Time Of Ovulation Research Articles

P-607 Interindividual variation of progesterone elevation post LH rise: Implications for natural cycle frozen embryo transfers in the individualized medicine era.

Abstract Study question To what extent does the period between LH-rise and P4-rise vary in ovulatory natural menstrual cycles? Summary answer Three distinct ovulatory patterns were noted defined as the period between LH-rise and P4-rise and varied by up to two days. What is known already The key to success of FET in a NC is the accurate diagnosis of ovulation to determine the optimal timing of embryo transfer. The most common method used to determine time of ovulation in NC is the detection of luteinizing hormone (LH) surge. It is well recognized that the endocrine profile of menstrual cycles varies not only amongst women but also from cycle to cycle for any given female. Most hormone trajectories in individual women differ considerably from the mean hormonal curves and LH surges culminating in ovulation appear to be highly variable in timing, amplitude and duration. Study design, size, duration Retrospective, observational study including 102 women who underwent endocrine monitoring during a frozen embryo transfer in a natural cycle between 1st January 2017 and 31st August 2021 in a tertiary IVF centre. Participants/materials, setting, methods Ultrasound scans were performed to monitor follicular growth. Serial measurements of serum LH, FSH, estradiol and P4 were commenced once a dominant follicle measuring ≥ 14mm was identified and on three consecutive days until (including) the day of ovulation. The LH surge was considered to have begun when the concentration rose by 180% above the most recent serum value. Progesterone concentrations of 1.0ng/ml and above were regarded as confirmation of ovulation to schedule FET. Main results and the role of chance Patients’ characteristics presented as median and (range): age 35 years (23-43), BMI 25.24kg/m2 (17.32-38.21), AMH 2.07 ng/ml (0.06-8.12). Twenty-one (20.6%) women had the LH-rise 2 days prior to P4 -rise, 71 (69.6%) had on the day immediately preceding and 10 (9.8%) on the same day of P4-rise. If FET was scheduled based on LH-rise, 30.4% of the patients would have their FET scheduled on a different day than FET scheduled according to P4-rise. The period between LH-rise and P4-rise would be approximately one day longer in 20.6% of the participants and one day shorter in 9.8% than the anticipated 24 hour period. There was a significant difference in body mass index between those women who had LH-rise 2 days prior to P4-rise (BMI 26.91 kg/m2 (range 23.74-30.75) and the women who had LH-rise on the same day (BMI 22.39 kg/m2 (range 20.91-24.96) (p = 0.03). The AMH levels were also found to be significantly lower in those women who had LH rise 2 days prior to P4-rise ( AMH 1.59 ng/ml (range: 0.82-2.09) as compared to those who had LH-rise on the same day (AMH 2.67ng/ml (range: 1.83—6.63) (p = 0.04). LH may not serve as the best benchmark to schedule FET. Limitations, reasons for caution Frozen embryo transfers were scheduled according to serum progesterone levels therefore our study does not provide a direct answer to the question whether FET scheduled according to serum progesterone levels provides higher live birth rates than FET scheduled based on urinary or serum LH levels in a natural cycle. Wider implications of the findings Variation in the period between LH rise and progesterone rise in ovulatory cycles has implications for the choice of marker for the start of secretory transformation in frozen embryo transfer cycles. The study participants are representative of the relevant population of women undergoing frozen embryo transfer in a natural cycle. Trial registration number Not Applicable

GnRH34 with or without estradiol cypionate in timed AI in Bos indicus beef cows

Two experiments were performed to evaluate the effects of GnRH treatment on the fertility of suckled Nelore beef cows treated with an estradiol/progesterone (E2/P4)-based protocol for timed artificial insemination (TAI). Experiment 1 focused on determining the effects of estradiol cypionate (EC) on ovulation in TAI cows treated with GnRH 34 h after removal of the intravaginal P4 device (IPD). Suckled cows (n = 26) were treated with 2 mg estradiol benzoate (EB) and IPD containing 1 g P4. After 8 days, IPDs were removed, and all cows were treated with 150 μg of d-cloprostenol (prostaglandin F2 alpha analog) and 300 IU of equine chorionic gonadotropin (eCG), then separated into two treatment groups consisting of cows who received 1) saline 0.9% i.m. (GnRH34 group) or 2) 0.6 mg i.m. of EC (EC-GnRH34 group). On day 9 (05:00 p.m.), all cows were given GnRH (10.5 μg of buserelin acetate) i.m. No differences were observed between the groups (P > 0.05) in the time of ovulation after IPD removal or in the proportion of cows ovulating. Experiment 2 focused on determining the effects of GnRH34 along with or in the absence of EC on day 8 on pregnancy per AI (P/AI) in postpartum beef cows. Cows (n = 981) were treated similarly to those in Experiment 1, but an additional group, the EC-GnRH48 group, was included, in which cows received EC on day 8 whereas those that did not show estrus received GnRH at TAI. Thus, in this experiment, groups consisted of GnRH34 (n = 322), EC-GnRH34 (n = 335), and EC-GnRH48 (n = 324). A higher rate of estrus expression was observed in cows treated with EC following IPD removal (EC-GnRH34: 69%, EC-GnRH48: 64.8%) than in cows in the GnRH34 group (45.6%). No difference in P/AI was observed between the treatment groups (P = 0.45), but P/AI in cows in the EC-GnRH34 group (64.2%) tended to be greater (P = 0.1) than in cows in the GnRH34 group (58%). In summary, although ovulation synchrony did not differ among the groups, P/AI in cows treated with EC and GnRH 34 h after IPD removal tended to be greater than in cows treated solely with GnRH; this was most likely due to a shorter proestrus/estrus period, considering the lower proportion of cows that displayed estrus in the GnRH34 group. Finally, given that P/AI did not differ between the EC-GnRH34 and EC-GnRH48 groups, our results suggest that, for cows not displaying estrus, administration of EC at the time of IPD removal followed by treatment with GnRH 48 h afterward represents the most cost-efficient TAI strategy for South American Zebu-based beef operations.

Application of Exogenous GnRH in Food Animal Production.

Over several decades, exogenous GnRH and agonists have been employed for controlling reproductive cascades in animals, and treating some reproductive morbidities. The administration of GnRH is used in animals to counter ovarian dysfunction, induce ovulation, and to increase conception and pregnancy rates. GnRH and its agonists are used in the treatment of cystic ovarian degeneration and repeat breeder syndrome. The development of protocols for GnRH administration by intramuscular injection, intramuscular or subcutaneous implants, and intravaginal deposition has empowered their clinical use worldwide. Currently, exogenous GnRH products are a central part of several pre- and post-breeding programs for the enhancement of fertility, including the control of estrous cycles and timing of ovulation, development of fixed-time artificial insemination protocols, improved embryo survival, and the treatment of reproductive morbidity. The aim of the present review is to summarize the application of exogenous GnRH agonists in food animal production.

Cervix-deep rectal temperature differential on the day of ovulation is correlated with embryo recovery results

In many species, the reproductive tract experiences a temperature decrease before ovulation to aid gamete maturation. For example, pre-ovulatory follicles are ≤1.0°C cooler than ovarian stroma in cattle, and a lower temperature differential (TD) between cervix-rectum at the time of insemination has been correlated with pregnancy in cows. The present study aimed to compare TDs (cervix-deep rectal) in positive versus negative embryo recovery cycles. Deep rectal and cervical temperatures were measured using a precision thermometer with a 30cm probe (Electronic Temperature Instruments Ltd, UK; resolution 0.01°C, accuracy ±0.05°C) in 19 mares over 32 estrous cycles. Mares were inseminated with a fertile stallion and excluded if they required any treatment other than oxytocin administration. Embryo flushing was undertaken on Day 7/8. Deep rectal and cervical temperatures were taken on 5 occasions: the day of deslorelin administration and insemination, the day before ovulation, the day of ovulation (Day 0), one day post ovulation and before embryo recovery on Day 7 or 8. Statistical analysis was undertaken using the Mann-Whitney Rank Sum test. The median TD (cervix-deep rectal), and cervical and deep rectal temperatures were compared between cycles with a positive versus negative embryo recovery. From the 32 cycles, 21 (65.6%)cycles produced an embryo. On the day of ovulation positive cycles showed a lower median TD than negatives ones (0.19 vs. 0.40 °C; p=0.001). For the 11 negatives cycles a lower median TD was seen in the two days prior to ovulation versus the day of ovulation and the day of embryo recovery (p≤0.023 in all cases). For positive cycles lower median TDs were seen at all time points from induction till one day after ovulation versus the day of embryo recovery (p<0.007 in all cases). For rectal or cervical temperatures per se no significant differences were seen between positive and negative cycles at any time point. However, in negative cycles median cervical temperature was lower the day before ovulation versus the day of embryo recovery (p=0.014). In positive, but not negative, cycles the median rectal temperatures on the day of induction, ovulation and the day after ovulation were higher than on the day of embryo recovery (p<0.035 for all days). In conclusion, as in cattle, a thermoregulatory process occurs at the time of ovulation in the mare in which a lower TD between cervix and rectum is related to a greater likelihood of pregnancy. Further characterization of TDs within the reproductive tract of the mare would increase our understanding of the conditions required for oocyte maturation.

Embryo recovery on consecutive days from Day 6.5 to obtain small embryos for vitrification: Is it effective?

To successfully vitrify equine embryos without aspiration or puncture of the blastocoele cavity, current methodology requires embryos ≤300µm. Such embryos are obtained by flushing mares shortly after the presumed time of entry of the embryo into the uterus (6–6.5 days post ovulation). Ovulation, and hence the timing of the flush, is usually calculated from expected ovulation times following administration of an induction agent. However, recovery rates tend to be lower at 6.5 days. A precise time for ovulation helps, but its determination is management intensive, and entry into the uterus varies by a reported 12h. The aim of this study was to determine if flushing donor mares on successive days after they failed to give an embryo on Day 6.5-7 increased recovery rates of embryos ≤300µm. During successive breeding seasons 442 inseminated cycles from donor mares, aged 3-21 years, were flushed for embryos on Day 6.5-7 with the aim of obtaining embryos ≤300µm for vitrification. Mares were flushed with Ringer's Lactate in a closed system and oxytocin given before the third flush. Filter contents were placed in a Petri dish prior to rinsing the filter with 10% PVA in Ringer's Lactate. If no embryo was found flunixin meglumine was administered and the mare re-flushed 24h later. From 442 first flushes 151 (34.2%) were positiveand 168 embryos were recovered with a median diameter of 170 µm (range; 140-320µm). The 292 negative mares, and 3 double-ovulating mares that yielded only one embryo at the first flush, were re-flushed the following day with 49 (16.6%) positive flushes yielding 51 embryos (180µm; 150-400µm). A subset of the negative mares from the second recovery attempt (n=35) were flushed the following day and 7 (20.6%) gave embryos with a median diameter of 170µm (range; 150-200 µm). Combining all flushing days, 226 embryos were recovered of which only 4 (1.8%) were ≥300µm. Although approaching significance, no difference existed in the size of embryos recovered at the first, second or third flush (P=0.051). Mare age did not appear to be a factor on the likelihood of embryo recovery on the first, second or third attempt (12 vs. 14 vs. 12 y.o., respectively; P=0.130). Therefore, when flushing donor mares to recover embryos ≤300µm, re-flushing negative mares on consecutive days results in recovery of embryos suitable for vitrification without the need for blastocoele collapse. From a physiological aspect and allowing for the lack of a precise time for ovulation in the study, there appears to be a wider margin than Day 6–6.5 for entry of the embryo into the uterus.

The GnRH analogue Decapeptyl was able to induce ovulation in cyclic jennies

The aim of this study was to assess the ability of the GnRH analogue decapeptyl to induce ovulation of jennies in oestrus. Most of the northern hemisphere donkey breeds are faced with the risk of extinction (Camillo et al. J Equine Vet Sci 2018;65:44-49), thus donkey reproduction is considered an emerging branch of theriogenology and the management of induction of ovulation is a crucial point to set up preservation protocols (Carluccio et al. Theriogenology 2007;68:914-919; Camillo et al. Anim Reprod Sci 2014;151:56-60). In this study six Amiata jennies aged between 3 and 10 years, cyclic, in good general health and with a body condition score of ¾ were employed (Vall et al. in: Pearson, et al. Ed., 2003:93–102). For four consecutive cycles, jennies’ ovarian activity was routinely monitored; ultrasound examination was performed daily from the evidence of a follicle diameter ≥27 mm until ovulation. Upon reaching a follicular diameter ≥32±2 mm (hour 0), estrous jennies were treated alternatively with 100 mg Decapeptyl, sc, (DEC) or the equivalent volume of saline, sc, (CTRL) and examined ultrasonographically at hours 14, 24, 38, 42, 48, 62 and every 24 hours until ovulation. The experimental design was a 2 × 2 (with two replicates) Latin square. Induction of ovulation was considered successful if ovulation occurred between hours24 and 48 from treatment. An independent sample Student T Test and a Fisher Exact Test were performed to compare mean ovulation hour and ovulatory rates between DEC and CTRL groups, respectively. A forward stepwise multivariable logistic regression model based on the Wald statistics criterion of a P value smaller than 0.05 was used to establish significant predictors (group, jenny, and cycle number) for ovulation after treatment. Eleven/12 and 12/12 cycles resulted in ovulation for DEC and CTRL groups, respectively. Mean±SD ovulation time after treatment was 47.1±21.0 and 66.8±25.9 hours for DEC and CTRL respectively (P=0.059). Ovulation rates between 24h and 48h were 10/12 (83.3%) and 2/12 (16.7%) for DEC and CTRL respectively (P=0.003). Decapeptyl-treated jennies had a 25 times higher probability to ovulate between hours 24 and 48 than controls (P=0.003), while there were no jenny and cycle effects on the ovulatory rate. The results of this study show how Decapeptyl successfully induced ovulation in jennies, similarly to other GnRH analogs previously evaluated (Canisso et al. Vet Clin North Am Equine Pract 2019;35:607-642). Acknowledgments: The authors are grateful to Ente Terre Regionali Toscane for funding and for providing the jennies.

HCG versus histrelin acetate: ovulation inducing agents in mares (Equus caballus) in a commercial breeding program in Uruguay

Hormonal control of ovulation timing is an effective tool to optimize reproductive management and reduce costs in equine breeding programs. Few studies have evaluated the efficacy of GnRH analog histrelin as an ovulation inducer agent. This study aimed to compare the efficacy of human chorionic gonadotrophin (hCG) and histrelin as ovulation inducers in young, adult, and old mares during spring and summer. Reproductive records of 321 estrous cycles of 125 mares, mean age 9.8±0.37 years, range 1.5–24 years, between 360-600 kg body weight, and body condition ≥3 (1/5), were evaluated during spring (151 cycles) and summer (170 cycles). Mares were kept in the field and fed alfalfa hay, balanced concentrate feed and ad-libitum water. The ovaries, uterus, and cervix underwent transrectal examination and ultrasonography daily. When only one dominant follicle of 35 mm and endometrial edema compatible with estrus were reached, ovulation was induced. Each cycle was monitored every two to six hours until ovulation, 24h after induction. Cycles were randomly allotted in two groups; G1 (n=106 cycles): 1500 IU hCG (IV); G2 (n=215 cycles): 250 μg histrelin acetate (IM). A total of 119 cycles were from young (<8 years), 93 from adults (8-15 years), and 109 from old mares (>15 years). Cycles of mares ovulating within 24-48hafter treatment were considered to have responded to the inducer, and those ovulating before 24h and after 48h were excluded from the experiment. Inducer agents, season (spring or summer), and mare age were independent factors, and ovulation between 24-48h was considered the dependent factor. Data were analyzed through Fisher's exact test. The significance level was defined as P<0.05. From the 321 induced cycles, 254 (79.1%) ovulated within 24-48h, 20 (6.2%) before 24h, and 47 (14.6%) after 48h. There were no differences (P=0.2414) in the average response time between G1 (37.2h±3,5) and G2 (39.3h±4,5). The ovulatory response between G1 and G2 did not differ in spring (84.1% versus 90.7%, P=0.2627) and summer (79.2% versus 85.4%, P=0.3534). Independent of the inducer, the season did not influence the ovulation response in the different mare ages (spring P=0.1489; summer P=0.2992). No differences (P=0.896) were found between drugs in young and adult mares. However, old mares had a higher percentage of ovulatory response in spring and summer to histrelin (n=76) than to hCG (n=24) (89.5% versus 45.8%, P<0.0001). In conclusion, histrelin is more effective and accurate in inducing ovulation in old mares (>15 years) than hCG throughout the breeding season.

Kuluçkahane Kökenli F5 ve F6 Nesil Karadeniz Somonu Anaçlarının (Salmo labrax PALLAS, 1811) Üreme Performansları

In this study, reproductive performances of F5 and F6 generation hatchery-originated female Black Sea salmon (Salmo labrax) were evaluated to determine the effects of the ongoing selective breeding program. The study was conducted in freshwater pools and marine cage systems between 2018 and 2021. For the study, 53 specimens from F5 generation females with an average length of 52.71±7.08 cm and weight of 1561.29±639.76 gr, and also 56 broodstıcks specimens from F6 generation females with an average length of 51.92±5.35 cm and weight of 1506.12±417.28 gr were used. Gonad maturity controls and spawning studies were carried out in the 2018-2019, 2019-2020 and 2020-2021 breeding periods along the entire season, lasting from November to January. The number of ovulating females, their fecundity, egg diameters and fertilisation rates of eggs were recorded. In all seasons, 36.17% of F5 females ovulated in November, and the remaining females (63.83%) ovulated in December. Ovulation time in F6 females also showed a similar pattern of 1/3 of females (37.40%) ovulating in November and the remaining majority (62.60%) ovulating in December. According to the results, total egg yields as 4439.31±1675.69 and 4112.08±1041.16 egg/broodstock, relative egg yields as 2313.44±278.48 and 2345.76±516.30 egg/kg, egg diameters as 5.08±0.19 and 5.21±0.17 mm, and fertilisation rates as 96.78±3.24% and 96.63±3.73% were determined for F5 and F6 generations, respectively. In both generations, as the size of the broodstock increases, the total egg production increases (F5: r=0.9169, F6: r=0.74254), while the relative egg production (F5: r=-0.2526, F6: r=-0.3486) decreases. When the total egg yields and fertilisation rates were compared, the difference between the F5 and F6 groups was insignificant (p≤0.05). The condition factors of the two generations were found to be statistically similar (p≤0.05).

The parity affects the relationship between the insemination-ovulation interval and the conception rate in lactating dairy cows.

The aim of the present study was to investigate the relationship between parity and the optimal insemination-ovulation interval (IOI) in lactating dairy cows, as well as the relationship between the optimal timing of artificial insemination (AI) based on the onset of estrus and parity. A total of 183 postpartum lactating Holstein cows participated in the study and underwent 522 AI procedures using unsorted frozen semen between 2011 and 2018. Transrectal ultrasound was used to detect ovulation times in 326 AI procedures, and a pedometer was used to detect estrus onset times in 470 AI procedures. An analysis was also performed on data from 265 AI procedures in which all the times of estrus onset, estrus end, and ovulation were detected. The results showed that ovulation occurring 6-12 hr after AI was associated with the numerical highest conception rate in multiparous cows. Moreover, the conception rate was higher when ovulation occurred between 6 and 12 hr after AI than when it occurred between 0 and 6 hr or 18 and 24 hr after AI. In contrast, the effect of IOI on the conception rate in primiparous cows was insignificant. There was no effect of AI timing based on the estrus onset on the conception rate in either primiparous or multiparous cows. Furthermore, the interval from estrus onset to ovulation was similar in primiparous and multiparous cows. The difference in optimal IOI between primiparous and multiparous cows may be due to the larger uterus size in multiparous cows. These findings suggest that the optimal timing for AI in multiparous cows is more restricted than in primiparous cows. Therefore, it is essential to carefully determine the timing of AI when it is performed in multiparous cows.

Artificial intelligence: Friend or foe?

Artificial intelligence: Friend or foe?

Relationship between Clinical Uterine Findings, Therapy, and Fertility in the Mare.

Persistent breeding-induced endometritis (PBIE) is a major cause of subfertility in horses and the susceptibility is increased by several factors. The aim of this study was to determine the effects of clinical uterine findings and PBIE therapies, respectively, on pregnancy rate in mares. The analysis included records from 220 mares (390 cycles) inseminated at an artificial insemination (AI) center in Switzerland. Gynecological examinations were performed repeatedly before and after AI to determine cervical tone, uterine edema, and intrauterine fluid accumulation. Pregnancy rate was lower (p < 0.001) in barren mares compared to mares of other reproductive status. A more flaccid cervix (p = 0.009) was observed at the time of ovulation in pregnant cycles, but there was no difference (p > 0.05) regarding uterine edema. Intrauterine fluid accumulation reduced pregnancy rate (p = 0.002). Oxytocin administration had beneficial effects on pregnancy rate (p = 0.015), especially for barren mares, while uterine lavage did not have any effect (p > 0.05). The results show that cervical tone and intrauterine fluid accumulation, but not its degree, are useful parameters for assessment of fertility in mares. Oxytocin treatment improved pregnancy rates in mares with PBIE while uterine lavage had a limited effect.

Effects of two protocols of ovulation synchronization on corpus luteum size and blood flow, progesterone concentration, and pregnancy rate in beef heifers

The objective of this study was to evaluate the effect of 7-day estradiol-progesterone-based [Treat(C)] and 5-day Co-Synch plus progesterone [Treat(Co-Sy)] protocols on ovulation time, pre-ovulatory follicle diameter, corpus luteum (CL) size and blood flow, progesterone (P4) concentration and pregnancy rate (PR) in beef heifers. In Experiment 1, a crossover design was applied (n = 9). For Treat(C), a progesterone intravaginal (PI) device was inserted, plus 2 mg of estradiol benzoate (day 0). On day 7, 500 µg of cloprostenol plus 0.5 mg of estradiol cypionate were administered, and PI was removed. For Treat(Co-Sy), on day 0, a PI was inserted plus 100 µg gonadotropin-releasing hormone (GnRH). On day 5, PI was removed, plus 500 µg of cloprostenol and 100 µg of GnRH were administered at 69–70 h later. From day one to ovulation day, dominant follicle was evaluated by ultrasonography. On days 4 and 8 post-ovulation, CL was evaluated by color Doppler, and P4 concentration was determined by chemiluminescence. In Experiment 2, a split-plot experimental design was used. Protocols followed were the same as in Experiment 1 [Treat(C); n = 310 and Treat(Co-Sy); n = 314]. Heifers were fixed-time artificially inseminated. Pregnancy was determined on day 41. In Experiment 1, the interval between PI removal and ovulation time was different between protocols (P < 0.01). In addition, P4 concentration was related to the CL size (P < 0.001), CL blood flow (P < 0.01) and protocols (P < 0.03). In Experiment 2, PR did not differ between protocols.

The sperm-interacting proteome in the bovine isthmus and ampulla during the periovulatory period

BackgroundSpermatozoa interact with oviduct secretions before fertilization in vivo but the molecular players of this dialog and underlying dynamics remain largely unknown. Our objectives were to identify an exhaustive list of sperm-interacting proteins (SIPs) in the bovine oviduct fluid and to evaluate the impact of the oviduct anatomical region (isthmus vs. ampulla) and time relative to ovulation (pre-ovulatory vs. post-ovulatory) on SIPs number and abundance.MethodsPools of oviduct fluid (OF) from the pre-ovulatory ampulla, pre-ovulatory isthmus, post-ovulatory ampulla, and post-ovulatory isthmus in the side of ovulation were collected from the slaughterhouse. Frozen-thawed bull sperm were incubated with OF or phosphate-buffered saline (control) for 60 min at 38.5 °C. After protein extraction and digestion, sperm and OF samples were analyzed by nanoLC-MS/MS and label-free protein quantification.ResultsA quantitative comparison between proteins identified in sperm and OF samples (2333 and 2471 proteins, respectively) allowed for the identification of 245 SIPs. The highest number (187) were found in the pre-ovulatory isthmus, i.e., time and place of the sperm reservoir. In total, 41 SIPs (17%) were differentially abundant between stages in a given region or between regions at a given stage and 76 SIPs (31%) were identified in only one region × stage condition. Functional analysis of SIPs predicted roles in cell response to stress, regulation of cell motility, fertilization, and early embryo development.ConclusionThis study provides a comprehensive list of SIPs in the bovine oviduct and evidences dynamic spatio-temporal changes in sperm-oviduct interactions around ovulation time. Moreover, these data provide protein candidates to improve sperm conservation and in vitro fertilization media.

Synchronization of the ovulation and copulation timings increased the number of in vivo fertilized oocytes in superovulated female mice.

The number of sperm that reaches the oocytes in mammalian species is limited. In mice, 8-10 oocytes are ovulated, a similar number of sperm reaches the oocytes, and nearly all oocytes are fertilized via natural mating. Meanwhile, our improved superovulation technique (ultrasuperovulation: administration of inhibin antiserum and equine chorionic gonadotropin [IASe]) produced 100 oocytes from a single female C57BL/6 mouse but resulted in only approximately 20 fertilized oocytes via mating. We hypothesized that sperm shortage in the ampulla might cause this low fertilization rate. Mice were mated in the proestrus stage or after hormone injection, but ovulation timing was not considered. In clinical application, the rhythm method supports fertilization by testing the ovulation period and synchronizing the ovulation and copulation timings. Therefore, this study examined the effects of ovulation and copulation timings on in vivo fertilization in female mice with IASe. Synchronization of the ovulation and copulation timings increased fertilization efficiency in female mice with ultrasuperovulation. The number of embryos obtained post ovulation was three times higher than that obtained pre ovulation. This study suggests that synchronized ovulation and copulation timings improve the efficiency of in vivo fertilization in IASe-treated female mice. This technique can be used to produce genetically modified mice and develop technologies for infertility treatment.

The Effect of PMSG on Follicular Development and Ovulation Time of PGF2 Treated Awassi Ewes

The objective was to examine the effects of PMSG administration before or at the time of PGF2α injection on reproductive responses of ewes out-of-season. In late June and early July, 57 anestrus ewes were induced to estrus using CIDR-G devices for 12 days. Six days following device removal ewes were randomly allocated into three treatment groups and each received an i.m injection of 20mg PGF2α (day 0, 0 h). PMSG (500 IU) was administered either 24 h before (group A, n=20) or at (group B, n=19) the time of PGF2α injection. Group C ewes (n=18) served as control. Half of the ewes in each group were exposed to three intact rams at 0 h to be naturally mated and the other half were exposed to three aproned rams and inseminated 50-56 h following 0 h. Ewes were checked for breeding marks at 6-h intervals for 4 days. Progesterone levels from day –1 until day 20 were monitored. Occurrence of estrus was similar among ewes of the three treatment groups and averaged 79%. PMSG-treated ewes had shorter (P0.01) intervals to estrus and ovulation, and a higher ovulation rate than non-PMSG treated ewes. Pregnancy and lambing rates were similar among PMSG- and non-PMSG-treated ewes. Although reproductive responses were similar among artificially-inseminated and naturally-mated ewes, the latter had a higher (P0.05) lambing rate (14.3% vs 41.4%, respectively). Ewes inseminated close to the time of ovulation (7.7 h earlier) produced higher (P0.05) pregnancy rate than those inseminated at a wider interval from ovulation (16.7 h earlier). In conclusion, the PGF2α treatment given during luteal phase was effective in resetting subsequent cyclic activity of ewes. Although it did not increase the number of ewes detected in estrus, PMSG shortened intervals to estrus and ovulation, increased ovulation and induced–estrus pregnancy rates.

Progesterone circulation and follicular growth in adapted Bos taurus cows.

The creole breed Blanco Orejinegro (Bos taurus adapted) is an important animal genetic resource in Colombia. However, very little is known about the reproductive physiology of the breed. The objective was to determine the dynamics of progesterone circulation and follicular growth in Blanco Orejinegro cows throughout the estrous cycle. Fifteen cyclic Blanco Orejinegro cows were used and subjected to hormonal protocol for estrous and ovulation synchronization. Once the time of ovulation was identified by monitoring the ovarian dynamics with ultrasonography equipment. For description of the results, the mean was used as a measure of central tendency and the standard error of the mean. Statistical analysis was longitudinal descriptive. Blood samples were collected every 24 hr throughout the estrous cycle for serum quantification of progesterone (P4), monitoring of corpus luteum (CL) growth dynamics and follicular dynamics. It was possible to verify that 76.92% of the Blanco Orejinegro cows presented two follicular waves during the estrous cycle and the highest circulating levels of P4 (> 6.00 ng mL-1) were observed on the 14th day of the estrous cycle. It was concluded that the creole cows of the Blanco Orejinegro breed presented two follicular waves per estrous cycle. In addition to, the size of the CL was consistent with the secretion of progesterone presenting higher circulating levels at the end of the luteal phase.

In vivo embryo development in bitches inseminated laparoscopically after ovulation time estimated based on a single progesterone determination.

Logistic and economical limitations are often the causes of dog owners not accurately monitoring the estrous cycle and the optimal insemination time. The aim of this study was to evaluate in vivo early embryonic development in bitches, after the analysis of sequential vaginal cytologies associated to single progesterone measurement and single laparoscopic insemination with high quality semen (fresh and with high spermatozoa concentration) or low-quality semen (frozen/thawed and with low spermatozoa concentration) at 48 h post- ovulation time predicted on a single progesterone measurement. Ten bitches were inseminated with 250 x 106 fresh spermatozoa (80% motility), and ten with 80 x 106 frozen/thawed spermatozoa (60% motility) in the cranial part of each uterine horn. Seven days later, ovariohysterectomy was performed and the oviducts and uterine horns and body were flushed to recover embryos and unfertilized oocytes. In 80% of the bitches inseminated with fresh and 50% of bitches inseminated with frozen/thawed semen, embryos at 2 to 8 cells stage were recovered mostly from the, oviducts. This study indicates that pregnancies can be obtained with a single laparoscopic intrauterine insemination after single serum progesterone measurement, although with a low number of embryos. This result should be taken into account in case economic or logistic restrictions that affect the possibility of owners to plan an accurate monitoring of the optimal breeding time using fresh and frozen semen.

Importance of preovulatory estradiol on uterine receptivity and luteal function.

Animals that exhibited estrus had greater pregnancy success compared to animals that did not exhibit estrus before fixed-time AI (FTAI). Estradiol is synthesized in bovine ovarian follicles under gonadotropin regulation and can directly and indirectly regulate the uterine receptivity and luteal function. Estradiol concentrations at FTAI impacted oviductal gene expression and has been reported to play an important role in establishing the timing of uterine receptivity. These changes have been reported to impact uterine pH and sperm transport to the site of fertilization. After fertilization, preovulatory estradiol has been reported to improve embryo survival likely by mediating changes in uterine blood flow, endometrial thickness and changes in histotroph. Cows with greater estradiol concentrations at the time of GnRH-induced ovulation also had a larger dominant follicle size and greater circulating progesterone concentrations on day 7. Therefore, it is impossible to accurately determine the individual benefit of greater estradiol concentrations prior to ovulation and greater progesterone concentrations following ovulation to pregnancy establishment, as these two measurements are confounded. Research has indicated an importance in the occurrence and timing of increasing preovulatory concentrations of estradiol, but increasing estradiol concentrations by supplementation may not be sufficient to increase fertility. Increased production of estradiol by the preovulatory follicle may be required to enhance fertility through the regulation of sperm transport, fertilization, oviductal secretions, the uterine environment, and embryo survival.

Do sperm motility, morphology or associated factors predict the success rate of intrauterine insemination?

Objective: Infertility is a global health issue among couples of reproductive age. Intrauterine insemination (IUI) is a fertility treatment method where the processed sperms are deposited in the female uterus during the time of ovulation. The aim of this study was to explore the factors predicting the success rate of IUI (IUI-SR). Materials and Methods: A descriptive retrospective study was conducted analysing SFA and corresponding IUI reports of couples who underwent IUI from January 2017 to August 2021 at the Professorial unit of Colombo South Teaching Hospital, Sri Lanka. The data were analysed using SPSS version 22.0. Results: A total of 140 SFA and corresponding IUI reports were used. The IUI-SR was 18.57% (n=26). A significantly high IUI-SR was noted when the female partner aged &lt;30 years compared to &gt;30 years (p=0.000, OR=1.87), with first two IUI attempts compared to multiple IUI attempts (p=0.017, OR=0.271), pre-processed sperm concentration &gt;30M/ml compared to &lt;30M/ml (p=0.019, OR=3.12), and pre-processed sperm motility (progressive and non-progressive)&gt;40% compared to &lt;40% {p=0.039, OR=5.31). The period of abstinence (p-value=0.222), pre-processed sperm parameters such as total count (p-value=0.093), normal form morphology (p-value=0.082), viability (p-value=0.093), or post-processed sperm parameters such as concentration, progressive motility did not significantly influence the IUI-SR. Conclusion: A significantly high success rate of IUI can be achieved when the female partner is aged &lt;30 years and with the first two IUI attempts. Pre-processed sperm concentration &gt;30M/ml, and pre-processed sperm motility of progressive &gt;32% and non-progressive &lt;15% also predict a higher success rate of IUI.

Complete Cycle Mapping Using a Quantitative At-Home Hormone Monitoring System in Prediction of Fertile Days, Confirmation of Ovulation, and Screening for Ovulation Issues Preventing Conception.

Background and Objectives: To achieve pregnancy, it is highly beneficial to identify the time of ovulation as well as the greater period of fertile days during which sperm may survive leading up to ovulation. Confirming successful ovulation is also critical to accurately diagnose ovulatory disorders. Ovulation predictor kits, fertility monitors, and tracking apps are all available to assist with detecting ovulation, but often fall short. They may not detect the full fertile window, provide accurate or real-time information, or are simply expensive and impractical. Finally, few over-the-counter products provide information to women about their ovarian reserve and future fertility. Therefore, there is a need for an easy, over-the-counter, at-home quantitative hormone monitoring system that assesses ovarian reserve, predicts the entire fertile window, and can screen for ovulatory disorders. Materials and Methods: Proov Complete is a four-in-one at-home multihormone testing system that utilizes lateral flow assay test strips paired with the free Proov Insight App to guide testing of four hormones-FSH, E1G, LH, and PdG-across the woman's cycle. In a pilot study, 40 women (including 16 with a fertility-related diagnosis or using fertility treatments) used Complete for one cycle. Results: Here, we demonstrate that Proov Complete can accurately and sensitively predict ovarian reserve, detect up to 6 fertile days and confirm if ovulation was successful, in one easy-to-use kit. Ovulation was confirmed in 38 cycles with a detectable PdG rise. An average of 5.3 fertile days (from E1G rise to PdG rise) were detected, with an average of 2.7 days prior to LH surge. Ovulation was confirmed via PdG rise an average of 2.6 days following the LH surge. While 38/40 women had a PdG rise, only 22 had a sustained PdG level above 5 μg/mL throughout the critical implantation window, indicating ovulatory dysfunction in 16 women. Conclusions: Proov Complete can detect the entire fertile window of up to 6 fertile days and confirm ovulation, while also providing information on ovarian reserve and guidance to clinicians and patients.