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Recent methodological recommendations suggest the use of the "3-step method," consisting of calendar-based counting, urinary ovulation testing, and serum blood sampling, for the identification of subtle menstrual disturbances (SMDs). However, the use of the 3-step method is not always feasible, so a less demanding combination of calendar-based counting and urinary ovulation testing, that is, the 2-step method, may be a viable alternative. Purpose: To investigate the agreement between the 2- and 3-step methods for the detection of SMDs. Methods: Menstrual cycles (MCs, 98) of 59 athletes were assessed using the 2- and 3-step methods. Regular-length MCs (ie, ≥21 and ≤35 d) were classified as either having no SMD (luteal phase length ≥10 d, midluteal progesterone concentration ≥16 nmol·L−1, and being ovulatory) or having an SMD (eg, short luteal phase [<10 d], inadequate luteal phase [midluteal progesterone concentration <16 nmol·L−1], or being anovulatory). Method agreement was assessed using the McNemar test and Cohen kappa (κ). Results: Substantial agreement was observed between methods (κ =.72; 95% CI,.53–.91), but the 2-step method did not detect all MCs with an SMD, resulting in evidence of systematic bias (χ2 = 5.14; P =.023). The 2-step method detected 61.1% of MCs that had an SMD ([51.4, 70.8]), as verified using the 3-step method, and correctly identified 100% of MCs without an SMD. Conclusions: MCs classified as being disturbed using the 2-step method could be considered valid evidence of SMDs. However, MCs classified without SMDs do not definitively confirm their absence, due to the proven underdetection via the 2-step method. [ABSTRACT FROM AUTHOR]

The menstrual cycle is a loop involving the interplay of different organs and hormones, with the capacity to impact numerous physiological processes, including body temperature and heart rate, which in turn display menstrual rhythms. The advent of wearable devices that can continuously track physiological data opens the possibility of using these prolonged time series of skin temperature data to noninvasively detect the temperature variations that occur in ovulatory menstrual cycles. Here, we show that the menstrual skin temperature variation is better represented by a model of oscillation, the cosinor, than by a biphasic square wave model. We describe how applying a cosinor model to a menstrual cycle of distal skin temperature data can be used to assess whether the data oscillate or not, and in cases of oscillation, rhythm metrics for the cycle, including mesor, amplitude, and acrophase, can be obtained. We apply the method to wearable temperature data collected at a minute resolution each day from 120 female individuals over a menstrual cycle to illustrate how the method can be used to derive and present menstrual cycle characteristics, which can be used in other analyses examining indicators of female health. The cosinor method, frequently used in circadian rhythms studies, can be employed in research to facilitate the assessment of menstrual cycle effects on physiological parameters, and in clinical settings to use the characteristics of the menstrual cycles as health markers or to facilitate menstrual chronotherapy.

Embryo-maternal crosstalk is essential to establish pregnancy, with the equine embryo moving throughout the uterus on days 9-15 (ovulation = day 0) as part of this interaction. We hypothesized that the presence of a mobile embryo induces local changes in the gene expression of the endometrium. On Day 12, the endometrial transcripts were compared among three groups: uterine horn with an embryo (P+, n = 7), without an embryo (P-, n = 7) in pregnant mares, and both uterine horns of nonbred mares (NB, n = 6). We identified 1,101 differentially expressed genes (DEGs) between P+ vs. NB and 1,229 DEGs between P- vs. NB. The genes upregulated in both P+ and P- relative to NB were involved in growth factor pathway and fatty acid activation, while downregulated genes were associated with oxytocin signaling pathway and estrogen receptor signaling. Comparing the transcriptome of P+ to that of P-, we found 59 DEGs, of which 30 genes had a higher expression in P+. These genes are associated with regulating vascular growth factors and the immune system, all known to be essential in early pregnancy. Overall, this study suggests that the mobile embryo influences the endometrial gene expression locally.

Aminergic nuclei in mammals are generally composed of relatively small numbers of cells with broad projection patterns. Despite the gross similarity of many individual neurons, recent transcriptomic, anatomic and behavioral studies suggest previously unsuspected diversity. Smaller clusters of aminergic neurons in the model organism Drosophila melanogaster provide an opportunity to explore the ramifications of neuronal diversity at the level of individual cells. A group of approximately 10 tyraminergic/octopaminergic neurons innervates the female reproductive tract in flies and has been proposed to regulate multiple activities required for fertility. The projection patterns of individual neurons within the cluster are not known and it remains unclear whether they are functionally heterogenous. Using a single cell labeling technique, we show that each region of the reproductive tract is innervated by a distinct subset of tyraminergic/octopaminergic cells. Optogenetic activation of one subset stimulates oviduct contractions, indicating that the cluster as a whole is not required for this activity, and underscoring the potential for functional diversity across individual cells. Using whole cell patch clamp, we show that two adjacent and morphologically similar cells are tonically inhibited, but each responds differently to injection of current or activation of the inhibitory GluCl receptor. GluCl appears to be expressed at relatively low levels in tyraminergic/octopaminergic neurons within the cluster, suggesting that it may regulate their excitability via indirect pathways. Together, our data indicate that specific tyraminergic/octopaminergic cells within a relatively homogenous cluster have heterogenous properties and provide a platform for further studies to determine the function of each cell.

The African claw-toed frog, Xenopus laevis, is a well-established laboratory model for the biology of vertebrate oogenesis, fertilisation, and development at embryonic, larval, and metamorphic stages. For ovulation, X. laevis females are usually injected with chorionic gonadotropin, whereupon they lay typically hundreds to thousands of eggs in a day. After being rested for a minimum of three months, animals are re-used. The literature suggests that adult females can lay much larger numbers of eggs in a short period. Here, we compared the standard single ovulation protocol with a double ovulation protocol, in which females were ovulated, then re-ovulated after seven days and then rested for three months before re-use. We quantified egg number, fertilisation rate (development to cleavage stage), and corticosterone secretion rate as a measure of stress response for the two protocol groups over seven 3-month cycles. We found no differences in egg number-per-ovulation or egg quality between the groups and no long-term changes in any measures over the 21-month trial period. Corticosterone secretion was elevated by ovulation, similarly for the single ovulation as for the first ovulation in the double-ovulation protocol, but more highly for the second ovulation (to a level comparable to that seen following shipment) in the latter. However, both groups exhibited the same baseline secretion rates by the time of the subsequent cycle. Double ovulation is thus transiently more stressful/demanding than single ovulation but within the levels routinely experienced by laboratory X. laevis. Noting that stress hormone corticosterone/cortisol secretion is linked to physiological processes, such as ovulation, that are not necessarily harmful to the individual, we suggest that the benefits of a doubling in egg yield-per-cycle per animal without loss of egg quality or signs of acute or long-term harm may outweigh the relatively modest and transient corticosterone elevation we observed. The double ovulation protocol therefore represents a potential new standard practice for promoting the 3Rs (animal use reduction, refinement and replacement) mission for Xenopus research.

Background: Exogenous gonadotropin-controlled ovarian stimulation is the critical step in animal reproductive management, such as pig, sheep, bovine and other species. It helps synchronize ovulation or stimulate multiple ovulations. However, a number of evidence indicated an unexpected decrease in pregnancy outcomes following ovarian stimulation. This study aimed to explore the underlying mechanism of the pregnancy defect and develop a practical rescue strategy. Results: Compared with those in the control group, gilts that underwent ovarian stimulation showed a decrease in pregnancy rate, farrowing rate, and total number of piglets born. Stimulated gilts also showed an increase in estradiol (E2) levels. The supraphysiological E2 level was correlated with the decrease in the number of piglets born. Furthermore, we found that high levels of E2 impair uterine receptivity, as shown by the overproliferation of endometrial epithelial cells. In vitro mechanistic studies demonstrated that high levels of E2 hyperactivate FGF-FGFR-ERK signaling cascade in the uterine endometrium, and in turn induces overproliferation of endometrial epithelial cells. Of note, N-acetyl-L-cysteine (NAC) supplementation effectively inhibits ERK hyperphosphorylation and ameliorates endometrial epithelial overproliferation. Importantly, in vivo experiments indicated that dietary NAC supplementation, compared with ovarian stimulation group, improves the uterine receptivity in gilts, and significantly increases the pregnancy rate and total number of piglets born. Conclusions: Ovarian stimulation-induced supraphysiological levels of E2 impairs uterine receptivity by hyperactivating FGF-FGFR-ERK signaling cascade, thereby reducing pregnancy rate and litter size. Supplementing NAC to a conventional diet for gilts ameliorates hyperactivated ERK signaling and improves uterine receptivity, thus rescuing adverse pregnancy outcomes following ovarian stimulation. [ABSTRACT FROM AUTHOR]

Evaluating the breeding performance of cultivable fish using gonadotropin-releasing hormone (GnRH) analogues is crucial for optimizing reproductive efficiency and enhancing the sustainability of aquaculture practices. However, there is a lack of understanding regarding which GnRH analogue performs best under hatchery conditions for stinging catfish. Therefore, this study was conducted to assess the breeding performance of stinging catfish (Heteropneustes fossilis) using three commercially available GnRH analogs: Wova-FH, Ovaprim, and Easy-spawn. For this purpose, an experiment was set up in a commercial hatchery by dividing the samples into three groups, each treated with one of the analogs: Wova-FH, Ovaprim, or Easy-spawn. In the experiment, a ratio of 1.5:1 male to female was maintained, and 1 mL syringes were used to inject the analogs. The results showed that the spawning induction efficiency differed among the three inducing agents. Compared to Ovaprim and Easy-spawn, Wova-FH-treated H. fossilis exhibited higher breeding success in all measured aspects. Specifically, Wova-FH achieved a latency period of 8 h, an ovulation rate of 87.25%, a fertilization rate of 89.33%, a hatching rate of 88.85%, and an incubation period of 16 h. In comparison, Ovaprim and Easy-spawn had incubation periods of 18 h and 24 h, respectively. In Ovaprim-induced individuals, the latency period was approximately 8.30 h, with an ovulation rate of 82.08%, a fertilization rate of 86.75%, and a hatching rate of 85.97%. In contrast, the Easy-spawn-induced individuals had a latency period of 9 h, an ovulation rate of 27.50%, a fertilization rate of 27.10%, and a hatching rate of 26.15%. Significant differences (p < 0.05) were observed among the treatments in both the ovulation rate, fertilization rate, latency period incubation period, and hatching rate. The findings suggest that Wova-FH is a superior alternative to Ovaprim and Easy-spawn for GnRH analogs in the induced breeding programs of H. fossilis , offering optimal yield. [ABSTRACT FROM AUTHOR]

Adhesion G protein-coupled receptors are unique molecules. They are able to transmit classical signals via G protein activation as well as mediate functions solely through their extracellular N termini, completely independently of the seven transmembrane helices domain and the C terminus. This dual mode of action is highly unusual for G protein-coupled receptors and allows for a plethora of possible cellular consequences. However, the physiological implications and molecular details of this N terminus-mediated signaling are poorly understood. Here, we show that several distinct seven transmembrane helices domain-independent/ trans functions of the adhesion G protein-coupled receptor latrophilin homolog latrophilin-1 in the nematode Caenorhabditis elegans together regulate reproduction: sperm guidance, ovulation, and germ cell apoptosis. In these contexts, the receptor elicits its functions in a noncell autonomous manner. The functions might be realized through alternative splicing of the receptor specifically generating N terminus-only variants. Thus, our findings shed light on the versatility of seven transmembrane helices domain-independent/N terminus-only/ trans functions of adhesion G protein-coupled receptor and discuss possible molecular details. [ABSTRACT FROM AUTHOR]

Context. The use of progesterone vaginal implants in sheep is frequently associated with vaginitis and adherences; and can hamper fertility in estrus synchronization programs. Aims. The aim of this study was to characterize the plasma hormone profile induced by two injectable progesterone (iP4) formulations in ewes. Methods. In Experiment 1, ewes received 20 or 40 mg of an iP4, with a third group as a control. In Experiment 2, 75 or 150 mg of a long-acting iP4 were administered, again with a control group. Key results. In Experiment 1, progesterone concentrations remained at luteal levels for less than 24 h. The intervals from iP4 treatment to the onset of estrus and ovulation were greater treated than in control ewes (P < 0.01). The proportion of ewes that ovulated within 8 days after treatment was lower in ewes that received 40 mg iP4 than in control ewes (P < 0.05). In Experiment 2, mean progesterone concentrations remained at luteal levels for 120 h. The interval from iP4 administration to estrus was longer in 150 mg treated ewes than in control ewes (P < 0.01). The interval from treatment to ovulation was longer in ewes treated with 150 mg than 75 mg and control ewes < 0.05). The proportion of ewes that ovulated was lower at 150 mg (P < 0.05). Conclusions. The iP4 formula used in Experiment 1 could not maintain luteal levels for more than 24 h. The use of longacting iP4 maintained plasma progesterone concentrations above luteal levels for at least 5 days. The longacting treatment can therefore be tested for estrous synchronization treatments. Implications. The long-acting progesterone may be an alternative to short estrous synchronization protocols. [ABSTRACT FROM AUTHOR]

STUDY QUESTION What is the relative length variance of the luteal phase compared to the follicular phase within healthy, non-smoking, normal-weight, proven normally ovulatory, premenopausal women with normal-length menstrual cycles? SUMMARY ANSWER Prospective 1-year data from 53 premenopausal women with two proven normal-length (21–36 days) and normally ovulatory (≥10 days luteal) menstrual cycles upon enrollment showed that, despite 29% of all cycles having incident ovulatory disturbances, within-woman follicular phase length variances were significantly greater than luteal phase length variances. WHAT IS KNOWN ALREADY Many studies report menstrual cycle variability, yet few describe variability in follicular and luteal phase lengths. Luteal lengths are assumed 'fixed' at 13–14 days. Most studies have described follicular and luteal phase variability between -women. STUDY DESIGN, SIZE, DURATION This study was a prospective, 1-year, observational cohort study of relative follicular and luteal phase variability both between and within community-dwelling women with two documented normal-length (21–36 days) and normally ovulatory (≥10 days luteal phase) menstrual cycles prior to enrollment. Eighty-one women enrolled in the study and 66 women completed the 1-year study. This study analyzed data from 53 women with complete data for ≥8 cycles (mean 13). PARTICIPANTS/MATERIALS, SETTING, METHODS Participants were healthy, non-smoking, of normal BMI, ages 21–41 with two documented normal-length (21–36 days) and normally ovulatory (≥10 days luteal phase) menstrual cycles prior to enrollment. Participants recorded first morning temperature, exercise durations, and menstrual cycle/life experiences daily in the Menstrual Cycle Diary. We analyzed 694 cycles utilizing a twice-validated least-squares Quantitative Basal Temperature method to determine follicular and luteal phase lengths. Statistical analysis compared relative follicular and luteal phase variance in ovulatory cycles both between-women and within-woman. Normal-length cycles with short luteal phases or anovulation were considered to have subclinical ovulatory disturbances (SOD). MAIN RESULTS AND THE ROLE OF CHANCE The 1-year overall 53-woman, 676 ovulatory cycle variances for menstrual cycle, follicular, and luteal phase lengths were 10.3, 11.2, and 4.3 days, respectively. Median variances within-woman for cycle, follicular, and luteal lengths were 3.1, 5.2, and 3.0 days, respectively. Menstrual cycles were largely of normal lengths (98%) with an important prevalence of SOD: 55% of women experienced >1 short luteal phase (<10 days) and 17% experienced at least one anovulatory cycle. Within-woman follicular phase length variances were greater than luteal phase length variances (P  < 0.001). However, follicular (P  = 0.008) and luteal phase length (P  = 0.001) variances, without differences in cycle lengths, were greater in women experiencing any anovulatory cycles (n = 8) than in women with entirely normally ovulatory cycles (n = 6). LIMITATIONS, REASONS FOR CAUTION Limitations of this study include the relatively small cohort, that most women were White, initially had a normal BMI, and the original cohort required two normal-length and normally ovulatory menstrual cycles before enrollment. Thus, this cohort's data underestimated population menstrual cycle phase variances and the prevalence of SOD. WIDER IMPLICATIONS OF THE FINDINGS Our results reinforce previous findings that the follicular phase is more variable than the luteal phase in premenopausal women with normal-length and ovulatory menstrual cycles. However, our study adds to the growing body of evidence that the luteal phase is not predictably 13–14 days long. STUDY FUNDING/COMPETING INTEREST(S) This medical education project of the University of British Columbia was funded by donations to the Centre for Menstrual Cycle and Ovulation Research. The authors do not have any conflicts of interest to disclose. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

• In this study, the medicinal herbs with inductive effects on female reproductive system and their potential mechanisms of action are reviewed. • The clinical trials on the effects of herbal extracts on female reproduction system are also reviewed. • The need for conducting more scientific studies on the herbal extracts and standardization for development new supplements is discussed. Infertility is one of the significant global issues that affects approximately 15–17 % of couples worldwide, with around 50 % of cases being attributed to female infertility factors. The exploration of herbal extracts and their effects on female infertility has been limited, particularly regarding the underlying mechanisms beyond hormonal and oxidative stress influences. In this study, the herbal medicines with potential effects such as antioxidative properties, enhancement of insulin sensitivity, and modulation of the hypothalamic–pituitary–gonadal axis have been reviewed. Several herbal extracts were found to exhibit significant antioxidant properties and demonstrate phytoestrogenic effects on reproductive factors and hormonal levels. Antioxidants are essential in mitigating oxidative stress by neutralizing free radicals, which in turn helps to lower insulin resistance, total cholesterol, fat accumulation, and the proliferation of cancerous cells. Furthermore, this review highlights that certain parts of specific plants are rich in polyphenolic compounds, including isoflavones and flavonoids, along with other advantageous substances that support women's reproductive health. These compounds not only modulate female endocrine systems but also alleviate menopausal symptoms and effectively address a range of reproductive disorders, such as polycystic ovary syndrome (PCOS), premature ovarian failure (POF), endometriosis, hyperprolactinemia, and hypothalamic dysfunction. Turning to the other side, the plants and herbal extracts with suppressive effects on female fertility have been reviewed. These findings indicated that herbal extracts could be exploited to develop natural products as supplements for supporting the female reproductive system. [ABSTRACT FROM AUTHOR]

This study analyzed the inter‐annual variability in the reproductive dynamics of the Argentine hake from Patagonian waters during the last 20 years concerning the environmental conditions and the nutritional status of females. Macroscopic and histological information on gonadal maturity, female condition factor (K), and oceanographic data at different sampling sites throughout the studied region were obtained from research surveys carried out during the main spawning season of this species. Four stages, according to the maturity ovarian phases composition, were assigned annually at each sampling site to assess reproductive dynamics: vitellogenesis, ovulation, regression, and resting. The spatial pattern of inter‐annual variability in reproductive dynamics was described, and the influence of temperature and female condition on the probability of ovulation and regression was assessed using generalized linear models. The area with the lowest inter‐annual variability in the hake reproductive dynamics was observed between 43 and 45°S (50 to 80 m depth) in relation to ovulation events. The vitellogenesis stage was more frequently found adjacent to the reproductive area, whereas the regression was mainly observed in deeper waters. Both bottom and surface temperatures explained the ovulation and regression stages, showing a positive and negative relationship, respectively. Lower values of the K factor, associated with low food availability, were further linked to the occurrence of regression. Finally, it is worth noting that the relationship observed between the ovulation/spawning dynamics of Argentine hake and water temperature suggests that the reproductive success of this species could be affected in the future scenario of climate change. [ABSTRACT FROM AUTHOR]

The market for technology that tracks ovulation to promote conception is rapidly expanding in the United States, targeting the growing audience of technologically proficient, reproductive-age female consumers. In this narrative review, 23 different, nonprescription wearables and devices designed to help women track their fertile window were identified as currently, commercially available in the United States. The majority of these utilize measurements of basal body temperature or combinations of various urinary hormones. This clinical opinion characterizes the scant available research validating the accuracy of these technologies. It further examines research oversight, discusses the utility of these wearables and devices to consumers, and considers these technologies through an equity lens. The discussion concludes with a call for innovation, describing promising new technologies that not only harness unique physiologic parameters to predict ovulation, but also focus on cost-effectiveness with the hope of increasing access to these currently costly devices and wearables. [ABSTRACT FROM AUTHOR]

During ovulation, the apical wall of the preovulatory follicle breaks down to facilitate gamete release. In parallel, the residual follicle wall differentiates into a progesterone-producing corpus luteum. Disruption of ovulation, whether through contraceptive intervention or infertility, has implications for women's health. In this study, we harness the power of an ex vivo ovulation model and machine-learning guided microdissection to identify differences between the ruptured and unruptured sides of the follicle wall. We demonstrate that the unruptured side exhibits clear markers of luteinization after ovulation while the ruptured side exhibits cell death signals. RNA-sequencing of individual follicle sides reveals 2099 differentially expressed genes (DEGs) between follicle sides without ovulation induction, and 1673 DEGs 12 h after induction of ovulation. Our model validates molecular patterns consistent with known ovulation biology even though this process occurs in the absence of the ovarian stroma, vasculature, and immune cells. We further identify previously unappreciated pathways including amino acid transport and Jag-Notch signaling on the ruptured side and glycolysis, metal ion processing, and IL-11 signaling on the unruptured side of the follicle. This study yields key insights into follicle-inherent, spatially-defined pathways that underlie follicle rupture, which may further understanding of ovulation physiology and advance women's health. Molecular profiling of ex vivo ovarian follicles reveals key asymmetric pathways that underlie follicle rupture and luteinization during ovulation [ABSTRACT FROM AUTHOR]

Across taxa, breeding among close relatives is usually avoided because it incurs fitness costs to offspring. Incest is often averted through the dispersal of either sex from the natal area to breed. In some philopatric species, association among relatives extends into adulthood, and an ability to discriminate kin may be required for individuals to reduce inbreeding risk. Here, we aim to determine the mechanism of kin recognition for incest avoidance in the Damaraland mole-rat Fukomys damarensis, a cooperative breeder characterized by extreme reproductive skew. Pairs of opposite-sex adults were formed in the laboratory and, within pairs, genetic relatedness and degree of familiarity were manipulated through cross-fostering experiments. We found that unfamiliar pairs were more likely to engage in sexual behaviours and bred more successfully than familiar pairs, regardless of their genetic similarity. Females paired with unfamiliar males were also more likely to exhibit reproductive activation, characterized by increased levels of oestradiol and progesterone. This study shows that in Damaraland mole-rats, inbreeding avoidance can be achieved through a discrimination mechanism that relies on association during rearing, and that ovulation is induced by mating. This study advances our understanding of incest avoidance in species with constrained dispersal. [ABSTRACT FROM AUTHOR]

A successful control of sexual maturation is crucial for year-round production of lumpfish juveniles destined as cleaner fish in Atlantic salmon aquaculture. This study investigated the combined effects of photoperiod and temperature manipulations on sexual maturation and spawning in lumpfish females. Lumpfish juveniles were exposed to simulated natural and nine-month compressed annual photoperiods, with subsequent temperature elevation. Body weight (BW), condition factor (K), gonadosomatic index (GSI), ovarian development, plasma levels of 17β-estradiol (E2), testosterone (T) and 11-ketotestosterone (11-KT), and spawning were assessed. Compressing the natural photoperiod caused a clear increase and decrease in GSI, T, 11-KT and E2 towards and during the spawning period. Before the temperature elevation, GSI, T, 11-KT, E2 and ovarian development were advanced in the compressed photoperiod. After the temperature elevation, GSI, T, 11-KT and E2 fluctuated more in the compressed photoperiod, while in the natural photoperiod, E2 declined, and GSI, T and 11-KT increased. Spawning was advanced by 1 month in the compressed photoperiod compared to the natural photoperiod. Temperature elevation led to higher levels, earlier peaks and declines of T, 11-KT or E2 in both photoperiods, and advanced spawning by 1.5 months in the compressed photoperiod compared to the natural photoperiod. Temperature elevation also led to increased ovulation recruitment and increased cumulative weight of spawned eggs in the natural photoperiod. Compressing the natural photoperiod and elevating temperature can thus advance sexual maturation and spawning in lumpfish females. Due to the lower amounts of spawned egg weights in the high temperature compressed photoperiod, further studies on effects of photoperiod and timing of temperature manipulations on spawning, fecundity and egg quality could optimize the photothermal manipulations on lumpfish broodstock. [ABSTRACT FROM AUTHOR]

Background: Ovarian follicular fluid (FF) is a dynamic environment that changes with the seasons, affecting follicle development, ovulation, and oocyte quality. Cells in the follicles release tiny particles called extracellular vesicles (EVs) containing vital regulatory molecules, such as microRNAs (miRNAs). These miRNAs are pivotal in facilitating communication within the follicles through diverse signaling and information transfer forms. EV-coupled miRNA signaling is implicated to be associated with ovarian function, follicle and oocyte growth and response to various environmental insults. Herein, we investigated how seasonal variations directly influence the ovulatory and anovulatory states of ovarian follicles and how are they associated with follicular fluid EV-coupled miRNA dynamics in horses. Results: Ultrasonographic monitoring and follicular fluid aspiration of preovulatory follicles in horses during the anovulatory (spring: non-breeding) and ovulatory (spring, summer, and fall: breeding) seasons and subsequent EV isolation and miRNA profiling identified significant variation in EV-miRNA cargo content. We identified 97 miRNAs with differential expression among the groups and specific clusters of miRNAs involved in the spring transition (miR-149, -200b, -206, -221, -328, and -615) and peak breeding period (including miR-143, -192, -451, -302b, -100, and let-7c). Bioinformatic analyses showed enrichments in various biological functions, e.g., transcription factor activity, transcription and transcription regulation, nucleic acid binding, sequence-specific DNA binding, p53 signaling, and post-translational modifications. Cluster analyses revealed distinct sets of significantly up- and down-regulated miRNAs associated with spring anovulatory (Cluster 1) and summer ovulation–the peak breeding season (Clusters 4 and 6). Conclusions: The findings from the current study shed light on the dynamics of FF-EV-coupled miRNAs in relation to equine ovulatory and anovulatory seasons, and their roles in understanding the mechanisms involved in seasonal shifts and ovulation during the breeding season warrant further investigation. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the impact of sulpiride and PMSG hormone treatments on estrus and the number of offspring produced in female rats. Thirty mature rats were divided into three groups, each consisting of 10 females. The first group was treated intraperitoneally with sulpiride (0.25 mg/kg), the second group with PMSG hormone (20 IU/kg), and the third group with normal saline. Treatments were administered after the onset of estrus. Following treatment, natural mating occurred. The results of the study showed no significant differences between the PMSG hormone, sulpiride, and normal saline treatment groups regarding the number of females that showed estrus and mated. However, a significant difference (P < 0.05) was observed between the PMSG treatment group and the other groups with respect to the average number of embryos, which were 128, 75, and 55, respectively. The Luteinizing Hormone (LH) concentration was significantly higher (P < 0.05) in the sulpiride-treated group (1.44 ±0.12 ng/ml) compared to the PMSG hormone (1.23 ± 0.14 ng/ml) and normal saline treatment groups (0.76 ± 0.08 ng/ml). In conclusion, the application of PMSG was more effective in inducing ovulation and increasing the average number of offspring compared to sulpiride treatment in female rats. [ABSTRACT FROM AUTHOR]

Management of patients with congenital adrenal hyperplasia (CAH) poses challenges during pregnancy and prenatal stages, impacting fertility differently in men and women. Women with CAH experience menstrual irregularities due to androgen and glucocorticoid precursor interference with endometrial development and ovulation. Genital surgeries for virilization and urogenital anomalies further impact fertility and sexual function, leading to reduced heterosexual relationships among affected women. Fertility rates vary, with a lower prevalence of motherhood, primarily among those with classic CAH, necessitating optimized hormonal therapy for conception. Monitoring optimal disease control during pregnancy poses challenges due to hormonal fluctuations. Men with CAH often experience hypogonadotrophic hypogonadism and complications like testicular adrenal rest tissue, impacting fertility. Regular monitoring and intensified glucocorticoid therapy may restore spermatogenesis. Genetic counselling is vital to comprehend transmission risks and prenatal implications. Prenatal dexamethasone treatment in affected female fetuses prevents virilization but raises ethical and safety concerns, necessitating careful consideration and further research. The international "PREDICT" study aims to establish safer and more effective prenatal therapy in CAH, evaluating dosage, safety, and long‐term effects. [ABSTRACT FROM AUTHOR]

Simple Summary: This study evaluated peforelin as a potential alternative to PMSG for the induction of superovulation in C57BL/6J mice. The primary outcomes measured included oocyte yield, fertilization rates, and ovarian morphology. The results showed that although peforelin was less effective than PMSG in stimulating oocyte development and follicle differentiation, it did not adversely affect oocyte quality or ability to reach the blastocyst stage after in vitro fertilization. This study concludes that peforelin, particularly at 0.5 µg, is a promising alternative to PMSG, although further research is needed to optimize its use in the laboratory. This research supports the development of alternatives to PMSG in line with ethical animal welfare considerations. In biomedical research, ovulation induction is a critical step in the reproductive biology of laboratory animals. This study evaluates the efficacy of peforelin, a synthetic gonadotropin-releasing hormone (GnRH) analog, in comparison to pregnant mare serum gonadotropin (PMSG, synonym: eCG), traditionally used for ovulation induction in mice. PMSG is derived from the serum of pregnant horses, and its production is becoming increasingly problematic due to animal welfare concerns and regulatory restrictions. The aim of this study was, therefore, to evaluate an ethically acceptable and less invasive alternative to PMSG. Female C57BL/6J mice, aged 3–4 weeks, were divided into two groups to receive either peforelin at three different concentrations or PMSG, followed by an injection of human chorionic gonadotropin (hCG) to induce ovulation. Key outcomes included the number and quality of oocytes collected, fertilization rates, ovary morphology, and follicular differentiation. Although the number of oocytes was significantly lower in the peforelin cohort, the fertilization rate was high. Ovarian morphology was not significantly altered compared to the PMSG cohort. This study showed that peforelin is suitable for superovulation in mice. These results suggest that peforelin could be an ethically acceptable alternative to PMSG stimulation for inducing superovulation in mice. [ABSTRACT FROM AUTHOR]

Batch spawner fishes develop successive clutches of oocytes which allows them to participate in many reproductive cycles during their adult life (iteroparous) and spawn in multiple events within each breeding cycle. Here, ovarian follicular development was morpho‐functionally analyzed in females of the iteroparous batch spawner fish Gymnocorymbus ternetzi. To obtain better insights into the reproductive morpho‐physiology in batch spawners, the objective of this research was to analyze the dynamics of the follicular development, with its hormonal regulation between two active reproduction events. We found that over 16 days, follicles progressed asynchronously to chromatin nucleolus, Primary and Secondary growth stages of oogenesis with progressive secretion of 17β‐estradiol (E2). During the end of secondary growth, the increase in 17α,20β‐dihydroxy‐4‐pregnen‐3‐one (17,20β‐p) was measured relative to the maturation process of the ovarian follicles (e.g., nuclear migration and its rupture during the resumption of meiosis). Interestingly, an additional increase in E2 was observed after fish reproduction, probably related to the recruitment of new batch follicles for secondary growth. We also measured the high values of multiple condition factor post‐reproduction measurements, reflecting more energy invested during the pre‐reproductive process. We also quantified high concentrations of 17,20β‐p, probably related to the recruitment of a new batch of oogonia to meiosis, presumably secreted by post‐ovulatory follicles, after fish reproduction. We finally found that fish without exposure to reproductive stimulus developed a regression phase at day 24, characterized by massive follicle atresia, that allow them to recycle energy and constitutive materials of the follicles invested during oogenesis for another reproductive cycle. [ABSTRACT FROM AUTHOR]

Progestin-only pills (POPs) have emerged as a crucial contraceptive option for women, particularly those contraindicated to oestrogens. This opinion paper introduces two new indices, the Inhibition Ratio (I.R.) (cyclical and daily) and the Transformation Index (T.I.), to evaluate and compare the efficacy and clinical behaviour of modern POPs. The I.R. quantifies the ratio between the progestin dosage in a POP and the minimum dose required to inhibit ovarian function, providing insights into contraceptive efficacy. The T.I., on the other hand, assesses its clinical impact by considering the ratio between the total progestin dose and the dose required to induce endometrial luteinising changes. Both indices thus offer valuable tools for comparing progestins even at significantly different dosages and regimens, providing information on clinical characteristics and drug effects. The newest formulations of POPs (Desogestrel 28 and Drospirenone 24 + 4) have demonstrated higher I.R. and T.I. in comparison to older versions, indicating significant improvements in contraceptive efficacy and clinical impact with better menstrual cycle control. We believe that using these indices will ensure a more informed and personalised choice of progestin not only for contraceptive purposes but also for therapeutic use in gynaecology. The future goal is to develop other progestins with even more advantageous I.R. and T.I., ensuring the best contraceptive efficacy with fewer side effects, even in women at risk (obese, etc.). SHORT CONDENSATION: The Inhibition Ratio (I.R.) (cyclical and daily) and the Transformation Index (T.I.) are two new proposed indexes to evaluate and compare the efficacy and clinical behaviour of modern and future POPs. [ABSTRACT FROM AUTHOR]

The roles of initially kisspeptin and subsequently neurokinin B pathways in the regulation of human reproduction through the control of GnRH secretion were first identified 20 years ago, as essential for the onset of puberty in both boys and girls. Within that short time we already now have the first licence for clinical use for a neurokinin antagonist in a related indication, for menopausal vasomotor symptoms. Between these two markers of the start and end of the reproductive lifespan, it is clear that these pathways underlie many of the aspects of the hypothalamic regulation of reproduction which had hitherto been enigmatic. In this review, we describe the data currently available from studies designed to elucidate the roles of kisspeptin and neurokinin B in human ovarian function, specifically the regulation of follicle development leading up to ovulation, and in the control of the mid‐cycle GnRH/LH surge that triggers ovulation. These studies, undertaken with only very limited pharmacological tools, provide evidence that the neurokinin B pathway is important in controlling the hypothalamic contribution to the precise gonadotropic drive to the ovary that is necessary for mono‐ovulation, whereas the switch from negative to positive estrogenic feedback results in kisspeptin‐mediated increased GnRH secretion. Potential therapeutic opportunities in conditions characterised by disordered hypothalamic/pituitary function, polycystic ovary syndrome, and functional hypothalamic amenorrhoea, and in the induced LH surge that is a necessary part of IVF treatment are discussed. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Our overarching objective was to characterize associations between genomic merit for fertility and the reproductive function of lactating dairy cows in a prospective cohort study. In this manuscript, we present results of the association between genomic merit for fertility and indicators of metabolic status and inflammation, uterine health, endocrine status, response to synchronization, and estrous behavior in dairy cows. Lactating Holstein cows entering their first (n = 82) or second (n = 37) lactation were enrolled at parturition and fitted with an ear-attached sensor for automated detection of estrus. Ear-notch tissue samples were collected from all cows and submitted for genotyping using a commercial genomic test. Based on genomic PTA values for daughter pregnancy rate (gDPR), cows were classified into a high (Hi-Fert; gDPR >0.6; n = 36), medium (Med-Fert; gDPR −1.3 to 0.6; n = 45), or low (Lo-Fert; gDPR <−1.3; n = 38) group. At 33 to 39 DIM, cohorts of cows were enrolled in the Presynch-Ovsynch protocol for synchronization of estrus and ovulation. Body weights, BCS, and uterine health measurements (i.e., vaginal discharge, uterine cytology) were collected from parturition to 60 DIM, and milk yield was collected through 90 DIM. Blood samples were collected weekly through 3 wk of lactation for analysis of BHB, nonesterified fatty acids (NEFA), and haptoglobin plasma concentrations. Body weight, BCS, NEFA, BHB, and haptoglobin were not associated with fertility groups from 1 to 9 wk after parturition. The proportion of cows classified as having endometritis at 33 to 36 DIM tended to be greater for the Lo-Fert than the Hi-Fert group. The proportion of cows that resumed cyclicity did not differ at any time point evaluated, and there were no significant associations between probability or duration and intensity of estrus with fertility group. Cows of superior genetic merit for fertility were more likely to ovulate, have a functional corpus luteum, have greater circulating progesterone, and have larger ovulatory size than cows of inferior fertility potential at key time points during synchronization of estrus and ovulation. Despite observing numerical differences with potential performance consequences for the proportion of cows that responded to synchronization of ovulation and were both cyclic and responded to the Ovsynch portion of the synchronization protocol, we did not observe significant differences between fertility groups. Although not consistent and modest in magnitude, the collective physiological and endocrine differences observed suggested that cows of superior genetic fertility potential might have improved reproductive performance, at least in part, because of modestly improved endocrine status, uterine health, and ability to ovulate. [ABSTRACT FROM AUTHOR]

Delayed fertilization leads to the ageing of post-ovulatory oocytes and reduces the developmental competence of arising embryos. Little information is available about the molecular processes during fish oocyte ageing. The current study investigated the functional consequences of oocyte ageing in grass carp Ctenopharyngodon idella embryos. In addition, the dynamics of selected post-transcriptionally modified histones (acetylation of H3K9, H3K14, H4K5, H4K8, H4K12, and H4K16) were analyzed during oocyte ageing. Ovulated oocytes were aged in vitro for 4 h in the laboratory incubator at 20 °C and studied for selected post-translational modification of histones. In addition, histone acetyltransferase activity was investigated as an important regulator of histone acetylation modification. The results indicated a significant decrease in oocyte fertilizing ability through 1 h of post-ovulatory ageing, and a complete loss of egg fertilizing abilities was detected at 4-h aged oocytes. Furthermore, post-ovulatory oocyte ageing for 1 and 4 h led to decreased levels of H4K12 acetylation. The activity of histone acetyltransferases increased significantly after ageing of the oocytes for 30 h in vitro. This modification may partly contribute to explaining the failures of egg viability and embryo development in the offspring from the aged oocytes. The results are the first to report histone modifications as a crucial epigenetic regulator during oocyte ageing in fish and might also benefit other vertebrates. [ABSTRACT FROM AUTHOR]

Biochemical confirmation of ovulation typically involves measuring serum progesterone levels during the mid‐luteal phase. Alternatively, this information could be obtained by monitoring urinary excretion of conjugated metabolites of ovarian steroids such as pregnanediol 3‐glucuronide (PDG) using immunoassay techniques that have methodological limitations. The aim of the present study was to develop a mass spectrometry (MS)‐based method for the rapid and accurate measurement of urinary PDG levels in spot urine samples. A "dilute and shoot" ultra‐high‐performance liquid cromatography tandem mass spectrometry (UHPLC‐MS/MS) method was developed for measuring PDG urinary concentration with a 6‐min analysis time. The method underwent validation in accordance with ISO 17025 documentation for quantitative methods, proving an efficient separation of PDG from other structurally similar glucuro‐conjugated steroid metabolites and ensuring a sufficient sensitivity for detecting the target analyte at concentrations as low as 0.01 μg/mL. The validation protocol yielded satisfactory results in terms of accuracy, repeatability, intermediate precision, and combined uncertainty. Additionally, the stability of both the samples and calibration curves was also conducted. The application to real urine samples confirmed the method's capability to measure PDG levels throughout an entire menstrual cycle and detecting ovulation. The rapidity of the analytical platform would therefore enable high throughput analysis, which is advantageous for large cohort clinical studies. [ABSTRACT FROM AUTHOR]

Platelet-activating factor (PAF) has been implicated in a number of reproductive processes ranging from ovulation to embryo motility but has not been widely explored in the mare. To identify the presence and examine the role of PAF in the equine periconception processes, targeted mass spectrometry coupled with chromatographic separation was performed on equine follicular fluid (FF), and PAF was quantitatively detected. Subsequently, untargeted high-resolution mass spectrometry-based lipidomic analysis was carried out to quantify PAF in differentsized pre-ovulatory follicles, whereby different molecular species of PAF, PAF (14:0) and PAF (16:1), were both seen to be increasing with follicle diameter. These findings suggest that PAF within FF is increasing as preovulatory follicles approach ovulation. Additionally, immunofluorescence staining identified the PAF receptor in the luminal pericellular, apical, and basal aspect of equine oviductal epithelial cells. Lastly, an equine oviductal epithelial organoid model was generated and showed that the addition of PAF significantly increased the ciliary beat frequency (CBF) (Hz), an action consistent with a role for PAF in embryo migration. It is proposed that the local action of PAF on the ciliated cells of the oviduct propels both the oocyte and the conceptus towards the uterus. In the mare, it appears that PAF is a contributor during the periconception period, potentially being a mediator in the mechanisms of ovulation and in the dialogue of very early pregnancy. [ABSTRACT FROM AUTHOR]

Polycystic ovary syndrome (PCOS) is one of the major endocrine disorders faced by 5-10% of women in their childbearing period. Characterized by raised androgen levels, irregularities in menses and/or polycystic ovaries, the best description that can be linked to PCOS would then be a syndrome including hyperandrogenism, chronic anovulation, and polycystic ovaries. PCOS is a heterogeneous condition associated with many potentially co-occurring disorders, including insulin resistance, obesity and infertility, type 2 diabetes mellitus, cardiovascular disease and even endometrial cancer. The exact causes of this syndrome are yet unknown, though genes, metabolism, malfunction of the endocrine system, and environmental factors are claimed to be involved. Hyperandrogenism manifests itself in the difficulty of follicles to grow and develop, forming small cysts in the ovaries, creating anovulation, contributing to menstrual changes. Modest amounts of weight loss, such as 5%, can be associated with improved endocrine profile and increased likelihood of ovulation and pregnancy. PCOS is treated by means of lifestyle modifications in the form of diet and exercise, medications like clomiphene citrate or metformin, and surgical measures like laparoscopic ovarian drilling only in a few. Diagnosis at an early stage and early institution of treatment are very important to prevent or at least delay the long-term complications of PCOS. With proper management, most women can achieve regularity in menses, ovulation, and finally, successful pregnancy. [ABSTRACT FROM AUTHOR]

AbstractOn 19 July, 2024, at the age of almost 105 years, Joseph W. Goldzieher, the last survivor of the group of pioneers who created oral contraception, peacefully passed away. Here we briefly reconstruct the salient points in his long, productive life, and highlight his achievements in the development of hormonal contraception. His work is indissolubly enshrined in the complex history of hormonal contraception, from the first, fundamental observations, to the first clinical trials, both in the form of combined oestrogen-progestin oral pills and long-acting injectable contraceptives. After Pincus and his Group created an oral contraceptive containing an oestrogen and a progestin, Goldzieher was the second international scientist to conduct clinical trials of the new modality. He teamed-up with investigators in Mexico creating a fruitful, long-lasting collaboration. They produced evidence that ovulation inhibition could be achieved with all the progestins used at the time. Of importance, he was among the first to explore the possibility of using oestrogens to block ovulation, and developed the concept of sequential contraception. For all this lifetime of work, we believe he deserves to be named a ‘giant in reproductive endocrinology’. [ABSTRACT FROM AUTHOR]

The objective of study was to characterize HPV in vaginal samples from women being seen at the Center for Reproductive Medicine and Infertility at Weill Cornell Medicine before and following ovarian stimulation. A total of 29 women made samples available for analysis by viral metagenomics. Eighteen women were HPV-positive, six (33.3%) at their initial visit and 15 (83.3%) following hormone stimulation (p = 0.0059). Pairwise comparison of nucleotide sequences and phylogenetic analysis showed the classification sequences into two genera: Alphapapillomavirus and Gammapapillomavirus. Sequences were from 8 HPV types: HPV 51 (n = 2), HPV 68 (n = 1), HPV 83 (n = 9), HPV 84 (n = 2), HPV 121 (n = 6), HPV 175 (n = 1) and HPV 190 (n = 1). Additionally, C16b and C30 likely represent new types. In summary, multiple HPV types are present in the vagina of reproductive age women and are induced by hormone used to stimulate ovulation. [ABSTRACT FROM AUTHOR]

Ovulation is critical for sexual reproduction and consists of the process of liberating fertilizable oocytes from their somatic follicle capsules, also known as follicle rupture. The mechanical force for oocyte expulsion is largely unknown in many species. Our previous work demonstrated that Drosophila ovulation, as in mammals, requires the proteolytic degradation of the posterior follicle wall and follicle rupture to release the mature oocyte from a layer of somatic follicle cells. Here, we identified actomyosin contraction in somatic follicle cells as the major mechanical force for follicle rupture. Filamentous actin (F-actin) and nonmuscle myosin II (NMII) are highly enriched in the cortex of follicle cells upon stimulation with octopamine (OA), a monoamine critical for Drosophila ovulation. Pharmacological disruption of F-actin polymerization prevented follicle rupture without interfering with the follicle wall breakdown. In addition, we demonstrated that OA induces Rho1 guanosine triphosphate (GTP)ase activation in the follicle cell cortex, which activates Ras homolog (Rho) kinase to promote actomyosin contraction and follicle rupture. All these results led us to conclude that OA signaling induces actomyosin cortex enrichment and contractility, which generates the mechanical force for follicle rupture during Drosophila ovulation. Due to the conserved nature of actomyosin contraction, this work could shed light on the mechanical force required for follicle rupture in other species including humans. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the superestimulatory and superovulatory responses of cattle treated with corifollitropin-alpha, a long-acting human recombinant FSH (rhFSH). In the first and second experiments, we used Nelore (Bos indicus) heifers previously submitted to follicular wave suppression by active immunization against GnRH. In Experiment 1 (a dose-response study), heifers (n = 20) were randomly allocated into five groups, which received placebo (saline) or a single sc dose of 7.5, 15.0, 22.5 or 30.0 μg rhFSH. The heifers were subjected to daily ovarian scan and blood sampling during 11 days. We observed group, time, and group x time effects (P< 0.0001) for both average follicle size and circulating FSH concentrations, with a strong correlation (R = 0.82, P< 0.0001) between the area under curve (AUC) for both parameters. The peak concentration of FSH 24h after treatment and average follicle size at all timepoints, however, were similar (P> 0.05) between groups 22.5 and 30.0 μg. In Experiment 2, heifers (n = 18) were allocated into three groups, which received (0h) either placebo (control), 25 μg rhFSH or 130 mg pFSH (Folltropin). There was no difference (P> 0.05) in average follicle size at any moment, as well as in intrafollicular E2 at 120h or in plasma P4 seven days later between groups rhFSH and pFSH. In Experiment 3, cycling Nelore heifers (n = 20) were subjected to a wave synchronization protocol and superovulated (day 0) using a standard pFSH protocol (120 mg split in eight decreasing im doses) or with a single sc injection of 20 μg rhFSH. The number of follicles >7 mm on day 4 did not differ (P= 0.4370). Heifers receiving rhFSH had greater average follicle size on day 4 (P= 0.0005), ovulation rate (P< 0.0001), and number of CL (P= 0.0155), as well as a trend towards a greater number of ova (P= 0.07) and viable embryos (P= 0.0590). In Experiment 4, superovulation was induced with a single sc injection of 25 μg rhFSH in Girolando and Nelore cows and heifers (n = 20). None of the embryo yield endpoints differed between the two breeds (P> 0.05). In conclusion, cattle superstimulation and superovulation can be successfully induced with a single dose of a long-acting rhFSH (corifollitropin-alpha). • Cattle respond to superstimulation with corifollitropin-alpha in a dose-dependent manner. • Ovarian superovulation can be induced with 20–25 mcg of corifollitropin-alpha. • Corifollitropin-alpha is detected in circulating serum up to 11 days after treatment. [ABSTRACT FROM AUTHOR]

The bovine embryo production industry has seen significant growth over the past two decades, particularly in the production of in vitro produced embryos. This growth, driven by advancements in cryopreservation, in vitro culture mediums, ovum pick-up (OPU) procedures, ultrasonography devices, and embryo transfer (ET) has been notable. Particularly, ET is crucial for disseminating high genetic merit and amplifying foreign breeds by importing frozen embryos. This retrospective study aimed to assess factors affecting conception per embryo transfer (CPET) in Holstein-Friesian cattle in South Korea from October 2008 to July 2022. We evaluated type of embryo breed, type of embryo production (fresh and frozen; in vitro and in vivo production), recipient conditions including estrus type, corpus luteum quality, parity (nulliparous heifers, primiparous, and multiparous cows), and the daily mean temperature-humidity index (THI) as an index for heat stress. Type of embryo breed and estrus had no significant impact on CPET. However, we observed higher CPET in recipients with good quality corpus luteum, nulliparous heifers, and surrogates receiving fresh in vitro and frozen in vivo embryos. Importantly, CPET was not adversely affected by mild heat stress conditions (up to daily mean THI 76), indicating that using frozen in vivo embryos produced by multiple ovulation embryo transfer and fresh in vitro embryos by OPU-ET can help alleviate the subfertility issues in dairy cattle caused by global warming in Korea. • Recipient parity and corpus luteum were significant determinants of conception per embryo transfer (CPET) in Holstein cattle • The temperature-humidity index, a measure of heat stress, did not significantly affect CPET. • Embryo type significantly influenced CPET, • Selecting recipients by parity and CL quality is crucial for ET success, offering an effective AI alternative in heat-stressed environments. [ABSTRACT FROM AUTHOR]

Two experiments evaluated the effect of different hormonal treatments to synchronize follicle wave emergence on follicle dynamics and pregnancies per AI (P/AI) in estradiol (E2)/progesterone (P4) timed-AI (TAI) protocols in lactating dairy cows. In Experiment 1, lactating, primiparous Holstein cows (n = 36) received a P4 releasing device (Day 0) and were allocated at random to one of the following three treatment groups: Group EB received 2 mg E2 benzoate (EB) intramuscularly (i.m.), Group EB + GnRH received 2 mg EB+20 μg buserelin (GnRH) i.m., or Group EB + P4 received 2 mg EB + 100 mg of injectable P4 (iP4) in oil i.m. All cows received 0.150 mg D-Cloprostenol on Days 7 and 8 followed by P4 device removal, 400 IU eCG and 1 mg ECP on Day 8. Daily ultrasound examinations revealed that although the interval from P4 device removal to ovulation was not affected by treatment, cows that received EB + GnRH had an earlier (P < 0.05) emergence of the new follicular wave (Day 2.6 ± 0.2) than the other two treatment groups (Days 3.5 ± 0.3 and 6.1 ± 0.3, for EB and EB + P4, respectively). In Experiment 2, 808 lactating cows were assigned randomly to the three treatments evaluated in Experiment 1, and all the cows were TAI to determine P/AI. Cows in the EB + GnRH group had greater P/AI (57.4 %, P < 0.01) than those in the EB (44.6 %) or EB + P4 (45.7 %) groups. In conclusion, the administration of GnRH, but not iP4, on the day of insertion of a P4 device improves P/AI in lactating dairy cows synchronized for TAI with an estradiol/P4-based protocol. • The addition of GnRH or injectable P4 to synchronize follicular wave emergence in an estradiol/P4-based protocol for TAI was evaluated in dairy cows. • The combination of EB + GnRH at P4 device insertion synchronized follicle wave emergence and improved P/AI following TAI. • Adding injectable P4 to EB at P4 device insertion did not improve follicle wave synchronization or P/AI compared to EB given alone. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of different doses of equine chorionic gonadotropin (eCG; 200 and 300 IU) administered at the end of a fixed-time artificial insemination (FTAI) treatment protocol on ovulation, pregnancy, and twin rates in Bos taurus beef heifers. In addition, pregnancy losses in heifers with singleton and twin pregnancies were determined. A total of 2382 Angus heifers treated with a 6-day estradiol/progesterone-based protocol for FTAI (J-Synch protocol) were randomly allocated to two experimental groups to receive 200 or 300 IU of eCG administered intramuscularly at the time of intravaginal progesterone device removal; FTAI was performed from 60 to 72 h after device removal. The pregnancy rate did not differ (P = 0.89) between the 200 and 300 IU eCG groups. The number of corpus luteum induced by both eCG doses was determined by ultrasonographic examination 14 days after insemination and those treated with 300 IU of eCG had a greater double ovulation rate (P < 0.05). In addition, 300 IU eCG treated heifers had a higher twinning rate on day 30 of gestation (P < 0.05) and parturition (P < 0.05). Pregnancy losses from 30 days of gestation to calving did not differ between heifers treated with 200 and 300 IU of eCG (P = 0.70). However, regardless of the experimental group, heifers bearing twins had greater pregnancy losses than heifers with singletons (P < 0.05). In conclusion, reducing the dose of eCG from 300 to 200 IU under FTAI treatment protocol decreases double ovulation and twinning rates, maintaining a similar pregnancy rate in heifers. Nulliparous cows carrying two fetuses suffer greater pregnancy losses than cows with singletons. • Different doses of eCG were evaluated in a progesterone-based protocol for FTAI. • Reducing from 300 to 200 IU eCG maintained similar P/AI. • Twinning rate was lower with 200 IU eCG. • Those heifers bearing twins, suffer greater pregnancy losses than singletons. [ABSTRACT FROM AUTHOR]

Fetal age in Quarter Horses can be predicted within 2 weeks from 100- to 200- days of gestation using femur length, biparietal diameter (cranium diameter) and eye approximated volume. However, as pregnancy advances, the femur and cranium become too large to be imaged in their entirety using ultrasound and the corresponding biometric parameters can no longer be measured. In this longitudinal study, the proximal phalanx (P1) was evaluated as a novel biometric parameter for late gestation to predict fetal age and bone maturation. Transrectal ultrasound was performed in ten pregnant mares with known ovulation dates, every two weeks from 240- days of gestation until parturition. P1 was imaged in 69 % of the examinations. Inability to image P1 was due to obstructive positioning such as carpal or fetlock flexion, or posterior presentation of the fetus. Advancing fetal age did not affect visibility of P1. P1 length correlated significantly with days of gestation and a correlation equation was established: y = 0.3837x -69.55 where y is the predicted value of P1 length and x is the day of gestation (with day 0 being the day of ovulation). When P1 length was equal to or larger than the width of the ultrasound image (52.5 mm), 90 % of mares (9/10) were above 300- days of gestation. Ossification of the proximal and distal epiphysis of P1 typically appeared between 277- and 303 -days of gestation (mean: 288 days). The proximal epiphysis did not close before parturition whereas the distal one closed between 306- and 333-days of gestation (mean: 320 days). P1 epiphyseal appearance and closure occurred chronologically reflecting bone maturation. Radiographic findings at birth and prenatal ultrasound findings were in agreement, apart from timing of P1 distal epiphyseal closure. In conclusion, P1 length can be used as a new fetal biometric parameter to assess fetal age and growth after 240- days of gestation. The knowledge of P1 bone maturation process in utero as a marker for fetal bone development, may also be valuable in clinical decision-making when considering inducing parturition in the mare. [ABSTRACT FROM AUTHOR]

Ovulation is vital for successful reproduction. Following ovulation, cumulus cells and oocyte are released, while mural granulosa cells (mGCs) remain sequestered within the post‐ovulatory follicle to form the corpus luteum. However, the mechanism underlying the confinement of mGCs has been a longstanding mystery. Here, in vitro and in vivo evidence is provided demonstrating that the stiffening of mGC‐layer serves as an evolutionarily conserved mechanism that prevents mGCs from escaping the post‐ovulatory follicles. The results from spatial transcriptome analysis and experiments reveal that focal adhesion assembly, triggered by the LH (hCG)‐cAMP‐PKA‐CREB signaling cascade, is necessary for mGC‐layer stiffening. Disrupting focal adhesion assembly through RNA interference results in stiffening failure, mGC escape, and the subsequent development of an abnormal corpus luteum characterized by decreased cell density or cavities. These findings introduce a novel concept of "mGC‐layer stiffening", shedding light on the mechanism that prevents mGC escape from the post‐ovulatory follicle. [ABSTRACT FROM AUTHOR]

Background: Alpacas have reproductive traits such as induced ovulation and a higher gestation rate in the left uterine horn (LUH). Additionally, low fertility and high embryonic mortality are significant challenges in alpaca breeding. To address these issues, it is essential to study the histological changes occurring in the uterine wall during day 8 of the luteal phase (LP). Aim: This research aims to describe these changes in alpacas with induced ovulation using GnRH or copulation. Methods: The study was conducted on 8 sexually mature fertile alpacas with a preovulatory follicle of = 7 mm. Ovulation was induced with GnRH (G1, n = 3) and natural mating' (G2, n = 5), confirmed by ultrasound showing the disappearance of the follicle and formation of the corpus luteum (CL). On day 8 of the LP, samples of the uterine wall from the right and LUHs were obtained through a midline laparotomy. A uterine lavage with PBS was also performed, and no embryo-ova was found. The tissues were fixed, processed, and stained with Hematoxylin and Eosin. Measurements of the myometrium and endometrium, the area of the superficial and deep endometrial glands, the height of the gland cells, and the height of the endometrial mucosal cells were performed using microscopy and software. The measurements were taken in microns (um), from 12 different photographs per animal. Results: In G2 (copulation), greater thickness of the endometrium and myometrium, as well as a larger area of the superficial glands and cell height, were observed (p < 0.005). Additionally, the area of the superficial glands in the left horn was greater compared to the right. Conclusion: The thickness of the myometrium and endometrium, and the area of the superficial glands of the LUH in alpacas during the LP (day 8), induced by copulation (G2), show better development. This research provides new insights into changes in the histomorphometry of the alpacas' uterus during this stage and is the first report on this species. [ABSTRACT FROM AUTHOR]

Reproduction in all mammalian species depends on the growth and maturation of ovarian follicles, that is, folliculogenesis. Follicular development can culminate with the rupture of mature follicles and the consequent expulsion of their oocytes (ovulation) or in atresia, characterized by the arrest of development and eventual degeneration. These processes are regulated by different neuroendocrine signals arising at different hypothalamic nuclei, including the suprachiasmatic nucleus (SCN). In the later, the activation of muscarinic receptors (mAChRs) and nicotinic receptors (nAChRs) by acetylcholine is essential for the regulation of the pre‐ovulatory signals that stimulate the rupture of mature follicles. To evaluate the participation of the nAChRs in the SCN throughout the oestrous cycle in the regulation of the hypothalamic–pituitary–ovarian axis. For this purpose, 90‐day‐old adult female rats in metoestrus, dioestrus, proestrus or oestrus were microinjected into the left‐ or right‐SCN with 0.3 μL of saline solution as vehicle or with 0.225 μg of mecamylamine (Mec), a non‐selective antagonist of the nicotinic receptors, diluted in 0.3 μL of vehicle. The animals were sacrificed when they presented vaginal cornification, indicative of oestrus stage, and the effects of the unilateral pharmacological blockade of the nAChRs in the SCN on follicular development, ovulation and secretion of oestradiol and follicle‐stimulating hormone (FSH) were evaluated. The microinjection of Mec decreased the serum levels of FSH, which resulted in a lower number of growing and healthy follicles and an increase in atresia. The higher percentage of atresia in pre‐ovulatory follicles was related to a decrease in the number of ova shed and abnormalities in oestradiol secretion. We also detected asymmetric responses between the left and right treatments that depended on the stage of the oestrous cycle. The present results allow us to suggest that during all the stages of the oestrous cycle, cholinergic signals that act on the nAChRs in the SCN are pivotal to modulate the secretion of gonadotropins and hence the physiology of the ovaries. Further research is needed to determine if such signals are generated by the cholinergic neurons in the SCN or by cholinergic afferents to the SCN. [ABSTRACT FROM AUTHOR]

The objective of the study was to characterise the expression patterns of the two key components of cortisol action namely HSD11B1 (11‐beta‐hydroxysteroid dehydrogenase type 1) and NR3C1 (nuclear receptor subfamily 3, group C, member 1, also known as the glucocorticoid receptor) in superovulation induced bovine follicles during the periovulation and subsequent corpus luteum (CL) formation. Bovine ovaries containing preovulatory follicles or CL were timely defined during induced ovulation as follows: 0 h before GnRH (Gonadotropin‐releasing hormone) application, and 4, 10, 20, 25 (follicles) and 60 h (early CL) after GnRH. The low mRNA expression of HSD11B1 and NR3C1 in the follicle group before the GnRH application increased significantly in the follicle group 20 h after GnRH and remained high afterward also in the early CL group. In contrast, the high NR3C1 mRNA decreased in follicles 25 h after GnRH (close to ovulation) and significantly increased again after ovulation (early CL). Our results indicated the involvement of HSD11B1 and NR3C1 as the two key components of cortisol action in the local mechanisms coordinating final follicle maturation, ovulation, follicular‐luteal transition and CL development in the cow. [ABSTRACT FROM AUTHOR]

Variations in temperature throughout the reproductive tract have been noted in many species. A recent study found the cervix–rectum temperature differential (CR‐TD) in cattle was related to fertility. The present study aimed to assess the CR‐TD in mares around the time of ovulation and relate it to embryo recover. Over 52 cycles, mares were inseminated with a fertile stallion and embryo recovery was undertaken on Day 7 post ovulation. Further 10 control mares were not inseminated. Rectal and cervical temperatures were measured using a precision thermometer on four or five occasions: the day of deslorelin administration and insemination, the day before ovulation, the day of ovulation (Day 0), the day after ovulation and, for inseminated mares, before embryo recovery on Day 7. One‐way ANOVA showed that the CR‐TD was significantly lower on the day of ovulation in the 36 positive cycles, in which an embryo was recovered, versus the 16 in which the embryo flush was negative (0.21 ± 0.17 vs. 0.40 ± 0.09°C; p < 0.001). Control cycles showed equivalent CR‐TD to positive (0.13 ± 0.22 vs. 0.21 ± 0.17°C; p = 0.196) but not negative cycles (0.13 ± 0.22 vs. 0.40 ± 0.09°C; p < 0.001). A positive embryo recovery was associated with lower CR‐TDs from the time of insemination and deslorelin to the day after ovulation compared to the day of embryo flushing (RM ANOVA; p < 0.001; Pairwise comparisons; p ≤ 0.01, in all cases). Rectal or cervical temperatures per se showed no significant differences between positive, negative or control cycles at any time point. In conclusion, a thermoregulatory process occurs close to ovulation which results in a lower CR‐TD in cycles that produced an embryo versus those which did not. Further characterisation of TDs within the reproductive tract of the mare would increase our understanding of the conditions required for optimum fertility. [ABSTRACT FROM AUTHOR]

Ovulation synchronization protocols are well established and are routinely used in beef livestock systems. In addition to the genetic gain provided using fixed-time artificial insemination (TAI), there is an optimization in production in bovine females that are submitted to this reproduction biotechnique. In Bos indicus cows created in extensive system, a long period of postpartum anestrus is observed due to factors inherent to the presence of the calf and the negative energy balance. Therefore, the main advantage of using hormonal treatments after calving is to anticipate the first ovulation and the return to cyclicity. However, the final response to the TAI protocol based on estrogen (E2) and progesterone (P4) is approximately 80% in suckled Bos indicus beef cows. Hormonal strategies, such as the use of P4 and energy/protein supplementation prior to the TAI protocol, are used to increase the reproductive efficiency of these females. Furthermore, the correct time to start the TAI protocol after calving to optimize productivity and the duration of exposure to P4 during the TAI protocol directly impacts bovine fertility and will be discussed. [ABSTRACT FROM AUTHOR]

Background and Aim: The present study aimed to evaluate and compare the overall and breed‐specific seasonal breeding patterns, fertility rates, cyclicity, and follicular dynamics of Arab, Thoroughbred, and Percheron mares under the subtropical conditions of Pakistan. Materials and Methods: A retrospective analysis of climatic data and breeding records of eleven breeding studs spanning four years (2020–2023) was made to find out the overall seasonality in the breeding pattern of mares. Fifty mares of each breed (n = 150 in total) were scanned by ultrasonography for a calendar year to find the cyclicity pattern and follicular dynamics (follicular growth rate, size of ovulatory follicle, and days from estrus till ovulation). Results and Discussion: The statistical analysis of breeding records demonstrated a clear pattern of seasonal breeding (p< 0.05). The highest monthly foalings were noted in March (247 ± 45.37), and overall breeding activities peaked in Spring season (p< 0.05). Breed‐specific results of Arab, Thoroughbred, and Percheron mares revealed that Arab mares maintained stable breeding activity throughout the year, with the highest activity in spring and peak conception rate in winter (56.25% ± 32.78; p > 0.05). Thoroughbred mares experienced significant seasonal declines from spring to winter with a peak conception rate in winter (63.89% ± 27.37, p > 0.05). Percherons showed the most pronounced seasonal effects, especially with a high fall conception rate (73.04% ± 19.61) and a sharp decrease in winter breeding metrics (p< 0.05). Furthermore, Thoroughbred and Percheron mares displayed the most pronounced seasonal effects on the percentage of cyclic mares 77.3% and 56% in winters (p< 0.05). Moreover, the follicular dynamics of the three breeds also exhibited significant differences (p< 0.05). Conclusion: The current study concludes that seasonal and breed‐specific variability exists among the reproductive parameters of Arab, Thoroughbred, and Percheron mares in subtropics, necessitating breed‐specific reproductive management measures to maximize mare breeding efficiency. [ABSTRACT FROM AUTHOR]

Tailgut cysts are rare lesions which are found in the rectorectal space. They develop in the final section of the intestine from which the rectum and anus extend and vary from being asymptomatic to symptomatic due to pressure on organs or nerves. Tailgut cysts are more common in females, usually between 30 and 60 years of age. They are thought to be benign, with variable malignancy risks. Surgical excision followed by histological examination is the gold standard of treatment, but access and approach to tailgut cysts depend on the location and morphology of the lesion. We present two symptomatic cases of this very rare pathology. In both cases, the cyst and coccyx bone were successfully excised using different approaches. The first patient was a 40-year-old woman with a large cyst which caused morning tenesmus, urinary outflow disorders and painful ovulation. Due to the cyst size, laparotomy was performed, and a combined approach was used. The second patient is a 36-year-old woman with co-existing endometriosis and a cyst causing pain in the sacral spine, constipation and tenesmus. The tumor was excised using a Kraske approach, and due to the infiltration of the coccyx bone it was removed using an osteotome. In this patient, perforation of the cyst was also observed. Both patients completed follow-ups involving regular surgical check-ups and MRI scans. Descriptions of different symptoms and surgical approaches make our study an important source of knowledge for diagnosing and treating these very rare tumors. [ABSTRACT FROM AUTHOR]

Primary ovarian insufficiency (POI) can lead to menstrual disturbance, resulting in ovarian dysfunction before age 40. Prevalence of POI is usually less than 1%; however, ethnicity or population characteristics may affect prevalence. POI is a heterogeneous disease that results from abnormalities in immunological and hormonal factors. Genetic factors can also contribute to POI. Here, we examine FSHR, ESR1, and BMP15 polymorphisms in patients with POI, and controls. We examined a hormonal gene that is important for pregnancy, follicle-stimulating hormone receptor (FSHR), as well as estrogen receptor 1 (ESR1), and associated it with FSHR expression, ovulation rate, and bone morphogenetic protein 15 (BMP15). We examined 139 Korean patients under age 40 with POI, and 350 Korean control participants without POI. Genotyping was performed by a polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) and TaqMan assays. Each identified genotype was subjected to statistical analysis to determine the odds ratios (ORs) and 95% confidence intervals (CIs). In combination genotype analyses, FSHR rs6165 A > G combined with ESR1 rs9340799 A > G, AG/GG (OR: 5.693; 95% CI: 1.088–29.792), as well as FSHR rs6166 A > G combined with ESR1 rs9340799 C > T, AG/GG (OR: 5.940; 95% CI: 1.134–31.131), were significantly associated with POI prevalence. Furthermore, an FSHR rs6165 A > G and BMP rs17003221 C > T, AG/CC combination was associated with POI prevalence (OR: 1.874; 95% CI: (1.059–3.316; p-value: 0.031)). In meta-analysis, FSHR rs6165 AA vs. AG + GG is associated with POI (p = 0.0013), and ESR1 rs2234693 AA vs. AG + GG is also associated with POI (p = 0.0101). Here, we compared the genotypes of FSHR, ESR1, and BMP15 in patients with POI, and controls. We found significant differences in genotype combinations between polymorphisms in FSHR and other genes. Through meta-analysis, we found that ESR1 rs9340799 and rs2234693 are associated with POI prevalence, and that BMP15 rs17003221 increases POI risk. These findings help to improve POI diagnosis in Korean women. [ABSTRACT FROM AUTHOR]

Simple Summary: In Equids, twin pregnancy is an unwanted event, and the traditional management of twin pregnancies involves the early, pre-fixation, manual crushing of one embryo before the 16th day after ovulation when the two embryos are still mobile. However, due to the high percentage of natural reduction of one embryo in unilaterally fixed twins, early post-fixation manual crushing management can also be proposed, allowing the time for natural reduction occurrence. The present study aimed to report data about managing twin pregnancies through natural reduction and post-fixation manual crushing in the Martina Franca donkey breed. The natural reduction of one embryo occurred at 20–21 days after ovulation in 87.5% of unilateral twin pregnancies, with 12.5% of cases requiring post-fixation manual crushing, and none of the bilateral twin pregnancies requiring manual crushing. The single embryo pregnancy rate at 28 days after ovulation was 93.8% for unilateral twin pregnancies and 88.9% for bilateral twin pregnancies, with an overall pregnancy rate of 92%. The live foal rate was 87%. Taken together, the results showed that waiting for the natural reduction of one embryo and using post-fixation manual crushing can be a practical option for the management of twin pregnancy in donkeys. In Equids, undetected twin pregnancy represents the most important cause of abortion and is also associated with high neonatal mortality rates. Therefore, the detection and management of twin pregnancies is pivotal to allow the continuation of single pregnancies. Although pre-fixation manual crushing of one embryo is the most common management of twin pregnancies, and the impact of natural reduction has been reported in mares, very little is known about donkeys. The present study aimed to report results on the natural reduction occurrence and post-fixation manual crushing management of twin pregnancies in the Martina Franca donkey breed. Methods: Twenty-five twin pregnancies were detected at 11–13 days after ovulation. At 16 days after ovulation, twin pregnancies were classified as unilateral or bilateral and left untreated. The occurrence of natural reduction of one embryo was assessed at 20–21 days after ovulation, and post-fixation manual crushing of one embryo was performed in those cases in which natural reduction did not occur. The pregnancy rate at 28 days after ovulation and live foal rate were recorded. Result: Sixteen out of 25 twin pregnancies were unilateral and nine bilateral. At 20–21 days after ovulation, the natural reduction of one embryo occurred in 87.5% of the unilateral and in none of the bilateral twin pregnancies. The remaining twin pregnancies were treated by post-fixation manual crushing of one embryo. The 28-days-after-ovulation single embryo pregnancy rate was 93.8% for unilateral twin pregnancies and 88.9% for bilateral twin pregnancies, with an overall pregnancy rate of 92%. The live foal rate was 87%. Conclusions: The success rate of natural reduction within 20–21 days after ovulation, the 28-days-after-ovulation pregnancy rate, and the live foal rate suggest that waiting for the natural reduction of one embryo and choosing the post-fixation manual crushing of one embryo could be considered as an alternative to traditional early pre-fixation manual crushing in the Martina Franca donkey breed. [ABSTRACT FROM AUTHOR]

STUDY QUESTION Is oocyte developmental competence associated with changes in granulosa cell (GC) metabolism? SUMMARY ANSWER GC metabolism is regulated by the LH surge, altered by obesity and reproductive aging, and, in women, specific metabolic profiles are associated with failed fertilization versus increased blastocyst development. WHAT IS KNOWN ALREADY The cellular environment in which an oocyte matures is critical to its future developmental competence. Metabolism is emerging as a potentially important factor; however, relative energy production profiles between GCs and cumulus cells and their use of differential substrates under normal in vivo ovulatory conditions are not well understood. STUDY DESIGN, SIZE, DURATION This study identified metabolic and substrate utilization profiles within ovarian cells in response to the LH surge, using mouse models and GCs of women undergoing gonadotropin-induced oocyte aspiration followed by IVF/ICSI. PARTICIPANTS/MATERIALS, SETTING, METHODS To comprehensively assess follicular energy metabolism, we used real-time metabolic analysis (Seahorse XFe96) to map energy metabolism dynamics (mitochondrial respiration, glycolysis, and fatty acid oxidation) in mouse GCs and cumulus–oocyte complexes (COCs) across a detailed time course in the lead up to ovulation. In parallel, the metabolic profile of GCs was measured in a cohort of 85 women undergoing IVF/ICSI (n = 21 with normal ovarian function; n = 64 with ovarian infertility) and correlated with clinical parameters and cycle outcomes. MAIN RESULTS AND THE ROLE OF CHANCE Our study reveals dynamic changes in GC energy metabolism in response to ovulatory LH, with mitochondrial respiration and glycolysis differentially affected by obesity versus aging, in both mice and women. High respiration in GCs is associated with failed fertilization (P  <   0.05) in a subset of women, while glycolytic reserve and mitochondrial ATP production are correlated with on-time development at Day 3 (P  <   0.05) and blastocyst formation (P  <   0.01) respectively. These data provide new insights into the cellular mechanisms of infertility, by uncovering significant associations between metabolism within the ovarian follicle and oocyte developmental competence. LIMITATIONS, REASONS FOR CAUTION A larger prospective study is needed before the metabolic markers that were positively and negatively associated with oocyte quality can be used clinically to predict embryo outcomes. WIDER IMPLICATIONS OF THE FINDINGS This study offers new insights into the importance of GC metabolism for subsequent embryonic development and highlights the potential for therapeutic strategies focused on optimizing mitochondrial metabolism to support embryonic development. STUDY FUNDING/COMPETING INTEREST(S) National Health and Medical Research Council (Australia). The authors have no competing interests. TRIAL REGISTRATION NUMBER N/A. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. The objectives of this prospective cohort study were to characterize associations among genomic merit for fertility with ovarian and endocrine function and the estrous behavior of dairy cows during an entire nonhormonally manipulated estrous cycle. Lactating Holstein cows entering their first (n = 82) or second (n = 37) lactation had ear-notch tissue samples collected for genotyping using a commercial genomic test. Based on genomic predicted transmitting ability values for daughter pregnancy rate (gDPR), cows were classified into high (Hi-Fert; gDPR > 0.6, n = 36), medium (Med-Fert; gDPR −1.3 to 0.6, n = 45), and low fertility (Lo-Fert; gDPR < −1.3, n = 38) groups. At 33 to 39 DIM, cohorts of cows were enrolled in the Presynch-Ovsynch protocol for synchronization of ovulation and initiation of a new estrous cycle. Thereafter, the ovarian function and endocrine dynamics were monitored daily until the next ovulation by transrectal ultrasonography and concentrations of progesterone (P4), estradiol, and FSH. Estrous behavior was monitored with an ear-attached automated estrus detection system that recorded physical activity and rumination time. Overall, we observed an association between fertility group and the ovarian and hormonal phenotype of dairy cows during the estrous cycle. Cows in the Hi-Fert group had greater circulating concentrations of P4 than cows in the Lo-Fert group from d 4 to 13 after induction of ovulation and from day −3 to −1 before the onset of luteolysis. The frequency of atypical estrous cycles was 3-fold greater for cows in the Lo-Fert than the Hi-Fert group. We also observed other modest associations between genomic merit for fertility with the follicular dynamics and estrous behavior. We found several associations between milk yield and parity with ovarian, endocrine, and estrous behavior phenotypes as cows with greater milk yield and in the second lactation were more likely to have unfavorable phenotypes. These results demonstrate that differences in reproductive performance between cows of different genomic merit for fertility classified based on gDPR may be partially associated with circulating concentrations of P4, the incidence of atypical phenotypes during the estrous cycles, and, to a lesser extent, the follicular wave dynamics. The observed physiological and endocrine phenotypes might help explain part of the differences in reproductive performance between cows of superior and inferior genomic merit for fertility. [ABSTRACT FROM AUTHOR]

Derived ornithopods, such as hadrosaurids, show a high occurrence of fossilized lesions and diseases. However, paleopathologies in iguanodontians seem to be less common, considering the rich fossil record of these taxa in Europe, in particular in Belgium, Britain and Spain. Here, we describe an iguanodontian femur discovered in England that exhibits a large overgrowth of its lateral aspect, not previously recognized in any other similar remains. The specimen was scanned with micro‐computed tomography (microCT) and later sectioned in three sites of the overgrowth for histological analysis. The femur belongs to an early adult Iguanodontia indet., based on the presence of a woven parallel fibered complex in the outer cortex and three to four lines of arrested growth. Internal analysis of the dome‐like overgrowth suggests it can be diagnosed as a fracture callus. The injury might have negatively impacted upon the animal's locomotion as the trauma had occurred in the region above the knee, a crucial spot for hindlimb musculature. Finally, a cancellous medullary bone‐like tissue was recognized in the medullary cavity next to the pathological overgrowth. An attempt was made to determine the precise nature of this tissue, as medullary bone is linked with the ovulation period in (avian) dinosaurs, whereas other types of endosteal, medullary bone‐like tissue have previously been recognized in pathological bones. [ABSTRACT FROM AUTHOR]