Search Results (116)

This study aimed to evaluate the accuracy of the accelerometer-equipped collar RUMI to detect estrus in dairy cows, establish a recommendation for the optimal timing for artificial insemination (AI) when using this device, and characterize the blood flow of the dominant follicle (F) and the corpus luteum (CL) as ovulation approaches. Forty-seven cycling cows were monitored following synchronization with a modified G6G protocol, allowing for spontaneous ovulation. Ultrasound examinations were conducted every 12 h, starting 48 h after the second PGF2α dose, to monitor uterine and ovarian changes. Blood samples were also collected to determine serum progesterone (P4) levels. Each cow was fitted with a RUMI collar, which continuously monitored behavioral changes to identify the onset, offset, and peak of activity of estrus. One-way ANOVA assessed the relationship between physiological parameters and time before ovulation. Results showed that the RUMI collar demonstrated high specificity (100%), sensitivity (90.90%), and accuracy (93.62%) for estrus detection. The optimal AI window was identified as between 11.4 and 15.5 h after heat onset. Increased blood flow to the F and reduced luteal activity were observed in the 48 h prior to ovulation. Further research is needed to assess the influence of this AI window on conception rates, and if it should be modified considering external factors. Full article

Due to the growing environmental burden of endocrine-disrupting chemicals (EDCs), there is an increasing concern regarding the reproductive hazards posed by synthetic estrogens, particularly diethylstilbestrol (DES). However, the precise mechanisms by which DES disrupts uterine endocrine function and immune homeostasis leading to pregnancy failure remain unclear. Given that wild rodents serve as key reservoirs for zoonotic diseases such as plague, reproductive interventions targeting their pregnancy processes hold significant ecological implications for disease control. In this study, female mice in estrus were randomly divided into four experimental groups, receiving DES at doses of 0 (control), 0.02 (low), 0.2 (medium), and 2 mg/kg (high), respectively. For five consecutive days, mice were injected subcutaneously on a daily basis, with the goal of examining DES-related alterations in hormone secretion and local immune responses within the uterus and spleen. It was found that high-dose DES treatment significantly increased maternal body weight and spleen weight during early pregnancy (p < 0.05). Meanwhile, reproductive function declined progressively with increasing doses, as indicated by decreased ovarian and uterine weights, fewer embryos, and extended estrous cycle duration (p < 0.05). Hematoxylin and eosin staining revealed that high-dose DES markedly reduced uterine gland density at day P5, accompanied by epithelial vacuolar degeneration and nuclear pyknosis. The proportion of uterine glands relative to total uterine area also decreased significantly with increasing DES doses. Moreover, DES inhibited lymphocyte proliferation in both the uterus and spleen in a dose-dependent fashion, with ConA- and LPS-induced proliferation rates decreasing by 0.78–30.70% and 1.91–18.20%, respectively (p < 0.05). The proinflammatory cytokine IL-2 was significantly elevated by DES, whereas the anti-inflammatory cytokine IL-4 showed a notable decrease (p < 0.05). DES administration notably decreased uterine expression of proliferating cell nuclear antigen. In contrast, the numbers of B-cell lymphoma 2- and Bcl-2-associated X protein-positive cells rose, along with upregulated levels of inducible nitric oxide synthase. Furthermore, DES impaired antioxidant defenses in both the uterus and spleen, evidenced by the decreased activities of superoxide dismutase and glutathione peroxidase, reduced total antioxidant capacity, and elevated malondialdehyde levels. This study elucidates the multifaceted mechanisms by which DES impairs the early gestational reproductive environment, filling a critical knowledge gap regarding its interference with the uterus–immune axis, and expands the current understanding of the ecotoxicological impacts of endocrine-disrupting chemicals. Full article

Modern beef cattle reproductive management faces increasing challenges due to the growing global demand for beef. Reproductive efficiency is a critical factor determining the productivity and profitability of beef cattle operations. Optimal reproductive performance in a beef cattle herd is achieved when each cow produces one calf per year, maintaining a calving interval of 365 days. However, this goal is difficult to achieve, as the gestation period in beef cows lasts approximately 280 days, leaving only 80–85 days for successful conception. Traditional methods, such as visual estrus detection, are becoming increasingly unreliable due to expanding herd sizes and the subjectivity of visual observation. Additionally, silent estrus—where ovulation occurs without noticeable behavioral changes—further complicates the accurate estrous-based identification of the optimal insemination period. To enhance reproductive efficiency, advanced technologies are increasingly being integrated into cattle management. Sensor-based monitoring systems, including accelerometers, pedometers, and ruminoreticular boluses, enable the precise tracking of activity changes associated with the estrous cycle. Furthermore, infrared thermography offers a non-invasive method for detecting body temperature fluctuations, allowing for more accurate estrus identification and optimized timing of insemination. The use of these innovative technologies has the potential to significantly improve reproductive efficiency in beef cattle herds and contribute to overall farm productivity and sustainability. The objective of this review is to examine advancements in smart technologies applied to beef cattle reproductive management, presenting commercially available technologies and recent scientific studies on innovative systems. The focus is on sensor-based monitoring systems and infrared thermography for optimizing reproduction. Additionally, the challenges associated with these technologies and their potential to enhance reproductive efficiency and sustainability in the beef cattle industry are discussed. Despite the benefits of advanced technologies, their implementation in cattle farms is hindered by financial and technical challenges. High initial investment costs and the complexity of data analysis may limit their adoption, particularly in small and medium-sized farms. However, the continuous development of these technologies and their adaptation to farmers’ needs may significantly contribute to more efficient and sustainable reproductive management in beef cattle production. Full article

Heat stress (HS) is a major environmental factor negatively impacting the reproductive performance of livestock. This study investigates the molecular mechanisms of heat stress on the hypothalamic–pituitary–ovarian (HPO) axis in Hu sheep. A heat-stressed animal model was established, and high-throughput RNA sequencing (RNA-seq) was employed to analyze gene expression in the hypothalamus, pituitary, and ovarian tissues of both control and heat-stressed groups. The results revealed significant changes in estrus behavior, hormone secretion, and reproductive health in heat-stressed sheep, with a shortened estrus duration, prolonged estrous cycles, and decreased levels of FSH, LH, E₂, and P4. A total of 520, 649, and 482 differentially expressed genes (DEGs) were identified in the hypothalamus, pituitary, and ovary, respectively. The DEGs were enriched in pathways related to hormone secretion, neurotransmission, cell proliferation, and immune response, with significant involvement of the p53 and cAMP signaling pathways. Tissue-specific responses to heat stress were observed, with distinct regulatory roles in each organ, including GPCR activity and cytokine signaling in the hypothalamus, calcium-regulated exocytosis in the pituitary, and cilium assembly and ATP binding in the ovary. Key genes such as SYN3, RPH3A, and IGFBP2 were identified as central to the coordinated regulation of the HPO axis. These findings provide new insights into the molecular basis of heat stress-induced impairments in reproductive function—manifested by altered estrous behavior, reduced hormone secretion (FSH, LH, E₂, and P4), and disrupted gene expression in the hypothalamic–pituitary–ovarian (HPO) axis—and offer potential targets for improving heat tolerance and reproductive regulation in sheep. Full article

Infertility is a complex and common problem in reproductive medicine consultations. Three factors must be examined during the preconception phase: breeding management, the fertility of the bitch, and the fertility of the stud dog. Among these factors, improper breeding management remains the main cause of reproductive failure, with accurate recognition of ovulation being crucial for successful mating. Artificial insemination allows for a thorough evaluation of semen quality compared to natural mating. In addition, genetic selection, nutritional factors, and reproductive health management can either impair or improve the fertility of females and males. Idiopathic infertility can occur in bitches, but it is important to rule out other possible causes first. In bitches with irregular estrus cycles, ovarian dysfunction and endocrine imbalances should be investigated. In bitches with regular cycles, uterine disorders such as cystic endometrial hyperplasia, endometritis or congenital anomalies may be the cause. Both mating-related and chronic endometritis are recognized as contributing factors to infertility. Infectious agents, particularly Brucella spp. and Mycoplasma spp., should also be evaluated, although interpretation of Mycoplasma test results requires caution. In males presenting with poor semen quality, potential causes include infectious diseases (with brucellosis always requiring exclusion), hormonal imbalances, and the impact of exogenous treatments. The article underscores the critical role of comprehensive diagnostic protocols, proactive health surveillance, and data-driven breeding strategies in systematically addressing this multifaceted challenge. Full article

The combined effects of human chorionic gonadotropin (hCG) treatment on Day 5 (Day 0 = the day of artificial insemination: AI) and intravaginal progesterone device (IVPD) treatment from Day 5 to 19 on the conception rate and plasma sex steroid hormone were examined in lactating dairy cows. In Experiment 1, cows were divided into a non-treatment group (n = 181), untreated; an IVPD group (n = 74), with an IVPD inserted into the vagina from Day 5 to 19; and an hCG + IVPD group (n = 87), with 3000 IU hCG administered intramuscularly on Day 5 and an IVPD inserted into the vagina from Day 5 to 19. The conception rates of the hCG + IVPD group, which underwent ≤3 AIs (52.8%) and >3 AIs (73.3%), and the IVPD group, which underwent >3 AIs (63.0%), were significantly higher than that of the non-treatment group, which underwent ≤3 AIs (34.2%). In Experiment 2, blood samples were collected from the non-treatment group (n = 6), the IVPD group (n = 6), and the hCG + IVPD group (n = 7) on days 5, 8, 12, and 15 from estrus to measure plasma progesterone (P₄) and total estrogen (E) concentrations. The plasma P₄ concentration of the hCG + IVPD group tended to be higher than that of the non-treatment group on Day 15; however, plasma E concentrations were not different among groups. These results suggest that the conception rate was improved by hCG + IVPD treatment regardless of AI number because of higher plasma P₄ concentrations later in the estrous cycle. Full article

The issue of stray cats and dogs is a global concern with considerable implications for animal welfare and public health. This review aims to provide an updated and comprehensive analysis of non-surgical contraceptive methods tested in studies controlled in vivo in feline and canine females. Immunocontraception via vaccination against gonadotropin-releasing hormone (GnRH), the luteinizing hormone receptor, zona pellucida proteins, and sperm, or use of viral-vectored delivery, is yet developing. Hormonal treatment (progestins, androgens, or GnRH) analogs act directly to block the reproductive axis. However, it produced essential side effects. Analogs of kisspeptin, non-steroid anti-inflammatory drugs such as firocoxib, and delivery of cytotoxins to the pituitary have shown non-conclusive results. Additional methods have also been tested, such as intraovarian injection of necrosing compounds or intravaginal and intrauterine devices. At present, neither of these methods offers permanent sterility that can replace surgical sterilization techniques. To our knowledge, none are currently authorized by the Food and Drug Administration (FDA) or the European Medicines Agency (EMA) for contraceptive methods or sterilization of cats or dogs. Therefore, it is necessary to continue the development of a compound that warrants the sterility of cats and dogs. Full article

This study examines the reproductive outcomes of Lacaune-crossbred ewes and hoggets in intensive production systems, focusing on vaginal prolapse and hydrometra associated with flaws in estrus synchronization (E.S.) protocols. Data from multiple farms were combined for analysis due to the absence of significant variation at the farm level. The findings revealed a strong association between vaginal prolapse, parity, and litter size, with hoggets carrying multiple fetuses facing the highest risk (p < 0.0001). This highlights the need to reconsider equine chorionic gonadotropin (eCG) administration in hoggets, as it increases the likelihood of multiple pregnancies and, consequently, prolapse. Additionally, a progressive rise in hydrometra prevalence was observed with repeated synchronization cycles in ewes, increasing from 0.51% after the third treatment to 12.33% after the fourth (p < 0.0001). Notably, in this study, the four synchronization cycles were applied over a relatively short period (7.22 ± 1.64 months), further supporting concerns that excessive hormonal treatments within a compressed timeframe exacerbate reproductive dysfunction. The results corroborate previous reports that prolonged progesterone exposure can impair uterine function, leading to fluid retention and hydrometra. To mitigate these risks, estrus synchronization protocols should be critically reassessed—especially by extending the interval between successive treatments—to protect reproductive health and animal welfare. These findings not only underscore the need for more welfare-conscious practices in intensive sheep farming but also encourage further research aimed at refining hormonal management strategies in dairy ewe reproduction. Full article

Background: Premenstrual syndrome is characterized by emotional changes, including anxiety and depression symptoms, which may be treated with anxiolytic and antidepressant drugs, as well as estrogen therapy. However, steroidal estrogen therapy is contraindicated for patients with a potential risk of developing estrogen-dependent cancers through interactions with estrogen receptor α (ERα). Alternatively, genistein produces estrogenic effects in animals and humans at dietary dosages that act on the nuclear and membrane ERα, estrogen receptor β (ERβ), and the G-protein-coupled estrogen receptor (GPER). These receptors are likely involved in the anxiety symptoms observed in premenstrual disorders. The objective of this study was to evaluate the effects of genistein and 17β-estradiol on anxiety-like behavior and the plasma concentrations of estradiol and progesterone throughout the ovarian cycle of Wistar rats. Methods: The effect of the administration of 0.09 mg/kg of genistein or 17β-estradiol was evaluated using the elevated plus maze (EPM) test, locomotor activity test (LAT), and light/dark box (LDB) test, as well as by assessing the plasma concentrations of estradiol and progesterone, while considering the ovarian cycle phases. Results: Higher levels of anxiety-like behavior were detected in the metestrus–diestrus phase compared to the proestrus–estrus phase, which was associated with low concentrations of estradiol. Genistein, similarly to 17β-estradiol, significantly reduced anxiety-like behaviors in the EPM and LDB; however, 17β-estradiol, but not genistein, significantly increased the plasma estradiol concentration. No significant changes were found in locomotor activity or the plasma progesterone concentrations due to the treatments. Conclusions: These findings suggest that genistein may be useful in the development of alternative therapies to reduce the anxiety associated with low steroid hormone concentrations, which occur in premenstrual syndrome. Genistein could be an alternative to steroidal estrogen therapy to avoid potential side effects due to estradiol or antidepressant treatments, although it still requires medical care. Full article

An experiment was designed to evaluate modifications to the 7 & 7 Synch protocol, with the hypothesis that tandem administration of prostaglandin F2α (PG) and gonadotropin-releasing hormone (GnRH) during the presynchronization portion of the protocol would generate a convergent ovarian response among anestrous and estrous cycling females. Nulliparous, primiparous, and multiparous Angus and Angus-cross females were blocked based on parity and pre-treatment luteal status and, within a block, randomly assigned to one of three treatments. The females assigned to the 7 & 7 Synch treatment (n = 765) received an intravaginal progesterone-releasing insert (CIDR^®) and an administration of PG on Day 0, GnRH on Day 7, and PG concurrent with CIDR removal on Day 14. Estrotect™ estrus detection aids were applied on Day 14 at the time of CIDR removal and PG administration. The females assigned to the 7 & 7 + G treatment (n = 769) received the same treatment schedule, with the modification that GnRH was administered in tandem with PG on Day 0. The females assigned to the 7 & 7 + G + P treatment (n = 786) received the same treatment schedule, with the modification that GnRH was administered in tandem with PG on both Days 0 and 7. Fixed-time artificial insemination (FTAI) was performed at 54 ± 2 h (nulliparous) or 66 ± 2 h (primiparous and multiparous) after CIDR removal. Transrectal ovarian ultrasonography was performed on Days 7 and 14 to characterize the largest follicle diameter (LFD) and the presence of corpora lutea (CL). Estrus prior to FTAI was characterized using estrus detection aids. Pregnancy status was determined via transrectal ultrasonography approximately 60–100 days after FTAI. The proportion of multiparous females with CL on Day 14 tended to be greater following treatment with 7 & 7 Synch or 7 & 7 + G (90% and 87%, respectively), as compared to females treated with 7 & 7 + G + P (82%; p = 0.09). A greater proportion of multiparous females expressed behavioral estrus prior to FTAI when treated with 7 & 7 + G + P (90%) as compared to multiparous females treated with 7 & 7 + G (79%; p < 0.002) or 7 & 7 Synch (78%; p = 0.0004); however, pregnancy rates resulting from FTAI did not differ based on treatment. In summary, tandem administration of GnRH and PG on Days 0 and 7 of the 7 & 7 Synch protocol effectively generated a convergent ovarian response among females with variable pretreatment luteal status but failed to enhance pregnancy rates to FTAI. Full article

Against the backdrop of precision livestock farming, sow behavior analysis holds significant theoretical and practical value. Traditional production methods face challenges such as low production efficiency, high labor intensity, and increased disease prevention risks. With the rapid advancement of optoelectronic technology and deep learning, more technologies are being integrated into smart agriculture. Intelligent large-scale pig farming has become an effective means to improve sow quality and productivity, with behavior recognition technology playing a crucial role in intelligent pig farming. Specifically, monitoring sow behavior enables an effective assessment of health conditions and welfare levels, ensuring efficient and healthy sow production. This study constructs a 3D-CNN model based on video data from the sow estrus cycle, achieving analysis of SOB, SOC, SOS, and SOW behaviors. In typical behavior classification, the model attains accuracy, recall, and F1-score values of (1.00, 0.90, 0.95; 0.96, 0.98, 0.97; 1.00, 0.96, 0.98; 0.86, 1.00, 0.93), respectively. Additionally, under conditions of multi-pig interference and non-specifically labeled data, the accuracy, recall, and F1-scores for the semantic recognition of SOB, SOC, SOS, and SOW behaviors based on the 3D-CNN model are (1.00, 0.90, 0.95; 0.89, 0.89, 0.89; 0.91, 1.00, 0.95; 1.00, 1.00, 1.00), respectively. These findings provide key technical support for establishing the classification and semantic recognition of typical sow behaviors during the estrus cycle, while also offering a practical solution for rapid video-based behavior detection and welfare monitoring in precision livestock farming. Full article

Identifying the specific factors secreted during early pregnancy is an effective method for pregnancy detection in cattle, helping to reduce empty pregnancies in the industry. To systematically investigate metabolic variations between early pregnancy and the estrous cycle and their relationship with pregnancy progression, this study utilized four-dimensional data-independent acquisition (4D-DIA) proteomics and liquid chromatography–tandem mass spectrometry (LC-MS/MS) metabolomics to analyze serum samples collected from Chinese native yellow cattle at day 0 and day 21 post-mating, combining bioinformatics analysis with experimental validation. The platelet activation signaling pathway and angiogenesis-related proteins were significantly upregulated. Among them, fibrinogen alpha/beta/gamma chains (FG) exhibited notable differences, with their branched-chain protein FGB showing highly significant upregulation (p = 0.003, Log₂FC = 2.167) and tending to increase gradually during early pregnancy, suggesting that FGB could be one of the important indicators of early pregnancy in Chinese native yellow cattle. Among the differential metabolites, 11-Deoxy prostaglandin F1α (p < 0.001, Log₂FC = 1.563), Thromboxane B1 (p = 0.002, Log₂FC = 3.335), and Homo-Gamma-Linolenic Acid (C20:3) (p = 0.018, Log₂FC = 1.781) were also increased, indicating their involvement in the regulation of the platelet activation signaling pathway. The platelet activation signaling pathway plays a crucial role in maternal immune tolerance and placental vascularization, which are essential for embryo implantation and placental development. These findings indicate that FGB has the potential to be a valuable biomarker for early cattle pregnancy detection, thereby improving pregnancy diagnosis accuracy, reducing economic losses caused by undetected empty pregnancies and enhancing reproductive efficiency in the cattle industry. Undoubtedly, our research outcomes must be validated with future studies, and a larger sample size as well as the evaluation of the potential endocrine effects induced by the synchronized estrus treatment must be considered. Full article

A 2-year-old Large White research gilt was presented to the Comparative Theriogenology service at WSU for infertility. She was produced from the transfer of genetically modified embryos obtained via in vitro fertilization (IVF) that had been treated with CRISPR-Cas9 reagents to mutate the NANOS2 gene. Since birth, the gilt showed a so-called “skyhook” vulva and abnormal estrous cycles. She was artificially inseminated multiple times, starting at 5 months of age, with semen from a proven fertile boar, but never conceived. On transabdominal ultrasonography of the reproductive tract, a unilateral ovotestis was suspected. An exploratory laparotomy was performed and confirmed the presence of ovarian and testicular tissue on her right gonad. The diagnosis was confirmed by histology following unilateral gonadectomy. The cytogenic evaluation revealed the gilt to be XX 38, SRY-negative. The gilt showed estrus signs 4 months after surgery, and artificial insemination was performed, which resulted in pregnancy. She delivered six piglets. Necropsy was performed following humane euthanasia. Several abnormalities of the reproductive tract were discovered, including a unilateral mucometra due to a complete septum, preventing communication between the right uterine horn and the body of the uterus. This case is novel because it demonstrates that surgical removal is an effective treatment for fertility in SRY-negative XX DSD gilts with partial masculinization, posing the presence of a normal ovary and a developed oviduct and uterine horn. Full article

This study aimed to investigate the effects of oxidative stress and antioxidant activity in plasma and uterine fluid during early postpartum on the reproductive performance of Japanese Black cows. A total of 17 Japanese Black cows were included in this study. Plasma and uterine fluid samples were collected at days 7 and 14 of the estrus cycle (n = 17), between 47–67 days postpartum, and diacron-reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP) were measured. d-ROMs, BAP, and oxidation stress index (OSI: d-ROMs/BAP × 100) were compared between pregnant and nonpregnant cows at first postpartum artificial insemination (AI), cows pregnant less than 120 days postpartum (<120 days postpartum), and cows pregnant more than 120 days postpartum (≥120 days postpartum) regardless of AI number. The uterine fluid OSI on day 7 of the estrus cycle was significantly higher in cows pregnant ≥ 120 days postpartum (p < 0.05). d-ROMs, BAP, and OSI of uterine fluid during early postpartum were useful indicators for determining the subsequent reproductive performance of Japanese Black cows. Full article

This study evaluated the effects of serum (egpS) and follicular fluid (egpFF) from estrus guinea pigs as in vitro maturation (IVM) supplements for natural cycle guinea pig oocytes. Two experiments were conducted: the first assessed three IVM media, a commercial medium (CMOM) and two homemade media (HMOM-P and HMOM-S), for oocyte in vitro maturation using 615 bovine oocytes, while the second evaluated the incorporation of 5%, 10%, and 20% egpFF or egpS into IVM media for 1744 guinea pig oocytes. Initially, we optimized the IVM base medium using bovine oocytes to determine the most suitable culture conditions. The results obtained from these experiments served as a critical foundation for subsequent supplementation trials conducted with guinea pig oocytes. The oocytes were cultured in 70 μL drops under controlled atmospheric conditions, and maturation rates were assessed based on cumulus cell expansion and nuclear progression. The HMOM-S medium significantly enhanced cumulus cell expansion (72.5 ± 2.88%) compared with the CMOM medium (57.7 ± 5.33%; p < 0.05). Supplementation with egpFF at 5% (68.8 ± 6.22%), 10% (76.3 ± 5.39%), and 20% (80.9 ± 6.22%) significantly improved both cumulus cell expansion and nuclear progression in high-quality oocytes (types A and B), compared to the control group (43.3 ± 4.82%). Conversely, supplementation with egpS did not have a significant effect on cumulus cell expansion (p > 0.05); however, it notably improved nuclear maturation in low-quality oocytes (type C) at concentrations of 10% and 20% (p < 0.05). This resulted in an overall improvement in maturation outcomes, particularly for oocytes with compromised initial quality. These findings demonstrated that the IVM of guinea pig oocytes using HMOM-S medium was significantly enhanced by the presence of egpFF, whereas egpS supplementation exhibited a less pronounced effect on IVM outcomes. Full article