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PubMed1992

The effect of follicle maturing drugs on side of ovulation in successive cycles.

Our previous study has demonstrated that ovulation in unstimulated cycles is random with an equal likelihood of ipsilateral or contralateral ovulation occurring in the following cycle. This study evaluated women taking ovulation-inducing drugs to see if the side of ovulation in the preceding cycle has an influence on the side of ovulation in the succeeding cycle. Ovulatory patterns in consecutive pairs of cycles in anovulatory women treated with ovulation-inducing drugs were evaluated through sonographic studies of follicular maturation. The results demonstrated that when unilateral ovulation occurred, there was an equal likelihood of ipsilateral or contralateral ovulation in the succeeding cycle. However, ovulation-inducing drugs increase the incidence of bilateral or multiple ovulation.

Clomiphene↗
PubMed1992

The duration of ovulation in pigs, studied by transrectal ultrasonography, is not related to early embryonic diversity.

The duration of ovulation in pigs was studied by transrectal ultrasonography. The number of preovulatory follicles was counted on both ovaries at 30-minute intervals from 36 hours after the onset of estrus (Group A: naturally ovulating sows that were group-housed and were inseminated and caged during scanning) or 40 hours after treatment with human chorionic gonadotropin (hCG) (Group B: tethered sows that had been induced to ovulate but were not inseminated). The duration of ovulation was (mean+/-SD) 1.8+/-0.6 hours (range 0.75 to 3.25) in Group A (n=13) and 4.6+/-1.7 hours (range 2.0 to 7.0) in Group B (n=8). The difference was significant (P<0.01). In Group A and B sows, respectively, the course of ovulation, expressed as the relation between the relative follicle count (percentage of the maximum follicle count; Y) and the time (percentage of the duration of ovulation; X) was: Y=104.3*e(-0.023*X) (R2=0.95) and Y=98.9*e(-0.018*X) (R2=0.92). The onset of ovulation occurred at approximately two-thirds of the duration of the estrus (Group A: 67+/-6%; Group B: 60+/-10%). Group A sows were artificially inseminated and were slaughtered at 98+/-8 hours (range 77 to 110) after ovulation. The difference between the maximum follicle count and the corpora lutea count was zero or only 1 in 81% (21/26) of the ovaries. Embryonic diversity (within-litter SD of the number of nuclei or of the number of cell cycles) was not related to the duration of ovulation, neither at the level of ovary nor of sow (P>0.05). In conclusion, transrectal ultrasonography was found to be an appropriate nonsurgical method of studying the duration of ovulation in pigs. The duration of ovulation varied both between sows and between groups of sows, and was not related to early embryonic diversity.

Journal Article↗
PubMed1994

Fertilization rates in superovulated and spontaneously ovulating mares.

Embryo recovery per ovulation has been shown to be lower in superovulated mares than in untreated controls. The objectives of this study were to 1) determine whether follicles stimulated with superovulatory treatment ovulate or luteinize without ovulation, 2) determine fertilization rates of oocytes in oviducts of superovulated and control mares, and 3) evaluate viability of early stage embryos from superovulated and control mares when cultured in equine oviductal cell-conditioned medium. Cyclic mares were randomly assigned to 1 of 2 groups (n=14 per group) on the day of ovulation (Day 0): Group 1 received 40 mg of equine pituitary extract (EPE; i.m.) daily beginning on Day 5 after ovulation; mares assigned to Group 2 served as untreated controls. All mares were given 10 mg PGF(2alpha) on Day 5 and Day 6, and 3,300 IU of human chorionic gonadotropin (hCG) were administered intravenously once mares developed 2 follicles >/=35 mm in diameter (Group 1) or 1 follicle >/=35 mm in diameter (Group 2). Mares in estrus were inseminated daily with 1 x 10(9) progressively motile spermatozoa once a >/=35 mm follicle was obtained. Two days after the last ovulation the ovaries and oviducts were removed. Ovaries were examined for ovulatory tracts to confirm ovulation, while the oviducts were trimmed and flushed with Dulbeccos PBS + 10% FCS to recover fertilized oocytes. All fertilized oocytes (embryos) recovered were cultured in vitro for 5 d using TCM-199 conditioned with equine oviductal cells. Ninety-two percent of the CL's from EPE mares resulted from ovulations compared with 94% for mares in the control group (P>0.05). The percentages of ovulations resulting in embryos were 57.1 and 62.5% for EPE-treated and control mares, respectively (P>0.05). Eighty-eight (Group 1) and 91% (Group 2) of the freshly ovulated oocytes recovered were fertilized (P>0.05). After 5 d of culture, 46.4 and 40.0% of the embryos from EPE-treated and control mares developed to the morula or early blastocyst stage (P>0.05). In summary, the CL's formed in superovulated mares were from ovulations not luteinizations. Although embryo recovery was less than expected, fertilization rates and embryo development were similar (P>0.05) between superovulated and control mares.

Journal Article↗
PubMed2004

Effect of ovule position within the pod on the probability of seed production in Bauhinia ungulata (Fabaceae).

BACKGROUND AND AIMS: It has been claimed that ovules linearly ordered within a fruit differ in their probabilities of reaching maturity. This was investigated by studying the effect the position of an ovule within the pod has on seed abortion and seed production in Bauhinia ungulata. METHODS: Fruits collected during the dry seasons of 1999, 2000 and 2001 were opened, and the number, position and status of each ovule within the fruit were recorded. A GLM model was used to assess the effects of population, tree identity and ovule position within the pod on ovule fertilization, seed abortion, seed damage and seed maturation in two populations of B. ungulata. KEY RESULTS: Nearly 30% of the ovules were not fertilized in 1999; this percentage dropped to 5% the following two years. Seed abortion (50%) and seed damage (15%) were the same every year during the study period. Only 15% of the initial ovules developed into mature seeds in 1999; this value increased to 35% in 2000 and 2001. However, seed survivorship was dependent on the position of the ovule within the pod; non-fertilized and early aborted ovules were found more often near the basal end of the ovary. The frequency of seed damage was not affected by position. Mature seeds were found mainly in the stylar half of fruits, where ovules are likely to be fertilized by fast pollen tubes. CONCLUSIONS: The pattern of seed production in B. ungulata is non-random but is dependent upon the position of the ovule within the pod. The results suggest that the seeds produced within a fruit might differ in their vigour.

Bauhinia↗
PubMed2006

Comparison of the effect of natural mating, LH, and GnRH on interval to ovulation and luteal function in llamas.

Gonadotropins and GnRH have been used to electively induce ovulation in llamas and alpacas, but critical evaluation of the natural interval to ovulation after mating has not been performed nor has a direct comparison of the effects of natural mating versus hormone treatments on this interval and subsequent luteal development. The objectives of this study were to compare the effects of hormonal treatments and natural mating on ovulation induction, interval to ovulation, and luteal development in llamas. The ovaries of llamas were examined by transrectal ultrasonography once daily. Llamas with a large follicle were assigned randomly to be: (1) mated with an intact male (mated; n=10); (2) given 5 mg of LH im (LH; n=11); or (3) 50 microg of GnRH im (GnRH; n=10). Ultrasound examinations were performed every 4h from treatment (day 0) to ovulation and thereafter once daily for 15 consecutive days to monitor CL growth and regression (n=5 per group). Plasma progesterone concentrations were measured at days 0, 3, 6, 9, and 12 after treatment to evaluate CL function. The size of the largest preovulatory follicle at the time of treatment did not differ among groups (11+/-0.6, 10.5+/-0.8, 11.8+/-0.9 mm, for mated, LH, and GnRH groups, respectively; P=0.6). No differences were detected among groups (mated, LH, and GnRH) in ovulation rate (80%, 91%, 80%, respectively; P=0.6), or interval from treatment to ovulation (30.0+/-0.5, 29.3+/-0.6, 29.3+/-0.7h, respectively; P=0.9). Similarly, no differences were detected among groups (mated, LH, and GnRH) in maximum CL diameter (14.2+/-0.3, 13.2+/-0.5, and 13.0+/-0.7 mm, respectively; P=0.5), the day of maximum CL diameter (7.6+/-0.2, 7.6+/-0.2, and 7.4+/-0.4 mm, respectively; P=0.6), or the day on which the CL began to regress (12.3+/-0.3 [non-pregnant, n=3], 11.8+/-0.6, 12.2+/-0.4, respectively; P=0.4). The diameter of the CL and plasma progesterone concentrations changed over days (P<0.0001) but the profiles did not differ among groups. In summary, ovulation rate, interval to ovulation, and luteal development were similar among llamas that were mated naturally or treated with LH or GnRH. We conclude that both hormonal preparations are equally reliable for inducing ovulation and suitable for synchronization for artificial insemination or embryo transfer program.

Animals↗
PubMed2004

Influence of repeated rectal ultrasound examinations on hormone profiles and behaviour around oestrus and ovulation in dairy cattle.

Frequent rectal ultrasound is often used to assess time of ovulation. This study investigated whether frequent rectal ultrasound examination, affects behavioural oestrus and peri-ovulatory hormone profiles (LH, oestradiol and progesterone). Additionally, the relation between peri-ovulatory hormone profiles, oestrous behaviour and time of ovulation was studied. Oestrus was synchronised in two consecutive cycles of Holstein Friesian cattle (parity from 1 to 6; n = 24 cycles). In 12 of these cycles, time of ovulation was assessed by three-hourly rectal ultrasound (assessment of ovulation time with ultrasound group: UG) the other half served as controls (n = 12; no assessment of ovulation time group: CG). There were no significant differences between the onset of oestrus (33.8 +/- 1.6 h), duration of oestrus (13.4 +/- 0.9 h) or intensity of oestrous behaviour (1047 +/- 180 points) between UG and CG treated animals. Furthermore, LH, oestradiol and progesterone profiles were similar between UG and CG. For UG, ovulation took place 30.2 +/- 1.9 h after onset of oestrus. This interval had the largest variation (21 h) of all parameters studied, ranging between 19 and 40 h after onset of oestrus. The smallest variation (6 h) was found in the timing of ovulation in relation to the LH-peak; ovulation took place 25.3 +/- 0.6 h (range: 21.5-27.5 h) after the peak in LH. This study demonstrated that repeated rectal ultrasound does not alter behavioural oestrus or peri-ovulatory hormone profiles and is therefore a useful tool for assessing time of ovulation. Further research, using ultrasound, can now be carried out to find predictors for time of ovulation.

Animals↗
PubMed2005

Incidence of spontaneous ovulation and development of the corpus luteum in non-mated dromedary camels (Camelus dromedarius).

The occurrence of spontaneous ovulation in dromedaries was examined in two separate studies including 20 non-lactating, barren and 12 lactating dromedaries, respectively. Lactating camels were milked twice a day with an automatic bucket milking machine. Ovarian activity was monitored by repeated ultrasonography. Blood samples for progesterone were collected daily or two to three times a week. To compare CL development after spontaneous and induced ovulations, ovulation was induced by a GnRH analogue in eight lactating dromedaries. Spontaneous ovulation was observed in one non-lactating camel (1 of 20 camels, 5%; 1 of 70 follicular waves, 1.4%), whereas, spontaneous ovulation was detected more frequently in lactating dromedaries (5 of 12 camels, 41.7%; 13 of 91 follicular waves, 14.3%). In one lactating camel, spontaneous ovulation occurred repeatedly for nine times. There was a significant effect of type of ovulation (spontaneous versus induced, P < 0.05) and day (P < 0.001) on serum progesterone concentration. Mean serum progesterone levels and total progesterone production (AUC) were higher after induced ovulation. Luteal diameter and serum progesterone concentration were positively correlated (r = 0.71, P < 0.001), but there was a significant difference between morphological and functional development of the CL. In dromedaries, morphological development starts earlier, morphological regression starts later and last longer than functional development and regression of the CL. Compared to induced ovulation, functional development of the CL after spontaneous ovulation might be altered but the morphological development is not affected.

Animals↗
PubMed1999

Effect of milk production on the incidence of double ovulation in dairy cows.

To determine the effect of parity and milk production on the incidence of double ovulation, the synchronization of ovulation, using GnRH and prostaglandin F2 alpha followed by timed AI (Ovsynch), was initiated at a random stage of the estrous cycle in lactating Holstein cows (n = 237). Ovulatory response at 48 h after the second GnRH injection and conception rate at 28 d post AI were determined by transrectal ultrasonography. Ovulation was synchronized in 84% of cows receiving the Ovsynch protocol. Of the synchronized cows, 14.1% exhibited a double ovulation and 47.6% conceived. Conception rate tended to be greater (P = 0.08) for cows exhibiting double (64.0%) rather than single ovulation (45.2%). To determine the effect of milk production on the incidence of double ovulation, cows were classified into low (< or = 40 kg/d) or high (> 40 kg/d) milk production groups based on the average milk production of 40.5 +/- 0.8 kg/d collected 2 d before AI. Although the incidence of double ovulation tended to increase linearly (P = 0.09) with increasing parity, the incidence of double ovulation was nearly 3-fold greater (P < 0.05) for cows in the high (20.2%) than the low (6.9%) milk production group. Furthermore, the increase in the incidence of double ovulation with parity apparently occurred because, within a parity group, the proportion of cows with high milk production was greater for the older cows. Twinning rate of cows that calved (n = 58) was 5.2%. In a secondary objective, cows were retrospectively classified as cystic or normal based on ultrasonographic ovarian morphology at the time of the second GnRH injection. Incidence of ovarian cysts was 11%, and the synchronization and conception rate of cows classified as cystic was 73.1 and 36.8%, respectively, which did not differ from that of normal cows. We conclude that milk production is the primary factor affecting the incidence of double ovulation in lactating dairy cows and may explain the effect of parity on twinning rate. In addition, Ovsynch appears to be an effective method for establishing pregnancy in lactating dairy cows with ovarian cysts.

Animals↗
PubMed1998

Presence of males affects the incidence of ovulation after pouch young removal in brushtail possums (Trichosurus vulpecula).

The traditional method for inducing and synchronising oestrus in the brushtail possum (Trichosurus vulpecula) is by removal of their suckling pouch young (RPY). However, our studies have recently shown that, in addition to wide variation between animals in the time of ovulation after RPY, a proportion of animals failed to ovulate. Evidence from several mammalian species indicates that the presence of males can stimulate ovarian activity and synchronise oestrus in females. The aim of this study was to determine the effect of the male on the oestrous cycle of the female brushtail possum after RPY. A total of 67 adult female brushtail possums were treated as three replicates. In order to observe the day of preovulatory follicle emergence and ovulation, animals underwent laparoscopic examination at 1-4 day intervals over a period from 0-21 days after RPY. The first replicate (N = 18, May/June 1995) involved only animals kept in isolation from males, whereas the two remaining replicates compared ovarian responses between animals kept with ( N = 10, July 1995; N = 14, June 1996) or in isolation from ( N = 10, July 1995; N = 15, June 1996) males. The incidence of ovulation after RPY was significantly higher in females that were housed with males than in those kept in isolation from males (100%, 92.8% vs. 50.0%, 66.7%, 14.3%; P < 0.001). Every animal that ovulated, had previously had a preovulatory follicle present at the site where the corpus luteum formed. Conversely, none of the animals that failed to ovulate, developed a preovulatory follicle during the period of the study. The range of mean day of preovulatory follicle emergence (6.00-6.86 days), of ovulation (11.80-12.20 days) and the synchrony of ovulation between animals (range 8-17 days) after RPY, were not significantly affected by the presence of males. This study demonstrates for the first time, that the presence of males significantly increases the incidence of ovulation after RPY in the brushtail possum. However neither the timing of reproductive events nor the synchrony of ovulation were affected by presence of the male.

Animals↗
PubMed1995

Ovulation as determined by transrectal ultrasonography in multiparous sows: relationships with oestrous symptoms and hormonal profiles.

Twenty-four cross-bred multiparous sows in their second and fourth parities were studied during two consecutive oestruses after weaning. Careful oestrous control was done on the animals and ovulation was monitored by transrectal ultrasonography. Blood for analysis of LH and E2 contents was collected through an indwelling catheter. The sows were mated/inseminated once approximately 18 h before expected ovulation in their second oestrus. The interval between weaning and ovulation varied from 86 h-204 h (153 +/- 26). Onset of standing oestrus to ovulation was found to be longer in sows with long oestruses and ovulation occurred within a mean of 68% of the oestrous period. Duration of the first pro-oestrus was significantly shorter than the second pro-oestrus (40 h and 71 h, respectively). There was no significant difference within sows for the intervals from onset of oestrus to ovulation during the first and second oestrus after weaning (37 h and 39 h, respectively). The diameter of the largest follicles at onset of oestrus and at ovulation had very small variation between animals. The mean intervals from E2 peak to onset of oestrus and to ovulation were 1 h (range -10-(+)22 h) and 44 h (range 34-54 h) respectively, and from LH peak to onset of oestrus and to ovulation 12 h range -10-(+)32 h) and 35 h (range 27-48 h), respectively. The present study indicates that repeated ultrasonographic examination of ovaries during one oestrus can be used to predict the time of ovulation during the subsequent oestrus.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2000

Plasma LH and progesterone levels before and after ovulation and observation of ovarian follicles by ultrasonographic diagnosis system in dogs.

Recently, canine frozen semen has been attracting attention for breeding purposes, and methods of judging ovulation and optimum timing for insemination have become important. As methods of predicting the canine ovulation, vaginal smear, plasma sex hormone levels and ultrasonographic diagnosis system (US) have been investigated in combination, but a standard technique has not yet been established. Therefore, we investigated a method of predicting canine ovulation in dogs by US, and by measuring plasma LH and progesterone (P) levels three times a day. Ovulation could be observed by detecting irregularly shaped ovarian follicles by US in six of 11 dogs (54.5%). In these dogs, the time between the LH peak and ovulation was 24-48 hr, 38.0 hr on average. The P level on the ovulation day was 1.88-2.81 ng/ml, 2.34 ng/ml on average. A value of 1.88 ng/ml was detected in one dog, but the other five dogs showed P levels of 2 ng/ml or higher. The P level on the day before ovulation was 0.8-1.56 ng/ml, 1.12 ng/ml on average. Assuming that ovulation occurred two days after the LH peak in the 11 experimental dogs, the P level was 2.12-4.06 ng/ml, 2.78 ng/ml on average. The period of a high LH level, not less than 10 ng/ml, continued for 12 hr around the LH peak. Based on these findings, to predict ovulation using US and LH level, it would be necessary for the tests to be performed several times a day. In contrast, it was shown that the day on which a plasma P level of 2 ng/ml or higher was detected by the test performed once a day corresponded to the ovulation day.

Animals↗
PubMed2004

Incidence of silent ovulation in dairy cows during post partum period.

The present study was undertaken to show the incidence of silent ovulation in high producing dairy cows, by monitoring ovarian cyclicity based on practical milk progesterone assay which was established in this study. The direct milk progesterone enzyme linked immunosorbent assay (ELISA) was developed using anti-progesterone-3(E)-carboxymethyloxime-BSA antibody for the antibody and horse radish peroxidase labeled progesterone for tracer. High sensitivity (26 pg/mL, 0.65 pg/well), high recovery rates (83-97%), high reproducibility (CV of intra-assay 4.8-11.5%; CV of inter-assay 14.3-19.1%) and high correlation between milk progesterone concentrations measured by the direct ELISA and the values obtained by the ELISA after extraction proved the reliability of the assay. In second experiment the incidence of silent ovulation was investigated based on the milk progesterone concentrations in 32 dairy cows within 70 days post partum. The incidences of silent ovulation at the first, second, third and fourth ovulation post partum were 83, 46, 13 and 0%, respectively. Most commonly observed patterns of sequential occurrence of silent ovulation in cows ovulating 2, 3 or 4 times within 70 days post partum were silent-estrus (50%), silent-silent-estrus (60%) and silent-silent-estrus-estrus (67%), respectively. These results suggest that the present ELISA is a reliable and practically applicable method for determination of progesterone in milk and that high producing dairy cows show a high incidence of silent ovulation at the first post partum ovulation as well as the second ovulation, which then decreased with the increased frequency of ovulation.

Animals↗
PubMed1983

The role of plasminogen activator in ovulation.

The role of plasminogen activator in ovulation was investigated using the inhibitor, trans-aminomethylcyclohexane carboxylic acid (t-AMCHA). In the regular cycle rat, the plasminogen activator activity of the follicles increased from the diestrus to the estrus phase. In the latter phase, a proteolytic enzyme which was not inhibited by t-AMCHA appeared. After ovulation, the plasminogen activator activity decreased. When ovulation was induced in immature rats by pregnant mare serum gonadotrophin and human chorionic gonadotrophin, remarkable fibrinolytic activity appeared in the ovaries immediately before ovulation. When t-AMCHA was given in the ovulation-induced rats, the fibrinolytic activity of the ovaries was suppressed, the number of ovulated ova decreased and the timing of ovulation was delayed. When t-AMCHA solution was given to rats in the proestrus phase, ovulation was almost completely suppressed, but aprotinin solution exerted no effect on ovulation. These results suggest that plasminogen activator is a key enzyme in ovulation, and that the chain reaction from plasminogen activator to proteolytic enzyme (including collagenase) is of greater importance than that of plasminogen activator to plasmin.

Animals↗
PubMed1982

The role of androgens in follicular development in the ovary. I. A quantitative analysis of oocyte ovulation.

In an attempt to understand more fully processes that control the selection or recruitment of follicles for ovulation, the superovulation paradigm in combination with the androgen, 5 alpha-dihydrotestosterone, or the antiandrogens, cyproterone or cyproterone acetate, was used in the immature mouse to alter the developmental potential of follicles destined to ovulate or to become atretic. Quantitative analysis of the numbers of eggs ovulated after one or more rounds of stimulation by pregnant mare's serum gonadotrophin followed by human chorionic gonadotrophin (PMSG-hCG), revealed a dose-dependent ovulation response to exogenous androgen and antiandrogen. Low dosages of androgen improved the ovulation response significantly. Large dosages of cyproterone and cyproterone acetate (100 mg/kg body weight) generally decreased the ovulation number in gonadotrophin-injected mice, suggesting a role for androgen in preovulatory events that occur within the ripened follicle after the ovulatory stimulus (hCG) has been received. Low dosages of cyproterone, particularly 25 mg/kg, significantly enhanced the ovulatory response, a phenomenon not observed for cyproterone acetate at this dosage. Radioimmunoassays of serum LH suggested that the differential response of the ovary to the two antiandrogens was probably related to endogenous LH release. Experiments in which the time of administration of hCG +/- cyproterone was varied after PMSG priming suggested that cyproterone at a dosage of 25 mg/kg had a "rescuing" effect on follicles destined to become atretic for up to 96 hr after PMSG priming. Cyproterone at a dosage of 100 mg/kg had no such effect, and actually decreased the magnitude of the ovulatory response at all time points tested, suggesting that follicular atresia was accelerated by this treatment. Experiments in which the time of administration of cyproterone (100 mg/kg) was varied after hCG suggested that whatever the important androgen-mediated events preceding ovulation, these events occur within 2 to 3 hr after the hCG signal. By quantitating the numbers of eggs over several superovulation cycles, it could be shown that hormonal treatment in one induced cycle could affect significantly the ovulation response in subsequent cycles, suggesting that androgens influence the development of classes of follicles other than preovulatory follicles. These studies suggest that the process through which follicles are selected for ovulation is extremely sensitive to the androgenic environment and that the developmental pathways leading to ovulation or preovulatory follicular atresia are closely linked.

Animals↗
PubMed1980

Reversal of indomethacin blockade of ovulation in gilts by prostaglandins.

Prepubertal gilts given 750 IU pregnant mares' serum gonadotropin (PMSG) followed 72 h later by 500 IU human chorionic gonadotropin (hCG) to induce follicular growth and ovulation fail to ovulate when 10 mg/kg indomethacin (INDO) is injected 24 h after hCG administration. This study examines the effects of administration of exogenous prostaglandins F2 alpha and E2 (PGF2 alpha and PGE2) alone or in combination, and at various times prior to the expected time of ovulation, on the INDO blockade of ovulation in PMSG/hCG-treated gilts. Occurrence of ovulation was determined by visual observation at laparotomy 48 h after hCG. When 5 mg or 10 mg PGF2 alpha was injected at each of 38, 40 and 42 h after hCG injection, 63% and 79%, respectively, of preovulatory follicles ovulated. In contrast, injection of 5 mg PGE2 or 5 mg PGE2 plus 5 mg PGF2 alpha induced ovulation in 0% and 24% of preovulatory follicles, respectively. In control groups, 100% of follicles in PMSG/hCG-treated gilts ovulated whereas none did so in PMSG/hCG/INDO-treated animals. These results indicate that administration of PGF2 alpha can induce ovulation in the PMSG/hCG/INDO-treated prepubertal gilt and suggest that PGE2 is ineffective and may be antagonistic to PGF2 alpha in overcoming the ovulation blocking effect of INDO.

Animals↗
PubMed2005

Relationship between progesterone concentrations in milk and blood and time of ovulation in dairy cattle.

The objective of this study was to investigate whether monitoring progesterone concentrations in milk and blood plasma can be used to predict time of ovulation in dairy cattle. Whole milk was sampled twice daily and blood samples were collected once a day before the morning milking. Ovulation was assessed by trans-rectal ultrasonography at 4h intervals beginning from the end of estrus. For a parameter to be useful as predictor for time of ovulation, it should be precise (i.e. variation between animals should not exceed 12h). In milk, progesterone concentration dropped <15 ng/ml at 97.7+/-17.8h (range: 54-126 h) before ovulation, to <5 ng/ml at 79.7+/-11.2h (range: 54-98) before ovulation to decline further to <2n g/ml at 70.7+/-16.8h (range: 38-90 h) before ovulation (n=20). In plasma, progesterone concentration dropped to <4ng/ml 90.5+/-19.6h (range: 66-138 h) before ovulation and to <2 ng/ml at 75.0+/-12.2 h (range: 50-98) before ovulation. These intervals were not influenced by parity, milk production or days in milk. In conclusion, monitoring of progesterone alone is not sufficient to predict ovulation because of the large variation in timing of decrease of progesterone concentrations relative to ovulation between animals. At best the range is about 2 days.

Animals↗
PubMed1982

Relation between ultrasonographic evidence of ovulation and hormonal parameters: luteinizing hormone surge and initial progesterone rise.

Relations between ultrasonographic signs of ovulation, the luteinizing hormone (LH) surge, and progesterone rise were documented in 28 and 24 spontaneous ovulations, respectively. Two definitions for LH surge were applied to a series of daily LH determinations. The first LH rise was recorded 48 to 11 hours before ultrasonographic signs of ovulation. The best estimate of the LH peak preceded ovulation by 24 to 11 hours, two extremes excluded. The mean progesterone values during the observed ovulation period were in agreement with data in the literature concerning ovulation period were in agreement with data in the literature concerning ovulation timing by corpus luteum histologic features. A considerable intercycle variation is reported in progesterone level and in the slope of the progesterone increase around ovulation. It is concluded that ultrasonographic signs of ovulation might be closely related to anatomic ovulation.

Female↗
PubMed1999

Efficacy of methods for determining ovulation in a natural family planning program.

OBJECTIVE: To evaluate the efficacy in ovulation detection of methods used in natural family planning in comparison with pelvic ultrasonography. DESIGN: Prospective analysis of ovulation detection by natural family planning methods and ultrasonography. SETTING: Natural family planning clinic, Department of Obstetrics and Gynecology, University of Naples "Federico II". PATIENT(S): Forty healthy women who were highly motivated to use natural family planning. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Transvaginal ultrasonographic findings, urinary LH levels, salivary beta-glucuronidase activity, salivary ferning levels and characteristics of cervical mucus, and BBT. RESULT(S): Urinary LH level determination yielded a 100% correlation with the simultaneous ultrasonographic diagnosis of ovulation. Mucus sensations and characteristics yielded a 48.3% correlation when simultaneously evaluated with ovulation. Beta-glucuronidase levels yielded a 27.7% correlation. The salivary ferning test had a 36.8% ovulation-detection rate the day of ovulation, but 58.7% of results were uninterpretable. Body temperature measurements yielded a 30.4% correlation with the simultaneous ultrasonographic diagnosis of ovulation. CONCLUSION(S): Measuring urinary LH levels is an excellent method for determining ovulation. Although variations in mucus characteristics and basal body temperature correlate somewhat with ovulation, the length of the fertile period is overestimated with these methods. The salivary ferning test and measurement of beta-glucuronidase levels are not good methods for home ovulation testing.

Adult↗