salivary or vaginal electrical resistance on a particular day relative to the day of the serum LH peak could not be demonstrated. When identified, the nadir in vaginal electrical resistance occurred no earlier than 2 days before the serum LH peak and thus may mark the endpoint of the fertile period for natural family planning methods. We conclude that, whereas the PEAK Ovulation Predictor is of little value in accurately predicting ovulation, measurements of salivary and vaginal electrical resistance may be helpful in timing inseminations. However, for detection of the serum LH surge, twice-daily urine LH testing demonstrated a stronger correlation and narrower frequency distribution than did those determinations based on electrical resistance.

Adult↗

First cell cycle of zygotes of the mouse derived from oocytes aged postovulation in vivo and fertilized in vivo.

This paper describes an analysis of the first cell cycle of mouse oocytes aged postovulation and fertilized in vivo. For this purpose, we developed a procedure for inducing ovulation in vivo that allows accurate timing of ovulation. The method is based on a luteinizing hormone (LH)-releasing hormone (LHRH) administration at proestrus. This ovulation procedure had no detectable effect on the rate of ovulation or postimplantation embryonic death. We used this method of ovulation induction in an analysis of the separate stages of the first cell cycle of in vivo fertilized postovulation aged oocytes. All stages assessed were shorter in aged oocytes (12 hr postovulation) than in zygotes from unaged oocytes (1 hr postovulation): 1) the time interval between insemination and penetration of the aged oocytes was 1.5 hr shorter than the time interval of the unaged oocytes; 2) pronuclear formation in the fertilized aged oocytes was somewhat quicker than pronuclear formation in fertilized unaged oocytes; 3) in zygotes from aged oocytes, the time between formation of pronuclei and the pronuclear membrane breakdown was 1 hr shorter than in zygotes from unaged oocytes; 4) the first cleavage division was 3 hr advanced in zygotes from aged oocytes compared with the moment of the first cleavage division in zygotes from unaged oocytes. We also determined the glutathione (GSH) content of unaged and aged oocytes to investigate a possible relationship between the rate of pronuclear formation and GSH. The level of GSH was two times lower in oocytes aged postovulation for 12 hr than in unaged oocytes.2+ level of GSH in fertilized, unaged oocytes was half that in

Animals↗

Gonadotropin suppression for the treatment of karyotypically normal spontaneous premature ovarian failure: a controlled trial.

OBJECTIVE: To determine if gonadotropin suppression improves ovarian follicle function or ovulation rates in patients with karyotypically normal spontaneous premature ovarian failure. DESIGN: Prospective, double-blind, placebo-controlled, crossover trial. SETTING: Tertiary care research institution. INTERVENTIONS: Two intervention phases lasting 4 months each: one placebo phase, and one treatment phase during which each patient received daily subcutaneous injections of 300 micrograms of the gonadotropin-releasing hormone agonist (GnRH-a) deslorelin. During both phases, patients took a standardized estrogen (E) replacement regimen. PATIENTS, PARTICIPANTS: Twenty-six patients with karyotypically normal spontaneous premature ovarian failure ranging in age from 18 to 39 years. MAIN OUTCOME MEASURES: We measured serum estradiol (E2) and progesterone (P) levels weekly during the 2 months after each intervention. We defined a serum E2 greater than 50 pg/mL (184 pmol/L) as evidence for ovarian follicle function and a serum P greater than 3.0 ng/mL (9.5 nmol/L) as evidence for ovulation. RESULTS: The GnRH-a therapy did not significantly enhance recovery of ovarian follicle function or the chance of ovulation. The power to detect a 40% and a 33% ovulation success rate with therapy was 0.95 and 0.83, respectively. We found evidence for ovarian follicle function in 11 of 23 women (48%), and 4 women (17%) ovulated. CONCLUSIONS: Patients with karyotypically normal spontaneous premature ovarian failure treated with E replacement did not benefit from the additional gonadotropin suppression achieved with GnRH-a. Because these patients have a significant possibility of spontaneous remission, attempts to induce ovulation should be limited to controlled trials designed to determine safety and effectiveness.

Adult↗

Ovarian dynamics, serum estradiol and progesterone concentrations during the interovulatory interval in goats.

Ovarian changes determined by daily transrectal ultrasonic scanning, and its correlation with serum progesterone (P4) and estradiol (E2) concentrations were studied in seven cyclic Saanen goats. Estrous cycles were synchronized with 2 injections of a PGF2 alpha analogue 9 d apart. All follicles > or = 2 mm in diameter and CL were measured each day. One goat showed a longer interestrous interval, associated with development of a cystic-luteinized structure. The mean interovulatory interval for the other 6 goats was 20.8 +/- 0.4 d. The incidence of goats with 4, 3, and 2 follicular waves was 3, 1 and 2 respectively; follicular waves emerged on Days 0.5 +/- 0.6, 7.2 +/- 0.7, 10.7 +/- 0.5 and 13.7 +/- 0.8 for Wave 1, 2, 3 and the Ovulatory wave, respectively. The largest follicle of Wave 2 was smaller (4.9 +/- 0.1 mm) than the largest follicles of Wave 3 (6.2 +/- 0.1 mm; P < or = 0.01) and of the Ovulatory wave (7.0 +/- 0.5 mm; P < or = 0.01), and tended to be smaller than the largest follicle of Wave 1 (6.3 +/- 0.6 mm; P < or = 0.09). Interval between emergence of Wave 1 and Wave 2 was longer than interval between emergence of Wave 2 and Wave 3 (7.3 +/- 0.9 d vs 4.0 +/- 0.4 d; P < or = 0.01), and between Wave 3 and the Ovulatory wave (3.8 +/- 1.1 d; P < or = 0.05). Two days before ovulation, the diameter of the ovulatory follicle was larger (P < or = 0.01) than the first subordinate follicle. Serum E2 concentrations increased from the day of ovulation (2.7 +/- 0.3 pg/mL) to Day 2 (7.6 +/- 0.9 pg/mL; P < or = 0.01), associated with the early-mid growing phase of the largest follicle of Wave 1, and then decreased to basal levels on Day 5 (P < or = 0.01) and peaked again (16.5 +/- 2.4 pg/mL) 2 d before ovulation. The CL were detected ultrasonically on Day 3 post ovulation and attained a mean maximum diameter of 13.5 +/- 0.8 mm between Days 8 and 14. The following characteristics were observed: 1) ovarian follicular development in goats is wave-like; 2) increased P4 concentrations may be promoting follicular wave turnover; 3) it is suggested that the presence of follicular dominance and the production of E2 are different among waves. While in Wave 1 and in the Ovulatory wave, follicular dominance is present and production of E2 is consistent, no changes in serum E2 concentrations were found in other stages of the interovulatory interval. In the intervening waves, no indicators of follicular dominance could be firmly documented.

Animals↗

Simple or repeated induction of superovulation: a study on ovulation rates and microvessel corrosion casts in ovaries of golden hamsters.

Repeatedly stimulated ovaries are reported to decrease the ovulation rate. One cause among others might be that the microvascular bed has been insufficiently developed. Therefore, 30-day-old golden hamsters were superovulated either once or repeatedly. At the light microscopic level, the ovulation rate in serially sectioned ovaries was indirectly determined by the occurrence of corpora lutea and of abnormal follicle rupture with oocyte release into the cortical stroma (IOR). For the study with scanning electron microscopy (SEM), the microvascular bed of the ovaries was cast with a polyester resin, and the corrosion casts of mature follicles observed. The histological sections of once-stimulated ovaries showed a large number of corpora lutea and IOR follicles. This indicated hyperovulation. In corrosion casts of once-stimulated ovaries, large-sized antral follicles with two layers of a dense capillary meshwork were observed. Capillary sprouts were aligned around the antrum 0 to 12 h after administration of human chorionic gonadotrophin (hCG), and these radiated towards the center of the antrum after 12 to 36 h had elapsed. The ovulation site was recognized at the follicle apex by three similarly sized structures which were either a sinusoid, an oocyte replica, or an opening. Repeatedly stimulated ovaries produced a low number of corpora lutea and almost no IOR follicles. This was judged as hypoovulation. The microvessels of mature follicles were reduced in number and incompletely cast. Widespread resin leakages were conspicuous in the follicle wall 36 h after hCG injection, but the capillary sprouts radiated towards the center of the antrum. No ovulation site was detectable. It is concluded, that capillary sprouts are induced before luteinization. The ovulation site is indicated by particular changes in its microvascular bed. An insufficiently developed microvascular bed may be responsible for hypoovulation in repeatedly stimulated ovaries.

Animals↗

Effect of ovarian cysts detected on the beginning day of ovulation induction to the success rates in ART cycles.

AIM: In the present study, we examined the outcome of assisted reproductive technology cycles in patients with or without baseline ovarian cysts following gonadotrophin-releasing hormone analogs administration. MATERIALS AND METHODS: Three-hundred and fifty-six patients who had undergone assisted reproductive technology treatment were enrolled in the study. The patients, all of who had undergone cyst aspiration prior to ovarian stimulation, were grouped into two groups according to the absence or presence of ovarian cysts. These two groups were compared on the basis of the clinical pregnancy rates, the baseline E2 levels, the total follicle stimulating hormone ampules used, the total number of days of induction, the maximum E2 levels, the number of oocytes retrieved, the fertilization rates and the number of embryos available for transfer per controlled ovarian hyperstimulation cycle. RESULTS: The number of ampules used for induction was significantly higher in the cyst group 37.2 +/- 13.0, 32.1 +/- 11.7, respectively, (P = 0.001). The number of total induction days was also longer in the cyst group 9.7 +/- 2.2, 8.9 +/- 1.6, respectively, (P = 0.001). There was no difference between the mean E2 levels measured on the human chorionic gonadotropin administration days (P = 0.339). There was also no difference in terms of the number of oocyte retrieved (P = 0.846). The number of embryos transferred did not differ statistically between the groups (P = 0.233). Finally, there was no significant difference between the groups according to the clinical pregnancy rates 25.3%, 30.7%, respectively, (P = 0.218). CONCLUSION: Baseline ovarian cysts have a negative impact on the quality of ovarian hyperstimulation procedure; however, they have no negative effect on the pregnancy rates in IVF cycles.

Adult↗

Use of estradiol cypionate in a presynchronized timed artificial insemination program for lactating dairy cattle.

Experiment 1 evaluated pregnancy rates when estradiol cypionate (ECP) was used to induce ovulation as part of a timed artificial insemination (TAI) protocol in comparison to Ovsynch for lactating dairy cows in Florida (n = 371) and Texas (n = 321). Cows were presynchronized with two injections of PGF2, (25 mg, im) given 14 d apart with TAI protocols beginning 14 d after the second injection of PGF20. The TAI protocols consisted of an injection of GnRH (100 microg, im) followed by PGF2alpha 7 d later. Then, cows either received an injection of GnRH (Treatment I, Ovsynch) at 48 h after PGF2alpha and inseminated 16 to 24 h later or received an injection of ECP (1 mg, i.m.) at 24 h after PGF2alpha, (Treatment II; Heatsynch) and inseminated 48 h later. In Florida, pregnancy rates after TAI were 37.1 +/- 5.8% for Ovsynch compared with 35.1 +/- 5.0% for Heatsynch. In Texas, pregnancy rates were 28.2 +/- 3.6% for Ovsynch and 29.0 +/- 3.5% for Heatsynch. Overall pregnancy rates did not differ between Ovsynch and Heatsynch treatments. In Experiment 2, estrus and ovulation times were determined in lactating dairy cows submitted to the Heatsynch protocol. Frequencies of detected estrus and ovulation after ECP were 75.7% (28/37) and 86.5% (32/37), respectively. Mean intervals to ovulation were 55.4 +/- 2.7 h (n = 32) after ECP and 27.5 +/- 1.1 h (n = 27) after onset of estrus. Estrus occurred at 29.0 +/- 1.8 h (n = 28) after ECP. It is recommended that any cow detected in estrus by 24 h after ECP injection be inseminated at 24 h and all remaining cows be inseminated at 48 h because 75% (n = 24/32) of the ovulations occurred between > or = 48 h to < or = 72 h after ECP. Synchronization of ovulation and subsequent fertility indicated that estradiol cypionate could be used to induce ovulation for successful timed insemination.

Animals↗

Improving the reproductive efficiency by zoo-technical methods at a dairy farm.

This trial was conducted on a Hungarian dairy farm between July 2001 and December 2004. The objective of this work was to improve the reproductive efficiency with relatively high milk production. At the beginning of this trial blood and fodder samples were taken for checking the metabolic status of the animals in order to determine their health condition. The nutritive value of the daily ration for all groups met with the requirements of the Hungarian National Standard and almost all serum metabolic parameters differed between the milking and pregnant animals. Early pregnancy detection (by ultrasound) and ovulation synchronizing methods were introduced to optimize reproductive performance. The oestrus cycle was also checked by ultrasound and open cows were treated by the appropriate method in order to inseminate them as soon as possible. Efficiency of artificial insemination (AI) followed by a single prostaglandin F2alpha (PGF2alpha) and Ovsynch treatment was similar (30.8% and 29%) and less effective than AI after natural heat detection (37.1%). Provsynch (Pre-synch followed by Ovsynch) was the most effective ovulation synchronization method (conception rate=42.6%; p<0.01). Although milk production increased between 2002 and 2004 by approximately 600 kg per cow, the calving period decreased by 20 days and the number of AIs per pregnancy was also improved (0.8 AI per conception). These findings are really beneficial economically because the decrease in the calving interval returns profit for the dairy farms; one open day costs euro2.5/cow. Economical analysis showed a high profit ratio from the reproductive 'investment' on this farm. Every invested euro yielded approximately euro10.

Animal Feed↗

Effects of boar contact and housing conditions on estrus expression in weaned sows.

Our objective was to study the effects of housing conditions and the amount of boar contact in a protocol for estrus detection on estrus detection rate, timing of onset of estrus, duration of estrus, and timing of ovulation. After weaning, 130 multiparous sows were assigned to three treatments: HI, in which 52 sows were housed individually in crates and received a high amount of boar contact during estrus detection; HG, in which 52 sows were housed in groups and received a high amount of boar contact; and NI, in which 26 sows were housed individually in crates and received a normal amount of boar contact. Estrus detection was performed every 8 h. For each treatment, the standing response to three levels of stimuli was recorded: a back pressure test (BPT) by a man (man-estrus), presence of a teaser boar (spontaneous-estrus), and BPT in the presence of a teaser boar (boar-estrus). In addition, for HI and HG, the standing response to a fourth level of stimuli was recorded: BPT in a detection-mating area, surrounded by four boar pens (DMA-estrus). To detect ovulation, ultrasonography was performed every 4 h during estrus. Of 117 sows that ovulated, 46% showed man-estrus, 56% spontaneous-estrus, 90% boar-estrus, and 97% DMA-estrus. Mean onset of man-estrus was 107 h (SD 26) after weaning, of spontaneous-estrus was 106 h (SD 22) after weaning, of boar-estrus was 99 h (SD 21) after weaning, and of DMA-estrus was 93 h (SD 22) after weaning. Duration of man-estrus was 22 h (SD 14), of spontaneous-estrus was 29 h (SD 16), of boar-estrus was 42 h (SD 20), and of DMA-estrus was 55 h (SD 18). The high amount of boar contact reduced the number of sows showing man-estrus (P < .05; 41% for HG and HI vs 68% for NI) and reduced duration of boar-estrus (P < .05; 43 h for HG and HI vs 52 h for NI). Duration of DMA-estrus for HG and HI was similar to duration of boar-estrus for NI. Onset of estrus and timing of ovulation were not affected by amount of boar contact. Group housing did not affect detection rate and duration of estrus, but it did postpone average onset of estrus by 10 h, paralleled by a postponement of ovulation. In conclusion, estrus expression is similar at the highest level of stimuli in different protocols for estrus detection. Including higher levels of stimuli in a protocol reduces estrus expression at lower levels of stimuli. This reduction indicates adaptation of sows to a given protocol for estrus detection. Group housing can delay ovulation and related behavioral estrus.

Animals↗

Disappearance of the ovulation stigma in baboons (Papio anubis, Papio cynocephalus) as determined by serial laparoscopies during the luteal phase.

OBJECTIVE: To investigate how long an ovulation stigma remains visible as determined by serial laparoscopies performed during the luteal phase in baboons. SUBJECTS AND SETTING: Sixteen female baboons with a normal pelvis (n = 6) and with endometriosis (n = 10) housed at the Institute of Primate Research, Nairobi, Kenya. INTERVENTIONS: Fifty-six laparoscopies were carried out before ovulation (n = 7) and serially during the luteal phase (n = 49; 3 +/- 1 per baboon): 1 to 2 days (n = 2), 4 to 5 days (n = 15), 8 to 9 days (n = 11), 12 to 13 days (n = 12), and 16 to 17 days (n = 9) after ovulation. MAIN OUTCOME MEASURE: During each laparoscopy the ovaries were screened systematically for the presence and size of an ovulation stigma and/or corpus luteum (CL). RESULTS: When the laparoscopy was done within 5 days after ovulation, a fresh ovulation stigma was observed in all nine baboons with a normal pelvis or minimal endometriosis, but only in four of seven animals with mild to severe disease. If a fresh ovulation stigma had been observed within 5 days after ovulation (n = 13), it gradually became smaller but remained visible 8 to 9 days after ovulation in 91%, at 12 to 13 days after ovulation in 75%, and at 16 to 17 days after ovulation in 50% of the primates. CONCLUSION: If a fresh ovulation stigma was observed in baboons within 5 days after ovulation, it diminished in size but remained visible up to 8, 12, and 16 days after ovulation in 91%, 75%, and 50% of animals, respectively. Therefore, diagnostic laparoscopies for the detection of an ovulation stigma in baboons should be performed in the early luteal phase.

Animals↗

Gonadotropin-releasing hormone and prostaglandin F2 alpha for postpartum dairy cows: estrous, ovulation, and fertility traits.

A study of 234 Holstein cows was conducted to determine if early postpartum treatments of gonadotropin-releasing hormone, prostaglandin F2 alpha, or both would alter frequency and occurrence of estrus and ovulation as well as subsequent fertility. Cows in groups 1 and 2 received gonadotropin-releasing hormone (200 micrograms) between 10 and 14 d postpartum, and cows in groups 3 and 4 received saline. Ten days later, cows in groups 2 and 3 received prostaglandin F2 alpha (25 mg), and cows in groups 1 and 4 received saline. Treatment with gonadotropin-releasing hormone reduced intervals to first ovulation and first detected estrus as well as increasing the proportion of cows with three or more ovulations before first service from 57% for saline-treated controls to 83%. Treatment with prostaglandin F2 alpha reduced intervals to second and third ovulation and shortened the first estrous cycle. Treatments for cows in groups 1 and 3 increased the proportion of cows having estrous cycles of normal duration. Interval from calving to conception was reduced by 43 to 48 d for cows with an abnormal puerperium treated with either gonadotropin-releasing hormone or prostaglandin F2 alpha compared with controls (group 4) and by 27 to 29 d overall in all cows in groups 1 and 3. Cows with normal or abnormal puerperium in groups 1 and 3 required 26 to 41% fewer services per conception than controls. We conclude that treatments of gonadotropin releasing hormone or prostaglandin F2 alpha, but not the treatment combination, improved fertility of dairy cows, especially those that experienced puerperal problems.

Animals↗

Plasma steroid and corticosteroid levels in female pacu Piaractus mesopotamicus, Teleostei-Characidae.

We report the plasma levels of estradiol-17 beta (E2), testosterone (T), 17 alpha-20 beta-dihydroxy-4-pregnen-3-one (17-20P), and cortisol (F) in female pacu during the reproductive cycle (N = 44) and in females induced to ovulate with an analogue of luteinizing hormone releasing hormone (LHRHa; 10 micrograms/kg) (N = 24). The plasma hormone levels were determined by validated radioimmunoassays. Females sampled during the reproductive cycle were grouped into 4 gonadal stages: resting, early maturation, advanced maturation and regression. The calculated gonadosomatic index varied from 0.5 +/- 0.1% in resting stage to 8.1 +/- 0.6% in advanced maturation stage. The E2 and T values were highest during the early maturation stage (E2 = 2172 +/- 7.1 pg/ml; T = 412 +/- 58 pg/ml) and the F values were highest during the advanced maturation stage (132 +/- 5 ng/ml). Females induced to ovulate by LHRHa injection were sampled at 0.6, and 12 h after injection of LHRHa. Two additional groups were sampled at ovulation and 24 h after ovulation. The E2 values were highest at 6 h (2917 +/- 65 pg/ml). The T and F values were highest at ovulation (T = 3498 +/- 77 pg/ml; F = 387 +/- 16 ng/ml) and 17-20P was detected only at ovulation (2163 +/- 80 pg/ml).

Analysis of Variance↗

RNA synthesis in preovulatory mouse oocytes.

RNA synthesis, previously shown to take place during oocyte growth, has been demonstrated throughout the growth-quiescent period preceding ovulation of the mouse oocyte. In the final 7-day preovulatory period, the level of incorporation of (5,6-3H)uridine into ovulated oocytes decreased as the interval between exposure to precursor and ovulation decreased; significant incorporation was detectable within 2 days before ovulation. Analysis of the frequency and density of label in ovarian oocytes at successive stages of meiosis in relation to the interval between adminstration of labeled precursor and collection of oocytes revealed that RNA synthesis continues up to within 2 h before GVBD.

Animals↗

Comparison of equine pituitary extract and follicle stimulating hormone for superovulating mares.

Sixty light-horse, nonlactating mares were used to compare the efficacy of equine pituitary extract versus follicle stimulating hormone (FSH-P) for inducing multiple ovulations. On Day 12 of diestrus, mares were assigned to receive 1) no treatment, controls; 2) subcutaneous injections of 750 Fevold rat units of equine pituitary extract once daily; or 3) intramuscular injection of 150 mg of FSH-P twice daily. Ultrasound was used twice daily to visualize follicular changes and ovulation. For mares in Groups 2 and 3, treatment was initiated when two or more follicles > 20 mm were detected, and it continued until all large follicles (> 30 mm) had ovulated or regressed. Five milligrams of prostaglandin F(2)alpha (PGF(2)) were administered to mares in Groups 2 and 3 on the first day of treatment. Human chorionic gonadotropin (3,300 IU) was given to all groups of mares during estrus when a 35-mm follicle was detected. Ovulation rate was greater (P < 0.05) for mares treated with pituitary extract (2.2) compared to FSH-P treatment (1.6) or no treatment (1.0). Thirteen of 18 mares treated with the extract had more than one ovulation versus only four of nine FSH-treated mares. Mares in the pituitary extract group were given injections for an average of 6.4 d compared to 6.8 d (13.7 injections) for FSH-treated mares. Intervals to estrus and ovulation from initial injection of extract were 2.9, 7.6; and 2.6, 9.2 d for FSH-treated mares. The mean number of medium-sized follicles (25 to 30 mm) was greater (P < 0.05) in extract-treated mares compared to the FSH-treated mares. Both extract and FSH increased (P < 0.05) the number of follicles > 30 mm and the size of the second largest follicle 1 and 2 d prior to ovulation when compared to controls. Overall, mares with multiple ovulations had more (P < 0.05) follicles 25 to 30 mm and > 30 mm on Day -6 through -1 (Day 0 = day of ovulation) than single ovulating mares. Those mares that had multiple ovulations had less (P < 0.05) size difference between the largest and second largest follicle when compared to single ovulating mares. In summary, FSH-P at the one dose studied was less effective than equine pituitary extract in inducing follicular activity and multiple ovulation in the mare.

Journal Article↗