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 1,225 records · Page 68Linked to original sources

Serum concentration of placental proteins in non-pregnant and pregnant subjects.

Chorionic gonadotrophin (hCG) and Schwangerschaftsprotein 1 (SP1) were measured in 35 menstrual cycles in 20 women. During the follicular phase, 3 samples were positive for hCG and two of these were also positive for SP1. All these positives occurred on the day of ovulation or immediately before. In the luteal phase 25 specimens showed both hCG and SP1 and two showed only SP1, the positive results occurring 3-15 days after ovulation. The placental proteins were also measured in a further eight women who became pregnant. The pattern in these was quite different. The first positives were detected 8 days after ovulation and by 12 days all the subjects were positive for both proteins. Thereafter both proteins increased sharply in concentration. A group of 139 subjects who, on biological grounds, could not have conceived, showed no positive results.

Adolescent↗

A comparison of 1- and 2-cell ova production by F2 50% Meishan versus F1 White line gilts.

The objective of this study was to compare recovery of pronuclear and 2-cell ova from F2 50% Meishan (MX) gilts versus F1 White line (L42) gilts. Sexually mature MX and L42 gilts were allocated across 2 treatments: Super (MX:n=9; L42:n=10) and Control (MX:n=6; L42:n=5) in a 2 x 2 factorial experiment. Allyl trenbolone (AT) was used to synchronize estrus in all gilts. Super gilts were given pregnant mare serum gonadotropin (PMSG: 1250 IU) at 24 h after AT withdrawal. Eighty-five hours after PMSG administration, all Super gilts received 750 IU of human chorionic gonadotropin (hCG). Super gilts which exhibited estrus within 24 h of hCG administration (MX-Super: n=6; L42-Super: n=5) and all Control gilts were bred naturally to Line 3 boars at 12 and 24 hours after the onset of estrus. Ova were recovered from Super gilts between 60 and 64 h after hCG and Control gilts at 48 h after the onset of estrus. All 1- and 2-cell ova were centrifuged at 15000 x g and observed using differential interference contrast microscopy. The mean ovulation rate was greater (P<0.05) for both MX-Super and L42-Super gilts in comparison to their respective Control groups. No differences were detected in the mean ovulation rate (P>0.38) or the mean number of 1- and 2-cell ova recovered (P>0.50) between MX-Super and L42-Super gilts. The proportion of 1- and 2-cell ova which exhibited visible pronuclei or nuclei was also similar among MX-SUPER and L42-SUPER gilts. This study demonstrates that MX gilts respond/perform comparably to L42 gilts with respect to estrus synchronization, superovulation, ova yield, and the ease of visibility of pronuclei or nuclei in the ova.

Journal Article↗

Early implantation stages in the marmoset monkey (Callithrix jacchus).

The morphology of the initial stages of implantation in the marmoset monkey (Callithrix jacchus) was studied by obtaining embryos and associated endometrium at timed intervals after ovulation. Estrus cycles were detected by measuring daily levels of plasma progesterone. Following a short follicular phase, circulating levels of progesterone above 20 ng/ml were taken as representing day 1 after ovulation. On this basis, single, twin, and triplet embryos were recovered from six perfused-fixed females on days 13, 16, 19, 23, and 29 after ovulation and prepared in resin for light microscopy. Early implantation stages, 13 and 16 days after ovulation, were characterized by the intrusion of syncytial trophoblast between epithelial cells of the endometrium with minimal cellular damage. Some hyperplasia of epithelium at the margin of the implantation site was evident. The consolidation of the initial attachment was achieved by an increase in syncytial trophoblast underlying the inner cell mass of the embryo which rapidly surrounded and breached maternal capillaries. Although initially separate, the chorions of twin or triplet embryos started to fuse by day 19 after ovulation. This process was complete by day 29 such that embryos shared a common uterine exocoelom surrounded by continuous trophoblast. It was concluded that implantation in the marmoset monkey commenced on days 11-12.5 after ovulation and involved an intrusive mechanism. Although trophoblast penetration of endometrium was superficial, maternal capillaries were tapped at an early stage of implantation. The fusion of chorions of twins and triplets first occurred around day 19 after ovulation.

Animals↗

Two avian luteinizing hormone radioimmunoassay procedures compared by measurement of changes during the ovulatory cycle of turkey and broiler hens.

Two radioimmunoassay (RIA) procedures for measuring avian luteinizing hormone (LH) were compared using divided aliquots of plasma samples collected during the ovulatory cycles of turkey and broiler breeder hens in three separate experiments. The RIA systems compared were the homologous turkey LH assay Wentworth et al. (1976) and the homologous chicken LH assay of Follett et al. (1972). Both assays provided the same assessment of circulating LH changes. The preovulatory surge of LH was observed 6 hr before ovulation in turkeys and 4 hr before ovulation in chickens. In addition, both assays detected an increase in chicken LH after ovulation, followed by a gradual decline prior to the next preovulatory surge. The correlation between RIA were highly significant (P less than .001) in each experiment. The crossreaction of purified ostrich LH, FSH, and TSH and of the alpha and beta subunits of turkey LH was assessed in each assay system. Ostrich LH, FSH, and TSH crossreacted in the chicken LH assay in a dose-related manner: ostrich LH showed the highest activity. Only ostrich TSH produced a response in the turkey assay that was dose related. The alpha subunit, but not the beta subunit, of turkey LH was quite potent in the chicken LH RIA, but neither subunit competed as well as the native hormone in the turkey RIA. Thus, the two LH antisera recognize different portions of the LH molecule. The chicken antiserum apparently recognizes a site on the alpha subunit that may be at least partially masked in the FSH and TSH molecules. The turkey antiserum recognizes a site on the native LH molecule that is altered when the subunits are separated.

Animals↗

Ultrasound and endocrine evaluation of the ovarian response to PGF2alpha given at different stages of the luteal phase in ewes.

The purpose of this study was to evaluate the ovarian response of ewes to two treatments with PGF2alpha using transrectal ovarian ultrasonography and hormone measurements. Fifteen milligrams of PGF2alpha was given to six cyclic Western White Face (WWF) ewes early in the estrous cycle (Days 4 to 7) and to six late in the cycle (Days 10 to 12 after ovulation), and a second treatment was given 9 days after the first. Ultrasound scanning and blood sampling started 7 days prior to the first PGF2alpha treatment and ended 10 days (scanning) or 19 days (blood sampling) after the second PGF2alpha treatment, for both groups of ewes. Mean ovulation rate (2.6 +/- 0.7) did not differ significantly between the ewes first treated early or late in the cycle, or after the first or second treatments with PGF2alpha. The time from treatment to ovulation was longer in ewes first treated early (4.0 +/- 0.3 days) compared to late (2.8 +/- 0.4 days) in the cycle (P < 0.05). Both the number of ovulations (range: 0-7) and time from treatment to ovulation (range: 1-9 days) were highly variable. This variability appeared to be due to the extension of the life span of ovulating follicles that emerged prior to PGF2alpha administration and also ovulation of some follicles that emerged after treatment. When results for first and second treatments were pooled, the total number of follicles > 5 mm in diameter on the day of treatment that failed to ovulate in response to PGF2alpha was higher in ewes first treated early (0.8 +/- 0.2/ewe) compared to late (0.3 +/- 0.2/ewe) in the cycle (P < 0.05). The proportion of detected luteal structures relative to the number of ovulations was lower in ewes first treated early compared to late in the cycle (60 and 86%, respectively; P < 0.05). Disruption of ovulatory follicle dynamics and normal luteogenesis, and variability in the timing of ovulation after PGF2alpha treatments could all contribute to poor or variable fertility when prostaglandins are used for estrus synchronization.

Animals↗

Association of uterine edema with follicle waves around the onset of the breeding season in pony mares.

During spring transition, when estrus may be exhibited for prolonged periods, it is important for veterinarians and stud farm personnel to be able to predict whether a large follicle will ovulate or regress. It is thought that the presence of ultrasonically detectable uterine edema indicates that a follicle will ovulate, however, there is little evidence to support this. In the present study, 16 mares were regularly examined by transrectal ultrasonography to follow growth and regression of follicles from seasonal anestrus in February until second ovulation. Blood samples were collected daily for measurement of estradiol concentrations when a large ovarian follicle was present. Estrous-like uterine edema was detected during 7 of 11 (64%) anovulatory follicle waves, in 12 of 14 (86%) mares before their first ovulation, and in 100% of mares before their second ovulation. Uterine edema was first detected 43+/-6.7 days before first ovulation. Large anovulatory follicles tended to be present for longer periods of time than ovulatory follicles. Uterine edema was present for a significantly greater proportion of time in the presence of a large follicle at second ovulation than at first ovulation (P<0.05) or for anovulatory follicles (P<0.01). Peak plasma estradiol concentrations and mean plasma estradiol concentrations were significantly higher (P<0.001) when a dominant preovulatory follicle was present compared with a dominant anovulatory follicle, but there was no difference in estradiol concentrations between first and second ovulations. It was apparent, therefore, that uterine edema was not a reliable indicator of follicular steroidogenic competence, or of whether the follicle would ovulate.

Animals↗

Milk progesterone profiles in crossbred Brown Swiss x Nellore cattle following natural service.

Ovarian activity and estrous behaviour were monitored through milk progesterone determinations and twice daily visual observations in 70 crossbred Brown Swiss x Nellore cows following natural service. Whole milk samples were collected on the day of estrus (Day 1), Day 11, and every 5 d thereafter until the next estrus or pregnancy confirmation. Seventy percent of the cows behaved as expected, i.e. they showed a 19-to 25-d interval between estrus and the next ovulation, or they became pregnant. Estrous cycles of regular length (18 to 24 d) were found in 54% of the cases. Prolonged luteal phases (interval from estrus to next ovulation > 28 d) were found in 15.7% of cows. Short estrous cycles (interestrous interval < 18 d) were found in 7.1% of the cases. Periods of acyclicity (basal progesterone levels for periods >/= 15 d) were found in 5.8% of the cases, and one cow exhibited estrus while pregnant and had a high progesterone concentration. Cows with a prolonged luteal phase and those with a short estrous cycle had an interval between ovulations of 35.0 +/- 6.7 d (x +/- SD) and 9.6 +/- 3.1 d, respectively. Signs of estrus were not detected in 33.3% of the ovulations confirmed by progesterone determinations. Low conception rates, failures in estrus detection and a high frequency of abnormal postbreeding luteal phases were found.

Journal Article↗

Reduced dry periods and varying prepartum diets alter postpartum ovulation and reproductive measures.

There has been substantial recent interest in shortening dry periods; however, the effects of this management change on reproduction have not been adequately evaluated. Holstein cows (n = 58) were assigned in a randomized block design to 1 of 3 treatments: 1) traditional (T) dry period (approximately 56 d) in which cows were fed a low energy diet from 56 to 29 d prepartum followed by a moderate energy diet for 28 d; 2) shortened (S) dry period (approximately 28 d) in which cows were fed continuously a high energy diet; or 3) no planned (N) dry period in which cows were fed continuously a high energy diet. All cows received a high energy lactation diet after calving. Ovaries were evaluated by ultrasound and blood samples collected 3 times weekly beginning at d 6 or 7 postpartum until 7 d after second ovulation. Average days from calving until first detection of a 10-mm follicle were fewer in N (8.0 d) and S (8.9 d) than in T (10.5 d) cows. Time from calving to first ovulation was earlier in N (13.2 d) than in S (23.8 d) and T (31.9 d) cows. A greater percentage of follicles of the first follicular wave ovulated in N (89%; 16/18) than in T (42%; 8/19), with S (62%; 13/21) cows being intermediate. Double ovulation rate at the first ovulation was greater in T (61%) than N (16%), with S (35%) intermediate. No difference was detected in double ovulation rate at second ovulation (13/56). Number of cows with persistent corpus luteum (>30 d; 15/56) was not different among groups; however, short luteal phases were greater in N (28%; 5/18) than S (0%; 0/20) cows. Days to first artificial insemination were fewer in N (69.4 d) and S (68.0 d) than in T (75.0 d). First-service conception rate was greater in N (55%; 11/20) than in T (20%; 4/20), with S (26%; 6/23) cows being intermediate. Days open in pregnant cows were fewer in N (93.8 d) than in T (145.4 d), with S (121.2 d) cows being intermediate. Thus, shortening or eliminating the dry period leads to earlier postpartum ovulation and the results highlight the need for future large field studies to accurately evaluate the effect of dry period length on reproductive performance of lactating dairy cows.

Animals↗

[Prediction of ovulation by urinary LH surge].

To investigate the usefulness of a semi-quantitative assay of urinary luteinizing hormone (LH) for predicting ovulation, the relationship among urinary LH, serum LH, serum estradiol (E2) and ultrasonographic observations of follicles were examined in 32 infertile women (35 cycles) at spontaneous (7), clomiphene (13) or cyclofenil (3) induced or hMG (12) induced cycles. Their urine samples were collected 3 times a day for LH assay, starting from about the 10th cycle day or when follicles having a diameter of 10mm or more were detected to the day of ultrasonographical confirmation of follicle ruptures. In the morning on these days, blood was taken twice daily for LH and E2 determination at intervals of 30 min. In spontaneous cycles, urinary LH was (P < 0.001) correlated to a significant extent with the serum LH and E2 levels, and follicle rupture was observed 1.9 days after the urine LH surge. In contrast, there was no significant correlation between the urine LH and serum LH or E2 levels in the ovulation induced cycles. In addition, the period from urine LH positive to follicle rupture was significantly (P < 0.05) prolonged in those cycles compared with that in spontaneous cycles. These results suggested that the urine LH determination was good for predicting ovulation in spontaneous cycles, but it was also necessary to monitor the follicle sizes by ultrasonography in ovulation induced cycles.

Adult↗

Effect of follicular phase administration of mifepristone (RU486) on blastocyst implantation in the rhesus monkey.

In the present study our aim was to test two hypotheses: 1) inhibition of preovulatory phase progesterone action can inhibit or delay ovulation, and 2) inhibition of preovulatory phase progesterone action can inhibit postovulatory phase endometrial receptivity for blastocyst implantation. Female rhesus monkeys showing normal cycle lengths were randomly assigned to two groups: group 1 (n = 5) and group 2 (n = 7). The pretreatment cycles were monitored for ovulatory pattern and, in treatment cycles, females were allowed to cohabit with males from cycle days 6 to 28; group 1 animals received vehicle alone, and group 2 animals received mifepristone (RU486, subcutaneously), 1 mg/animal 3 consecutive cycle days (days 7, 8, and 9 for 26-day pretreatment cycle length; and days 8, 9, and 10 for 28-day pretreatment cycle length). Follicular phase mifepristone resulted in a delay of ovulation (p < 0.01) when compared with pooled data of pretreatment and treatment cycles of group 1 and pretreatment cycles of group 2. Despite delay of ovulation, there was only a 20% decrease in the incidence of pregnancy in group 2 as compared with that in group 1. However, a delay (p < 0.05) in the appearance of CG was noted in follicular phase mifepristone-treated cycles as compared with control treatment cycles. On the other hand, ovulation could not be detected in three monkeys in group 2; and, of these, two cycles were extended, but all three cycles were negative for CG. These results support earlier reports that follicular phase mifepristone can inhibit or disrupt follicular maturation, and delay ovulation. However, follicular phase mifepristone failed to inhibit implantation, because gonadal hormones, including progesterone, resume normal functions once ovulation takes place.

Animals↗

[Salivary LH as an ovulation indicator: on the value of autopalpation of the cervix uteri for the detection of fertile and infertile days of the cycle].

The validity of autopalpation of the cervix as an indicator of fertility has been studied in 115 cycles of 13 nulliparous and 13 parous women, aged 22 to 35 years and experienced in self-observation methods (SOM) of family planning. For this purpose, the reported cyclic changes of the cervix uteri (hard, closed and low positioned; soft, open and higher positioned or intermediate stages) have been compared with the salivary LH-peak as indicator of ovulation, the BBT-readings and cervical mucus quality. The study has confirmed that in principle it is possible to collect sufficiently reliable self observation data for family planning purposes by autopalpation of the cervix. Parous women detect the first preovulatory changes of the cervix earlier and more frequently than nulliparous. Nevertheless it is not possible for either group to determine the beginning of the fertile days in this way. The beginning of the postovulatory infertile phase, however, can be detected: if, in accordance with rising BBT, the cervix has returned to a hard and closed appearance for 4 days, this symptom signals infertility with the same high degree of accuracy as the third measurement of elevated BBT (BBT3). Thus a "rule of thumb" can be established, linking the beginning of postovulatory infertility to either the fourth day of the hard and closed cervix or to the evening of the day of BBT3, "whatever comes first". In this way, the beginning of the infertile phase could be recognized one to three days earlier by referring to the cervix in about 20% of the cycles.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

An ultrasonographic study of luteal function in breeds of sheep with different ovulation rates.

Development and demise of luteal structures were monitored using daily transrectal ultrasonography in 2 breeds of sheep differing in ovulation rates (nonprolific Western white-faced cross-bred, n = 12 and prolific pure-bred Finn sheep, n = 7), during 1 estrous cycle in the mid-breeding season. Jugular blood samples were collected once a day for radioimmunoassay (RIA) of progesterone. The mean diameter of ovulatory follicles was higher in Western white-faced than in Finn ewes (6.4 +/- 0.2 and 5.3 +/- 0.2 mm, respectively; P < 0.001). The mean volume of luteal structures was higher (P < 0.05) in Western white-faced compared with Finn sheep from Days 5 to 15 of the cycle (Day 0 = day of ovulation). This accounted for the higher (P < 0.05) total luteal volumes recorded in Western white-faced ewes on Day 7 and from Days 11 to 15, despite the higher ovulation rate in Finn ewes (2.7 +/- 0.3 and 1.7 +/- 0.2, respectively; P < 0.05). Mean serum progesterone concentrations were higher (P < 0.05) in Western white-faced than in Finn ewes from Days 4 to 14. Daily total luteal volumes were positively correlated with daily serum progesterone concentrations throughout the cycle in Finn sheep (r > or = 0.40, P < 0.02), and during luteal growth and regression (r > 0.60, P < or = 0.00001) but not during mid-cycle in white-faced ewes (r = 0.16; P = 0.22). During the growth of the corpora lutea (CL), luteal tissue volume increased faster (P < 0.05) than serum progesterone concentrations in both breeds of sheep. During luteolysis, the decrease in luteal volumes parallelled that in serum progesterone concentrations in Finn (P = 0.11) but not in Western white-faced ewes, where luteal volumes decreased more slowly (P = 0.02) in relation to progesterone secretion. Increased ovulation rate in prolific Finn ewes resulted in more but smaller CL, and lower serum progesterone levels compared with nonprolific Western white-faced ewes. We conclude that breed-specific mechanisms exist to control the formation of luteal tissue and progesterone secretion in cyclic ewes differing in prolificacy. The mechanisms may involve ovulation of Graafian follicles at different sizes and inhibitory paracrine effects of CL on co-existing CL.

Animals↗

[The ovarian response and conception rate in cows during experimental nitrate loading].

The effects of potassium nitrate were investigated on ovarian activity, especially on ovarian activity, especially on follicle ripening and ovulation, conception rate and progesterone levels in the milk of cows with cloprostenol-induced oestrus (Oestrophan Spofa) at a rate of 500 micrograms i.m. Potassium nitrate was administered at an amount of 150 g per head/day, and this amount increased by 50 g every other fortnight to the total rate of 300 g per head/day. In a group of 11 cows exposed to potassium nitrate load, clinical examination of ovaries on day 8 after oestrus revealed the presence of CL in seven cows (63.6%), persisting follicles in two cows, and two cows did not have any CL or follicles (Tab. I). After the first insemination three cows got in calf (27.3%), and after all inseminations it was 10 cows in total (90.9%) on average in 24.4 days after cloprostenol administration, with SP 96.7 days and insemination index 1.7. No ovulation disorders were found in the control group. All five cows got in calf after the first insemination in three days after cloprostenol administration with SP 61.5 days and insemination index 1.0 (Tab. II). The progesterone levels in milk were 22.3 and 21.1 ng/ml before the second administration of cloprostenol, 2.7 and 2.1 ng/ml in oestrus and at the time of A.I., and 16.6 in eight days after insemination in cows exposed to nitrate load, and finally 21.7 ng/ml in the control group (Tab. III). Ovulation disorders were easily detectable by a clinical check of ovaries on day 8 after oestrus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Gonadal expression of c-kit encoded at the W locus of the mouse.

Recently, it has been shown that the c-kit proto-oncogene is encoded at the white spotting (W) locus in mice. Mutations of this gene cause depletion of germ cells, some hematopoietic cells and melanocytes. In order to define further the role of c-kit in gametogenesis, we have examined its expression in late fetal and postnatal ovaries and in postnatal testis. By RNA blot analysis, c-kit transcripts were not detected in late fetal ovaries but appeared at birth. The relative amount reached a maximum in ovaries of juvenile mice, and decreased in adult ovaries. c-kit transcripts were present in increasing amounts in isolated primordial, growing and full-grown oocytes, as well as in ovulated eggs. Little was detected in early 2-cell embryos and none in blastocysts. In situ hybridization revealed c-kit transcripts in a few oocytes of late fetal ovaries and in all oocytes (from primordial to full-grown) in ovaries from juvenile and adult mice. Expression was also observed in ovarian interstitial tissue from 14 days of age onward. Using indirect immunofluorescence, the c-kit protein was detected on the surface of primordial, growing and full-grown oocytes, as well as on embryos at the 1- and 2-cell stages; little remained in blastocysts. In situ hybridization analysis of testes from mice of different ages demonstrated expression in spermatogonia from 6 days of age onward. Using information provided by determining the stage of the cycle of the seminiferous epithelium for a given tubule and by following the age dependence of labeling, it was concluded that the period of expression of c-kit extends from at least as early as type A2 spermatogonia through type B spermatogonia and into preleptotene spermatocytes. Leydig cells were labelled at all ages examined. The expression pattern in oocytes correlates most strongly with oocyte growth and in male germ cells with gonial proliferation.

Animals↗

Morphometry of ovarian structures by transrectal ultrasonography in Serrana goats.

The accuracy of transrectal real-time ultrasonography (RTU) scanning technique to detect ovarian structures (follicles and corpus luteum) of Serrana goats was compared to the data obtained by observation of ovarian sequential slices. This slicing technique (SLI) was considered as reference method. The laparoscopy and laparotomy techniques were also used for corpora lutea identification. For this purpose the ovaries of 14 females were observed, 7-8 days after ovulation, by transrectal ultrasonography followed by laparoscopic examination. Then ovaries were removed and studied by slicing. In the sliced sections of each ovary (n=28), follicles and corpus luteum (CL) were identified and counted. CL and follicular diameters were measured using a millimetre scale. The total number of follicles, counted by RTU, was significantly lower than that observed by SLI (P <0.01). This difference was mainly due to the under estimation of <2 mm follicles category. The correlation coefficient between category data obtained by RTU and SLI methods for the number of follicles > or =3 mm was high (r2=0.95, P <0.001), which highlights the use of UTR as a potential methodology to study the follicular dynamic of goats. There were no significant differences (P >0.05) between the average number (mean +/- S.D.) of corpus luteum identified per ovary by RTU (0.71 +/- 0.75), laparoscopy (0.58 +/- 0.71), laparotomy (0.67 +/- 0.76) or SLI (0.83 +/- 0.76) methods. The accuracy for the identification of ovulation, validated by CL detection on D7-D8 by SLI (100%), was 91.7%, 87.5% and 83.3% by RTU, laparotomy and laparoscopy, respectively. The negative predictive value of RTU, laparotomy and laparoscopy to verify the absence of a CL in the ovary was 81.8%, 75.0% and 69.2%, respectively. The specificity of all three methods for the CL identification was 100%. No significant differences (P >0.05) were found in the probability to detect the exact number of CL (0, 1 or 2) counted in each ovary between the RTU (87.5%), laparotomy (83.3%) and laparoscopy (75.0%) methods when compared with the reference method. The diameter of spherical CL could be estimated with reliability (r2=0.86; P <0.001). The real-time ultrasonographic scanning proved to be a highly accurate method for detection and measurement of several categories of follicles and CL size in Serrana goats. The results of the present study show that laparoscopy and RTU are similarly reliable techniques for CL detection. However, the RTU represents a non-traumatic technique with advantages to animal welfare both in experimental and reproductive evaluation of the size of ovarian structures.

Animals↗

Effect of insemination timing on the fertilizing capacity of frozen/thawed equine spermatozoa.

A breeding trial was conducted to evaluate the effect of insemination timing on the fertility of mares bred with frozen/thawed equine semen. One stallion and 60 reproductively sound, estrous-synchronized mares were included in the study. Mares were assigned to one of three groups (n = 20): 1) insemination with fresh semen every other day during estrus from detection of a 35-mm follicle until ovulation, 2) insemination with frozen/thawed semen every day during estrus from detection of a 35-mm follicle until ovulation or 3) insemination with frozen/thawed semen once, within 6 h after ovulation. Single-cycle 18-d pregnancy rates resulting from insemination with fresh semen (70%), preovulation insemination with frozen/thawed semen (60%) and postovulation insemination with frozen/thawed semen (55%) were not different (P > 0.05). Possibly, equivalent pregnancy rates could be achieved with frozen/thawed semen using either daily inseminations until ovulation occurs or frequent ovarian palpations with a single post-ovulation insemination. Further studies regarding the effect of insemination timing on stallion fertility are needed since the present investigation included only one stallion and a small number of mares.

Journal Article↗

Prediction of ovulation by urinary hormone measurements with the home use ClearPlan Fertility Monitor: comparison with transvaginal ultrasound scans and serum hormone measurements.

The timing of sexual intercourse in relation to ovulation strongly influences the chance of conception. Daily serum LH measurements or transvaginal ultrasonography are not practical to determine ovulation in consecutive cycles for an individual. A prospective study was initiated to test the home use performance of the ClearPlan Fertility Monitor (CPFM) in ovulation prediction compared with transvaginal ultrasonography and serum hormone measurements. A total of 53 women aged 18-39 years with a normal uterus and at least one ovary, cycle length between 21-42 days and not using medication which interferes with ovarian function contributed 150 cycles for analysis. One cycle was anovulatory and no LH surge, indicating peak fertility, was detected by the monitor. Of the remaining 149 cycles, 135 (90.6%) had a monitor LH surge and ultrasonographically confirmed ovulation. Ovulation was detected in 91.1% of cycles during the 2 days of CPFM peak fertility. Ovulation was observed in 51.1% of cycles 1 day and in 43.2% of cycles 2 days after the surge in serum LH. Ovulation never occurred before CPFM peak fertility or the serum LH surge day. CPFM can help women who desire pregnancy to time intercourse. It may also have potential as a diagnostic aid and for monitoring the treatment of infertility.

Adolescent↗

[Double ovulation in mares. Clinical, hormone analytical and sonographic studies].

108 mares with a total of 135 oestrous cycles were examined. 30% of the mares showed development of double follicles, found by palpation and ultrasonography. Eight cases of double ovulation, four of them synchronous and four asynchronous, were examined closely. These cases of double ovulation showed different growth and different development of the follicular wall. This occurred at the same time in cases of synchronous double ovulation whereas it differed in case of asynchronous double ovulation. The later ovulating follicle was still growing while the first one had already burst. With both forms of double ovulation an equal concentration of progesterone was detected in peripheral blood. On the day of ovulation the rate of progesterone was low (1 ng/ml blood plasma) and it first started rising from the day +1 on. Double follicles matured slower than single follicles. Mares with synchronous double ovulation showed the typical oestrus behavior. This behavior was less distinct after the first ovulation in mares with asynchronous double ovulation. All four mares with asynchronous and two mares with synchronous double ovulation became pregnant. Twins did not occur. A possible relationship between double ovulation and twin pregnancy is discussed.

Animals↗