Search Results (748)

Milk production in dairy herds is determined by both intrinsic and extrinsic factors, with reproductive efficiency serving as a primary determinant. Infectious, nutritional, and management-related challenges can reduce this efficiency. Following parturition, cows are more susceptible to clinical disorders due to a temporary loss of integrity in the cervix, vagina, and vulva, which allows environmental bacteria to ascend and alter the vaginal microbiota. These microbial changes may disrupt endocrine responses related to conception and contribute to repeat breeder cow syndrome (RBCS), which is defined as failure to conceive after three or more inseminations. This study investigated associations among cultivable vaginal bacteria, circulating progesterone and glucose concentrations, and reproductive performance in 30 fourth-parity Holstein cows with a body condition score of 3.5. Cows were classified by reproductive history as repeat breeders (RBCS; n = 14) or controls (CTL; n = 16). Vaginal mucosal samples were collected at insemination and cultured on blood agar and MacConkey media under aerobic and microaerobic conditions. Bacterial identification was conducted using Gram staining and standard biochemical assays. Blood samples were collected at insemination, on day 5 post-insemination, and every two days thereafter to measure progesterone and glucose concentrations. Fertility outcomes were analyzed using PROC GLIMMIX, and hormonal data were analyzed using mixed models with repeated measures. The bacterial genera identified included Bacillus, Escherichia coli, Staphylococcus, Klebsiella, Proteus, Streptococcus, and Actinomyces. Progesterone and glucose concentrations did not differ significantly between groups (p > 0.05). However, the fertility rate (p < 0.05; CTL:87.50% vs. RBCS:57.14%) and number of attempts to conceive (p < 0.001; CTL:2.5 vs. RBCS:6.7) differed statistically between treatments. A higher prevalence of S. hyicus was detected in RBCS cows, and E. coli, S. hyicus, and Proteus spp. were more frequently detected in non-pregnant cows. These findings suggest that the identified cultivable vaginal bacteria are associated with reproductive status in dairy cows. Full article

The conventional window for ultrasonic pregnancy diagnosis in sows is 22–25 days post-insemination, which often results in missed opportunities for the optimal re-insemination of non-pregnant sows and elevated production costs. This present study aimed to establish an early pregnancy detection method for sows at 12–18 days post-insemination, thereby providing a reference for efficient reproductive management. Saliva, urine and vaginal secretions were collected from sows during this period, and seven metabolites were quantified. Seven machine learning models were employed for data analysis, after which the optimal combination was determined, and the detection protocol was refined using recursive feature elimination. The results revealed that the majority of metabolites in saliva and urine differed significantly between pregnant and non-pregnant groups (p < 0.05). Among the models evaluated, the random forest algorithm exhibited the best predictive performance, with accuracy ranging from 0.59 to 1.00. Saliva sampled at 17 days post-insemination was identified as the optimal diagnostic medium, and 100% prediction accuracy was achieved by measuring only three metabolites: Glc, Ste, and Xan. The diagnostic approach established in this study allows pregnancy detection 5–8 days earlier than conventional methods, with the additional benefits of non-invasive sampling and minimal stress to sows. Accordingly, it provides a novel reference for enhancing the efficiency of swine production. Full article

Testicular tumors are the most common neoplasms of the canine male reproductive tract, corresponding to approximately 25% of all tumors in intact males. A large percentage of cases are characterized by one of three main tumor types: seminomas, interstitial Leydig cell tumors, or Sertoli cell tumors. Clinical importance is primarily associated with endocrine activity rather than malignant behavior; orchiectomy is the treatment of choice for most canine testicular cancers. Endocrine activity, particularly estrogen secretion, may result in feminization syndrome and, in severe cases, bone marrow suppression. The diagnostic approach combines physical examination, ultrasonography with hormonal assessment using endocrine testing (testosterone, estradiol, and T:E ratio), and/or tissue level evidence of the estrogen effect (preputial cytology). Management is centered on orchiectomy; unilateral surgery may be considered when the contralateral testis is clinically and ultrasonographically normal and when preservation of reproductive capacity or working ability is still a priority. Dogs with hormonally active tumors benefit from postoperative hematologic and endocrine monitoring. Recent advances in immunohistochemistry (IHC), such as Ki-67 and inhibin-α markers, and imaging techniques are improving tumor characterization and individualized clinical decision making. Full article

Bovine ocular squamous cell carcinoma (BOSCC) is the most common ocular tumour in cattle, with a multifactorial aetiology involving ultraviolet (UV) radiation, genetic factors, pigmentation, and management practices. A detailed epidemiological characterisation of BOSCC in the Azores, Portugal, is provided, with particular emphasis on its spatial distribution and potential risk determinants. Data were obtained through an epidemiological questionnaire completed by field veterinarians between August 2023 and March 2025. A total of 85 BOSCC cases were recorded across 62 farms—45 on Terceira Island and 17 on São Miguel Island. All affected animals were adult Holstein Friesian dairy cows, managed under extensive pasture-based systems. The nictitating membrane was the most frequently affected structure (69.5%), and multiple lesions occurred in 20% of the cases. Farms located at 200–400 m of altitude presented the highest number of cases. Continuous exposure to UV under pasture-based management represents the main environmental risk factor. Although periocular pigmentation may provide partial protection, other environmental and genetic factors can also contribute to tumour development. Artificial insemination is considered a promising preventive tool, enabling genetic selection for protective traits such as periocular pigmentation. This research provides the first regional epidemiological characterization of BOSCC in the Azores, highlighting the interplay among environmental, genetic, and management-related factors in disease occurrence. Full article

Background and Objectives: Endometrial polyps are common in women presenting with subfertility, yet uncertainty persists regarding which lesions warrant removal and how best to integrate hysteroscopic management with contemporary fertility treatment pathways. This narrative review synthesizes current evidence on pathophysiological mechanisms, diagnostic approaches, fertility outcomes, and practical clinical management for women under 40 years of age. Materials and Methods: PubMed/MEDLINE, Embase, Scopus, Web of Science, and the Cochrane Library were searched for English-language human studies published between January 2005 and December 2025. From 2352 records identified, 83 studies were included after screening of 1517 unique records (7 randomized controlled trials, 12 systematic reviews/meta-analyses, 14 prospective cohort studies, 31 retrospective cohort studies, 5 case–control and other study designs, 11 narrative reviews and supporting evidence studies, 1 clinical guideline, and 2 targeted 2025 additions). This structured narrative review employed a systematic search strategy to ensure comprehensive coverage, with evidence synthesized thematically in accordance with the SANRA guidelines. No formal risk-of-bias assessment or pre-registered protocol was used. Results: Across treatment modalities, hysteroscopic polypectomy was consistently associated with improved fertility outcomes. The landmark Pérez-Medina randomized trial reported a relative risk of 2.1 (95% CI 1.5–2.9) for pregnancy after polypectomy before intrauterine insemination. For IVF/ICSI, reported clinical pregnancy rates after polypectomy range from 53–72% and live birth rates from 43–66%. Proposed mechanisms include mechanical interference, chronic inflammation with cytokine dysregulation, altered endometrial receptivity (including dysregulation of HOXA10/HOXA11), and impaired decidualization. Conclusions: Current evidence supports hysteroscopic polypectomy as an effective intervention to improve fertility outcomes in subfertile women with endometrial polyps, particularly prior to intrauterine insemination. For IVF/ICSI, polypectomy of documented polyps appears beneficial, though evidence quality is moderate and heterogeneity exists across studies. It is critical to distinguish routine screening hysteroscopy before IVF from targeted polypectomy when a polyp has been documented. Contemporary guidance (including the 2024 SOGC guideline) favors polypectomy for symptomatic polyps and those that meet specific clinical criteria; for small asymptomatic polyps (<10 mm), individualized decision-making is appropriate, given limited direct evidence and the potential for spontaneous regression. Future research should clarify molecular predictors of polyp-associated infertility, optimal timing relative to fertility treatment, and long-term reproductive outcomes. Full article

This study aimed to evaluate the impact of coenzyme Q10 (CoQ10) supplementation during in vitro maturation (IVM) and/or vitrification of immature dromedary camel oocytes on their subsequent in vitro developmental competence. Additionally, total antioxidant capacity (TAC) and malondialdehyde (MDA) concentrations were assessed in the IVM spent medium. In experiment 1, cumulus–oocyte complexes (COCs, n = 808) collected from slaughtered dromedary camel ovaries were cultured in IVM media supplemented with either 0, 25, 50, or 100 μM CoQ10 for 36 h. Matured oocytes were then fertilized in vitro with epididymal camel spermatozoa. Eighteen hours post-insemination (pi), presumptive zygotes were cultured in vitro for 7 days. In experiment 2, a total of 875 COCs were randomly allocated to one of four experimental groups, namely (a) Vit−/IVM− (control) group, where COCs were vitrified in vitrification solution (VS; 25% DMSO + 25% EG) and matured in IVM media without CoQ10 supplementation; (b) Vit+/IVM− group, in which COCs were vitrified in a VS supplemented with 50 µM CoQ10 and matured in IVM media without CoQ10 supplementation; (c) Vit−/IVM+ group, where COCs were vitrified in VS without CoQ10 supplementation and matured in IVM media supplemented with 50 µM CoQ10; and (d) Vit+/IVM+ group, where COCs were vitrified in VS and matured in IVM media, both supplemented with 50 µM CoQ10. Following vitrification and warming, oocyte viability was evaluated morphologically and by trypan blue staining. Viable oocytes were then matured, fertilized, and cultured in vitro. In experiment 3, TAC and MDA concentrations in the IVM spent media were analyzed. Results showed that 50 µM CoQ10 supplementation to IVM media enhanced cumulus expansion, nuclear maturation, cleavage, and blastocyst rates (experiment 1). Adding 50 µM CoQ10 to the VS enhanced (p ≤ 0.05) oocyte viability compared to those vitrified in CoQ10-free media. Cumulus cell expansion and nuclear maturation rates were higher (p ≤ 0.05) in Vit−/IVM+ than in Vit+/IVM+ and Vit−/IVM− groups. Furthermore, cleavage and blastocyst rates were the highest (p ≤ 0.05) in Vit−/IVM+ group (experiment 2). The concentrations of TCA were higher, and the concentrations of MDA were lower (p ≤ 0.05) in Vit−/IVM+ than in other groups (experiment 3). In conclusion, supplementation of CoQ10 in the maturation medium of vitrified–warmed immature dromedary camel oocytes may enhance their in vitro developmental competence. Full article

The recovery and cryopreservation of epididymal spermatozoa enable genetic preservation in male dogs that die unexpectedly or require castration; however, sperm collection is typically performed immediately after surgery, and artificial insemination is often surgical. This study aimed to evaluate whether epididymides stored at 4–5 °C for 24 h prior to sperm recovery retain fertilizing capacity after cryopreservation and whether pregnancy can be achieved using endoscopically guided transcervical intrauterine insemination. Testes and epididymides from an eight-month-old German Shepherd dog were stored in physiological saline at 4–5 °C for 24 h following castration. Spermatozoa were recovered from the cauda epididymis using single-incision aspiration, evaluated, frozen according to the Uppsala method, and stored in liquid nitrogen for two months. After thawing, 62 × 10⁶ progressive motile spermatozoa were inseminated once into a bitch in heat using transcervical endoscopic guidance. Pregnancy was confirmed by ultrasonography, and nine healthy puppies were delivered at term. These findings demonstrate that 24 h refrigerated storage of the epididymis does not impair post-thaw fertilizing ability and that non-surgical transcervical intrauterine insemination represents an effective alternative to surgical techniques for the use of frozen–thawed epididymal semen in dogs. Full article

The effects of reproductive technologies, namely, artificial insemination (AI) and multiple ovulation embryo transfer (MOET), on the production, health, and longevity of Holstein–Friesian cows were evaluated. Data were obtained from the time period between 2017 and 2024 on a Hungarian dairy farm and consisted of 1783 cows (1544 AI and 239 MOET). Deep-frozen semen from identical bulls was used for both the AI and MOET groups. Disease incidence, productive life, and early-lactation milk production phenotypes were collected in these cows. MOET cows demonstrated significantly higher milk yield during the first 100 days of lactation but had a 43.9% greater risk of culling compared with AI cows (p < 0.05). Metabolic and reproductive disorders were the most common reasons for culling cows, with increased frequency of health issues correlating with higher culling risk ratios (p < 0.05). While MOET cows showed lower incidences of metabolic disorders, reproductive problems, and mastitis, their shorter productive lifespan likely limited overall disease exposure. Nevertheless, when MOET cows experienced illness, the impact was more severe, particularly in relation to metabolic issues (p < 0.05). These findings highlight trade-offs between improved genetic potential and health resilience in MOET-derived cows. Despite their higher productivity, their management may require greater health vigilance. This study offers practical insights for dairy producers in selecting reproductive strategies to balance genetic gain, herd health, and longevity under intensive production systems. Full article

Nano-graphene oxide (NGO) is a nanomaterial that has been frequently used in the fields of health and bioengineering in recent years. However, its potential use in semen cryopreservation is still in the exploratory phase. In this study, Angora bucks, a breed with low resistance to cold shock, were used. Sperm was collected from five different Angora bucks, pooled, diluted with a Tris-based egg yolk diluent, and frozen with the addition of NGO at two different sizes (50 and 500 nm) and doses (10 and 50 µg/mL). Nanoparticle characterization was performed using field emission scanning electron microscopy (FE-SEM), dynamic light scattering (DLS), and Fourier-transform infrared spectroscopy (FTIR). Post-thaw sperm analyses were evaluated based on motility and kinematic parameters, mitochondrial membrane potential (MMP), plasma membrane and acrosome integrity (PMAI), and DNA fragmentation. Applying 50 nm NGO at a dose of 50 µg/mL led to statistically significant improvements in motility and PMAI (p < 0.05). The same dose of 500 nm NGO, however, only showed a statistically significant improvement in the PMAI parameter (p < 0.05). No significant differences were observed between the groups for MMP and kinematic parameters (p > 0.05). Conversely, it was found that all sizes and doses of NGO significantly protected post-thaw sperm regarding DNA integrity (p < 0.05). These findings indicate that the NGO, at a size of 50 nm and a dose of 50 µg/mL, improves the post-thaw quality of Angora buck sperm and provides a cryoprotective effect that depends on size and dose. This study provides preliminary data on the potential effects of NGO; however, comprehensive mechanistic and in vivo validation studies are required to establish the biological and clinical validity of these findings. Full article

Background/Objectives: Although anti-Müllerian hormone (AMH) is a strong biomarker of ovarian reserve and oocyte pools, it is unknown whether high AMH levels can be a reliable predictor of oocyte quality, ovulation, and embryo quality. We aimed to determine whether there is any AMH threshold value that can be used to predict treatment success in women with clomiphene citrate (CC) resistance or failure in polycystic ovary syndrome (PCOS). Methods: This retrospective cohort study included 93 infertile women with PCOS who had been previously diagnosed with CC failure or CC resistance between May 2017 and June 2018. Prior to treatment, AMH concentration was measured in all women. The participants were divided into 2 groups according to their conception after ovulation induction (OI) and intrauterine insemination (IUI). At the end of a one-year period, the medical files were assessed retrospectively. Those with and without pregnancy were compared in terms of treatment protocols, infertility periods, laboratory parameters and AMH levels. Results: Clinical and biochemical characteristics of 36 pregnant women were compared with those of 57 non-pregnant women. The results showed that the pregnant group had significantly shorter infertility periods and longer ovarian stimulations than the non-pregnant group (p < 0.05). Serum AMH levels > 4.5 ng/mL can predict OI and IUI outcome in this specific patient population, with a sensitivity of 56% and a specificity of 69%. Multivariate logistic regression analysis showed that only AMH was identified as an independent predictor of pregnancy [OR = 1.151 (95% CI: 1.034–1.280), p = 0.010]. Conclusions: Serum AMH may serve as an adjunct predictor of OI and IUI outcomes in infertile women with PCOS who failed to conceive after ≥3 cycles of CC. However, its predictive value appears to be context-dependent and should be interpreted cautiously in clinical practice. Given the distinct clinical characteristics of this patient population, individualized treatment strategies and consideration of earlier alternative therapeutic approaches may be warranted to optimize reproductive outcomes. Full article

Melatonin (MLT) is a potent antioxidant that reduces oxidative stress (OS)-induced sperm damage. However, few studies have explored its effects in the field investigated here. This study aimed to evaluate the effects of MLT supplementation in extenders used for staining, sorting, and freezing on the quality of sorted Nili-Ravi buffalo sperm, embryo development after in vitro fertilization (IVF), and pregnancy outcomes following artificial insemination (AI). Computer-aided sperm analyzer (CASA) showed that progressive motility (PM) and velocity parameters of sorted, frozen–thawed sexed sperm were higher in the MLT-treated groups (p < 0.05). Fluorescence microscopy demonstrated that MLT significantly improved sperm plasma membrane integrity after staining and increased the proportion of frozen–thawed sex-sorted sperm with high mitochondrial membrane potential (HMMP) (p < 0.05). Raman spectroscopy further identified several distinctive Raman bands at 936, 1300, and 1651–1652 cm⁻¹, which may serve as biomarkers for assessing sperm quality. Additionally, cleavage rate, blastocyst formation, and pregnancy rates following IVF and AI were higher in the MLT-treated group (p < 0.05). In conclusion, MLT can serve as a valuable additive during sperm sex-sorting procedures to enhance sperm quality, thereby improving embryo developmental competence and pregnancy outcomes. Full article

This review provides a comparative examination of current methods for evaluating fertility and semen quality in mammals, with emphasis on livestock species. It is based on a structured search and analysis of 316 academic publications retrieved from major scientific databases, including Elsevier, Springer, Taylor & Francis, and MDPI, as well as other repositories, covering literature published between 1938 and 2025. This review examines advanced semen analysis techniques, including computer-assisted semen analysis (CASA) systems and assays for assessing chromatin integrity, DNA damage, seminal plasma composition, sperm membrane proteins, and functional parameters such as migration capacity, membrane integrity, acrosomal status, capacitation, morphology, viability, concentration, motility, and volume. Methods for semen collection are also outlined. The synthesis focuses on the comparative assessment of techniques and recent findings for major ruminant and monogastric livestock species: cattle (Bos taurus and Bos indicus), buffalo (Bubalus bubalis), sheep (Ovis aries), goats (Capra hircus), and pigs (Sus domesticus). A brief historical overview of assisted insemination is presented, incorporating relevant procedures and managerial factors that affect fertility outcomes. Advances in genetics related to reproductive health are also discussed. This synthesis seeks to integrate existing knowledge and guide future research in reproductive science for both animal production and human medicine. Full article

Efficient liquid storage of turkey semen is critical for artificial insemination, but its use is limited by bacteriospermia and oxidative damage. This study evaluated the effects of gentamicin supplementation in Glutac and Sperm Motility Medium (SMM) on bacterial load and sperm quality after 2 and 24 h of liquid storage. Semen from turkeys (n = 40) was assessed for motility, viability, plasma membrane and acrosome integrity, mitochondrial and metabolic activity, oxidative profile, apoptosis, DNA integrity, and microbiological status. The sperm motility and kinematic parameters declined significantly after 24 h in all the groups. However, both extenders (particularly SMM) maintained significantly higher motility than the untreated control. Gentamicin further improved the motility, viability, and plasma membrane and acrosome integrity. The mitochondrial activity and mitochondrial membrane potential were significantly higher in the extender-treated groups than in the controls at 2 and 24 h, whereas the superoxide and total ROS production were significantly higher in the controls. The total antioxidant capacity declined markedly in the untreated controls, especially after 24 h. Gentamicin significantly reduced bacterial load, most effectively in SMM, and decreased DNA fragmentation compared with the untreated controls. In conclusion, gentamicin supplementation—particularly in SMM—reduces bacteriospermia and oxidative stress while preserving turkey sperm quality during liquid storage. Full article

This study investigated the effects of different PRP doses and application strategies on sperm quality in goats during cryopreservation. Semen samples were collected weekly from six Boer goats and treated with PRP either by means of pre-incubation or supplementation of the semen extender at concentrations of 10, 20, and 40 × 10⁶ platelets/mL. Computer-assisted sperm analysis (CASA) was performed after equilibration and again after thawing to assess sperm motility parameters, including progressive motility. Post-thaw sperm functional integrity was further evaluated using flow cytometry, including assessments of plasma membrane integrity, acrosome integrity, high mitochondrial membrane potential (hMMP), sperm viability, oxidative stress, and DNA integrity. The results demonstrated that pre-incubation with PRP at 10 × 10⁶ platelets/mL (pre-PRP10) yielded the most pronounced improvements in total and progressive motility after thawing, as well as in plasma membrane integrity, viability, and mitochondrial activity, while significantly reducing oxidative stress and DNA fragmentation compared with other PRP doses and application strategies. Supplementation of the extender with PRP at 20 × 10⁶ platelets/mL also showed favorable effects on functional sperm parameters; however, it did not result in significant improvements in oxidative stress or DNA fragmentation. In contrast, the highest PRP dose (40 × 10⁶ platelets/mL) did not confer additional benefits. None of the PRP treatments improved post-thaw acrosome integrity. In conclusion, these findings highlight the importance of PRP dose optimization and direct sperm–PRP interaction, identifying pre-incubation with PRP at 10 × 10⁶ platelets/mL as the most effective approach for enhancing post-thaw sperm quality in goats. Full article

The aim of this study was to comparatively evaluate echotextural and hemodynamic changes in the corpus luteum (CL), uterus, and uterine artery, together with serum progesterone (P4) concentrations, using B-mode and Doppler ultrasonography between days 5 and 21 post-insemination in pregnant and non-pregnant cows. Twelve clinically healthy Brown Swiss cows were enrolled and allocated into a cyclic non-inseminated group (n = 6) and an inseminated group (n = 6). Ultrasonographic examinations and progesterone measurements were performed daily during the post-insemination period, and pregnancy was confirmed on day 30. Echotextural parameters (mean gray value and homogeneity) were obtained from the corpus luteum and uterus using B-mode ultrasonography. Doppler ultrasonography was used to assess corpus luteum vascular parameters and uterine artery blood flow, and serum progesterone concentrations were measured at each examination. Corpus luteum mean gray value showed a significant time effect (p < 0.001). For Corpus luteum area and perfusion area, both the time effect and the group × time interaction were significant (p < 0.001), and marked differences between pregnant and non-pregnant cows were observed on days 19, 20, and 21 (p < 0.05). Serum progesterone concentrations also differed significantly between groups on days 20 and 21. In conclusion, changes in corpus luteum area and perfusion area were associated with early pregnancy-related differences and may represent earlier functional ultrasonographic indicators compared with uterine artery Doppler parameters and progesterone concentrations alone. These findings may have practical implications for herd management by potentially enabling differentiation between pregnant and non-pregnant cows approximately 1–2 days earlier than serum progesterone measurements. Full article