Advanced Reproductive Technologies Research Articles

P-461 Fertility knowledge, childbearing intentions and attitudes regarding parenthood among men and women about to get married in Iran

Abstract Study question What is the level of fertility knowledge, childbearing intentions, and attitudes toward parenthood among men and women who are about to get married in Iran? Summary answer The study revealed insufficient fertility knowledge, a strong desire for childbearing, and a positive attitude toward parenthood, along with significant gender disparities in fertility preferences. What is known already In recent years, declining birth rates in both developed and developing countries have raised concerns. The downward trend in fertility rates and delayed childbearing present significant global challenges related to aging populations, requiring an examination of contributing factors. Advances in reproductive technologies, evolving gender roles, and personal and professional aspirations have fundamentally reshaped attitudes towards fertility, influencing couples’ intentions to have children. A comprehensive understanding of individuals’ fertility knowledge and preferences regarding childbearing and parenting is essential to comprehend fertility behaviors and develop targeted interventions, family support systems, and policies aligned with their preferences. Study design, size, duration From June 2021 to March 2022, a web-based cross-sectional survey was conducted, involving 2938 soon-to-be-married individuals (1533 women and 1405 men). Participants/materials, setting, methods Women aged 18 to 35 years and men aged 18 to 45 years, with no history of prior marriages, who were referred to public health centers for the purpose of obtaining a marriage license, were included through stratified sampling in Iran’s five major cities (Tehran, Tabriz, Mashhad, Ahvaz, and Shiraz). The Cardiff Fertility Knowledge Scale (CFKS) and the Swedish Fertility Awareness Questionnaire were used for data collection. Main results and the role of chance The mean age among men and women was 28.86±5.44 and 24.61±5.99 years, respectively. The average CFKS score was 48.19% (0-100%) with no significant difference between males and females (48.08% vs 48.3%, p = 0.694). The study found that 86.6% of participants expressed an intention to have children in the future, significantly more prevalent among men compared to women (88.9% vs. 84.4%, p < 0.001). The desired family size was two children for 56.1% of participants, while 19.1% preferred one child. The intention of women to have the first and last child between the ages of 35 and 39 was 12.7% and 31%, respectively. Participants highly valued parenthood (7.76±2.90), and men valued parenthood significantly more compared to women (7.88 ±2.84 vs 7.64±2.96, p = 0.027). Participants viewed In Vitro Fertilization (IVF), adoption, and a child-free lifestyle as potential responses to infertility with respective ratings of 5.73±3.78, 4.04±3.63, and 3.99±3.63, respectively (range 0-10). No significant gender differences were observed (all p > 0.05). The study highlighted that maintaining a stable relationship was perceived as the most important factor influencing the decision to have children (4.54±1.05). Moreover, participants believed the most transformative aspects of parenthood were the giving and receiving of love (2.56±0.82). Limitations, reasons for caution Interpreting the results necessitates addressing limitations such as volunteer bias, urban area sampling, cross-sectional design limitations for causal relationships, and the potential influence of Covid-19 on fertility preferences. Therefore, caution is needed when generalizing findings to other populations. Wider implications of the findings The study’s findings have significant implications for policies promoting childbearing. To enhance fertility knowledge, promote informed reproductive decision-making, and facilitate consensus among couples regarding their fertility choices, it is recommended that midwives assume a crucial role in providing related services. These measures should be smoothly integrated into existing frameworks. Trial registration number Not applicable

Male Reproduction in Spinal Muscular Atrophy (SMA) and the Potential Impact of Oral Survival of Motor Neuron 2 (SMN2) Pre-mRNA Splicing Modifiers.

Spinal muscular atrophy (SMA) is a neuromuscular disease caused by deletions or mutations in the survival of motor neuron 1 (SMN1) gene resulting in reduced levels of SMN protein. SMN protein is produced by cells throughout the body, and evidence suggests that low SMN protein can have systemic implications, including in male reproductive organs. However, a paucity of research exists on this important topic. This article will discuss findings from non-clinical studies on the role of SMN in the male reproductive system; additionally, real-world observational reports of individuals with SMA will be examined. Furthermore, we will review the non-clinical reproductive findings of risdiplam, a small-molecule SMN2 splicing modifier approved for the treatment of SMA, which has widespread distribution in both the central nervous system and peripheral organs. Specifically, the available non-clinical evidence of the effect of risdiplam on male reproductive organs and spermatogenesis is examined. Lastly, the article will highlight available capabilities to assess male fertility as well as the advanced reproductive technologies utilized to treat male infertility. This article demonstrates the need for further research to better understand the impacts of SMA on male fertility and reproduction.

Advanced repro start-up

Advanced reproductive technologies (ART) and their respective services have been part of my repertoire since my childhood days. Flushing cows (in vivo collections) has been routinely per­formed on my family’s farm for decades. In more recent years, in vitro embryo production has become more prominently utilized by my farm as well as by my clients. Since purchasing Midwest Embryo Transfer Service in 2016, we have expanded the services offered to include: in vivo collections, ovum pick-up (OPU) for in vitro fertilization, fresh and frozen in vivo and in vitro embryo transfers, cryopreservation of both in vivo and in vitro embryos, and export services.

Emerging Contributions of Pluripotent Stem Cells to Reproductive Technologies in Veterinary Medicine.

The generation of mature gametes and competent embryos in vitro from pluripotent stem cells has been successfully achieved in a few species, mainly in mice, with recent advances in humans and scarce preliminary reports in other domestic species. These biotechnologies are very attractive as they facilitate the understanding of developmental mechanisms and stages that are generally inaccessible during early embryogenesis, thus enabling advanced reproductive technologies and contributing to the generation of animals of high genetic merit in a short period. Studies on the production of in vitro embryos in pigs and cattle are currently used as study models for humans since they present more similar characteristics when compared to rodents in both the initial embryo development and adult life. This review discusses the most relevant biotechnologies used in veterinary medicine, focusing on the generation of germ-cell-like cells in vitro through the acquisition of totipotent status and the production of embryos in vitro from pluripotent stem cells, thus highlighting the main uses of pluripotent stem cells in livestock species and reproductive medicine.

Gestational carrier cycles: embryology trends, national guideline compliance, and resultant perinatal outcomes in the United States, 2014–2020

The increased use of gestational carriers has expanded family-building opportunities for people and couples unable to carry pregnancies on their own. National American Society of Reproductive Medicine guidelines for gestational carriers have changed over time to reflect advances in reproductive technology and mounting evidence supporting the medical benefits associated with singleton gestations. Assess changes in gestational carrier cycle practice patterns and resultant pregnancy outcomes in the United States in relation to changing national American Society of Reproductive Medicine guidelines, which changed in 2013 and2017. This retrospective study used data from the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System and included all cycles that were reported from 2014-2020 involving an embryo transfer to a gestational carrier. Binomial regression models evaluated trends in preimplantation genetic testing for aneuploidy, American Society of Reproductive Medicine guideline adherence, number of embryos transferred, and pregnancy outcomes over time. Of the 40,177 gestational carrier transfer cycles from 2014-2020, there was a significant increase in frozen-thawed cycles (41.3% increase), use of assisted hatching (53.4% increase), intracytoplasmic sperm injection (50.0% increase), and preimplantation genetic testing for aneuploidy (155.7% increase). The likelihood of preimplantation genetic testing for aneuploidy was higher in 2020 than in 2014 for autologous oocyte transfers to gestational carriers, both for those aged ≥38 years (adjusted relative risk, 2.38 [95% confidence interval, 2.11-2.70]) and than those aged <38 years (adjusted relative risk, 2.85 [95% confidence interval, 2.58-3.15]). As preimplantation genetic testing for aneuploidy usage increased, single embryo transfer rose for both autologous (adjusted relative risk, 2.22 [95% confidence interval, 1.94-2.50]) and donor cycles (relative risk, 1.91 [95% confidence interval, 1.81-2.02]). This shift toward single embryo transfer corresponded with a decrease in multiple embryo transfer by 79.2% and subsequent decreases in multiple gestations by 68.8% in donor and 73.6% in autologous oocyte cycles from 2014-2020. Gestational carrier cycles remained highly adherent to changing American Society of Reproductive Medicine guidelines throughout the study period. Among live births, there was a 19.4% and 7.9% increase in term deliveries among donor and autologous oocyte cycles, respectively, from 2014 to2020. Practice patterns have drastically changed throughout the study period, with major increases in the use of preimplantation genetic testing for aneuploidy, intracytoplasmic sperm injection, assisted hatching, and frozen transfers. In response to changing American Society of Reproductive Medicine guidelines, the use of multiple embryo transfers has decreased for gestational carrier cycles with subsequent decreases in multiple gestations and miscarriages and slight increases in live birth rates.

Полисахариды базидиальных грибов повышают качество репродуктивных клеток быков при замораживании

The global decline in the animal and plant species diversity is among the key environmental problems of the modern world. One possible way to solve this problem is to develop advanced reproductive technologies using gametes to restore genetic diversity. Cryobanks play an important role in this. The traditional method of long-term storage of reproductive cells is their cryopreservation at –196оC using cryoprotective media based on synthesized substances (glycerin, dimethyl sulfoxide, etc.). The reason for searching new effective substitutes is cytotoxicity, impaired fertility and other disadvantages when using traditional cryoprotectors. In addition, it is relevant to expand the temperature range of biomaterial storage, in particular using the conditions of electric freezers. The wide range of biological effects of polysaccharides of basidiomycetes allowed us to make an assumption about the effectiveness of their use in the composition of the medium for cell cryopreservation. This paper presents the results of a comparative study of the effectiveness of polysaccharides of xylotrophic basidiomycetes in the composition of the medium for storage of the Holstein bull semen. The semen was frozen to –5оC and storaged at the specified temperature for 7 days in AndroMed® (Minitübe, Germany) – certified extender for freezing the semen of bulls and other ruminants. Additional introduction into its composition of polysaccharides from the basidiomycetes Hericium erinaceus BP16 / Ganoderma applanatum GA significantly improves the quality of reproductive cells in the used cryopreservation technology.

Congenital Anomalies of the Female Genital Tract: A Comprehensive Review.

This comprehensive review provides an in-depth examination of congenital anomalies of the female genital tract, explicitly focusing on the American Society for Reproductive Medicine (ASRM) Müllerian Anomalies Classification. The classification system is crucial for standardizing communication and guiding accurate diagnoses in clinical practice. The review explores the diverse clinical presentations, etiological factors, and diagnostic modalities associated with these anomalies. Management strategies, ranging from conservative approaches to advanced reproductive technologies, are discussed in the context of individualized treatment plans based on the ASRM classification. The psychosocial impact of female genital tract anomalies is thoroughly examined, emphasizing the importance of holistic care and patient-centered approaches. Looking toward the future, the review outlines emerging research areas, including advances in diagnosis techniques, innovative treatment modalities, and genetic studies. It ultimately underscores the need for a comprehensive understanding of physical and psychosocial dimensions, offering insights for healthcare professionals to navigate this complex landscape and improve the lives of affected individuals.

Genomic selection in dairy cattle: impact and contribution to the improvement of bovine fertility

Genomic selection has revolutionized the dairy cattle breeding industry, with ripple effects that have greatly impacted dairy herd management. Rate of genetic progress has increased markedly, especially in Holstein and Jersey breeds, for production, health, and fertility traits. Genomic testing of young bulls and heifers provides greater accuracy of selection decisions involving traditional fertility traits, such as daughter pregnancy rate, while creating the opportunity to improve novel traits, such as fetal loss. Cameras, wearable sensors, and other precision livestock farming technologies will allow selection for traits such as estrus duration and intensity that require high frequency phenotyping. At the same time, synergies between genomic testing and advanced reproductive technologies have led to rapid and widespread adoption of sexed semen, coupled with mating of females whose offspring are not needed as herd replacements to beef sires. This strategy produces added-value crossbred calves for the beef supply chain, while allowing genetically inferior mature cows that are still producing at a high level to remain in the herd for additional lactations.

Preimplantation genetic testing in the current era, a review.

Preimplantation genetic testing (PGT), also referred to as preimplantation genetic diagnosis (PGD), is an advanced reproductive technology used during in vitro fertilization (IVF) cycles to identify genetic abnormalities in embryos prior to their implantation. PGT is used to screen embryos for chromosomal abnormalities, monogenic disorders, and structural rearrangements. Over the past few decades, PGT has undergone tremendous development, resulting in three primary forms: PGT-A, PGT-M, and PGT-SR. PGT-A is utilized for screening embryos for aneuploidies, PGT-M is used to detect disorders caused by a single gene, and PGT-SR is used to detect chromosomal abnormalities caused by structural rearrangements in the genome. In this review, we thoroughly summarized and reviewed PGT and discussed its pros and cons down to the minutest aspects. Additionally, recent studies that highlight the advancements of PGT in the current era, including their future perspectives, were reviewed. This comprehensive review aims to provide new insights into the understanding of techniques used in PGT, thereby contributing to the field of reproductive genetics.

Lowering the cost of fertility treatments; a reality or a mirage?

In recent years, the rising costs associated with in vitro fertilization (IVF) have become a significant concern, limiting access to assisted reproductive technologies for many aspiring parents. The rising financial burden on patients seeking assisted reproductive technologies necessitates a focused exploration of potential causes and strategic interventions to make IVF more economically accessible. The escalating cost of IVF poses a multifaceted challenge rooted in several contributing factors. Advances in reproductive technologies, the need for specialized medical expertise, and stringent regulatory requirements collectively drive up the overall expenses associated with IVF procedures. Increased demand for specialized personnel, sophisticated laboratory equipment, and adherence to stringent quality assurance measures. Moreover, the intricate nature of IVF procedures, coupled with the need for extensive hormonal stimulation and monitoring, adds to the economic burden on both healthcare providers and patients. There is a need to delve into pragmatic approaches to lower IVF costs, emphasizing collaboration and innovation. Optimization of laboratory processes, integration of artificial intelligence for predictive modeling, and standardization of protocols to streamline procedures without compromising success rates. Additionally, discussions encompass potential collaborations between the public and private sectors to foster shared responsibility and explore avenues for cost sharing. By fostering collaborative efforts and implementing innovative strategies, the aim is to make assisted reproductive technologies more financially feasible for a broader spectrum of individuals, ultimately advancing accessibility and affordability in reproductive medicine.

Recent Advances in Dairy Animal Breeding and Reproduction: A Review

This review has highlighted the transformative impact of recent technologies on dairy animal breeding and reproduction. Recent advances in the breeding and reproduction of dairy cows involve the integration of molecular genetics, cytogenetics, and reproductive biology into animal breeding practices. This integration of precision technologies has played a critical role in increasing the efficiency and productivity of breeding programs. The development of modern genetic technologies, such as genome mapping, marker-assisted selection, and transgenesis, has revolutionized the identification of superior genetic traits, contributing to accelerated genetic progress in dairy herds. Furthermore, advancements in reproductive technologies, including artificial insemination, embryo transfer, sperm sexing, and synchronization of estrus and ovulation in dairy cows, have supported the optimization of breeding strategies and facilitated improvements in economically important traits in livestock. Efforts have also been directed toward advancing the early detection of estrus stress in dairy cows using sensitive physiological indicators and sensor technologies, aiming to enhance decision-making in estrus management on dairy farms. In conclusion, recent improvements in the breeding and reproduction of dairy animals have demonstrated significant potential for enhancing reproductive efficiency, profitability, and the quality of milk and milk products. However, these technologies face limited applicability in developing countries due to challenges such as poor infrastructure, low costs, or a lack of human resources. Therefore, it is imperative to develop cost-effective technologies tailored to local and regional contexts, subsequently facilitating their broad dissemination within these regions.

Bridging the Gap: Animal Models in Next-Generation Reproductive Technologies for Male Fertility Preservation.

This review aims to explore advanced reproductive technologies for male fertility preservation, underscoring the essential role that animal models have played in shaping these techniques through historical contexts and into modern applications. Rising infertility concerns have become more prevalent in human populations recently. The surge in male fertility issues has prompted advanced reproductive technologies, with animal models playing a pivotal role in their evolution. Historically, animal models have aided our understanding in the field, from early reproductive basic research to developing techniques like artificial insemination, multiple ovulation, and in vitro fertilization. The contemporary landscape of male fertility preservation encompasses techniques such as sperm cryopreservation, testicular sperm extraction, and intracytoplasmic sperm injection, among others. The relevance of animal models will undoubtedly bridge the gap between traditional methods and revolutionary next-generation reproductive techniques, fortifying our collective efforts in enhancing male fertility preservation strategies. While we possess extensive knowledge about spermatogenesis and its regulation, largely thanks to insights from animal models that paved the way for human infertility treatments, a pressing need remains to further understand specific infertility issues unique to humans. The primary aim of this review is to provide a comprehensive analysis of how animal models have influenced the development and refinement of advanced reproductive technologies for male fertility preservation, and to assess their future potential in bridging the gap between current practices and cutting-edge fertility techniques, particularly in addressing unique human male factor infertility.

Development and evaluation of a decision-making aid for couples hesitant about transitioning from infertility treatment to advanced assisted reproductive technology: a usability and feasibility study

ObjectivesThe aims of this study were (1) to develop a decision-making aid for couples hesitant about transitioning from infertility treatment to advanced assisted reproductive technology, (2) to examine the adequacy of this aid, and (3) to evaluate its usability. After the first version of the decision-making aid was created, the first version was supervised and finally a prototype of the decision-making aid was completed. We conducted a feasibility study from February to March 2022. We used a quantitative cross-sectional descriptive design involving 22 medical professionals and infertility survivors recruited.ResultsTwenty-two participants (3 reproductive medical specialists, 11 nurses who specialize in reproductive medicine, and 8 infertility survivors) were included in the final analysis (91.7% valid response rate). Of these participants, 81.8% answered Agree regarding “Easy-to-read degree of charts”, 17 (77.3%) answered It is just the right amount regarding “Appropriateness of information volume”, 81.8% answered Agree regarding “Ease of understanding content”, and 90.9% answered Good regarding “Overall performance”. From the opinions received, we extracted 4 categories: “Useful for decision making,” “Suitable for providing information,” “Useful in clinical practice,” and “Needs improvement.” Certain degrees of surface validity and content validity were confirmed for the trial version of the decision-making aid.

#295 : Comparison of In Vitro Fertilization in Couples with HIV Infection with Negative Viral Load Versus Non-Infected Couples: A Case-Control Study

Background and Aims: The development of Advanced Reproductive Technology (ART) changes many aspects and perspectives towards reproductive health. Current in vitro fertilization (IVF) protocols reduce the risk of Human Immunodeficiency Virus (HIV) transmission to their partners and offspring. This study compares IVF outcome in couples in which at least one partner is HIV positive with negative viral load versus couples in which neither partner is diagnosed with HIV. Method: A total of 100 couples undergoing IVF were categorized into two groups. HIV-positive with negative viral load group in which at least one partner is infected (n = 50) and non-HIV group in which neither partner is diagnosed with HIV (n = 50) are collected from medical record in our center during the same period. The main outcomes were total oocyte retrieved, normal fertilized egg or 2 pronucleus (2PN) one day after fertilization and good quality embryos based on number of embryos that transferred and frozen for IVF procedure. Differences between groups were determined statistically using the Mann-Whitney test. Results: There is a significant difference between HIV-positive with negative viral load groups compared to non-HIV groups in terms of total oocyte retrieved (p = 0,005) and normal fertilized egg one day after fertilization (p = 0.017). There is no significant difference in the number of good quality embryos (p = 0.076) between two groups. Conclusion: The data suggested that couples with HIV-positive women have poorer total oocyte retrieved and normal fertilized egg outcome compared to non-HIV couple. HIV infection might affect success rates of IVF treatments.

A Comprehensive Genetic Study of Microtubule-Associated Gene Clusters for Male Infertility in a Taiwanese Cohort.

Advanced reproductive technologies are utilized to identify the genetic mutations that lead to spermatogenic impairment, and allow informed genetic counseling to patients to prevent the transmission of genetic defects to offspring. The purpose of this study was to identify potential single nucleotide polymorphisms (SNPs) associated with male infertility. Genetic variants that may cause infertility are identified by combining the targeted next-generation sequencing (NGS) panel and whole exome sequencing (WES). The validation step of Sanger sequencing adds confidence to the identified variants. Our analysis revealed five distinct affected genes covering seven SNPs based on the targeted NGS panel and WES data: SPATA16 (rs16846616, 1515442, 1515441), CFTR (rs213950), KIF6 (rs2273063), STPG2 (r2903150), and DRC7 (rs3809611). Infertile men have a higher mutation rate than fertile men, especially those with azoospermia. These findings strongly support the hypothesis that the dysfunction of microtubule-related and spermatogenesis-specific genes contributes to idiopathic male infertility. The SPATA16, CFTR, KIF6, STPG2, and DRC7 mutations are associated with male infertility, specifically azoospermia, and a further examination of this genetic function is required.

The neonatal southern white rhinoceros ovary contains oogonia in germ cell nests

The northern white rhinoceros is functionally extinct with only two females left. Establishing methods to culture ovarian tissues, follicles, and oocytes to generate eggs will support conservation efforts using in vitro embryo production. To the best of our knowledge, this is the first description of the structure and molecular signature of any rhinoceros, more specifically, we describe the neonatal and adult southern white rhinoceros (Ceratotherium simum simum) ovary; the closest relation of the northern white rhinoceros. Interestingly, all ovaries contain follicles despite advanced age. Analysis of the neonate reveals a population of cells molecularly characterised as mitotically active, pluripotent with germ cell properties. These results indicate that unusually, the neonatal ovary still contains oogonia in germ cell nests at birth, providing an opportunity for fertility preservation. Therefore, utilising ovaries from stillborn and adult rhinoceros can provide cells for advanced assisted reproductive technologies and investigating the neonatal ovaries of other endangered species is crucial for conservation.

Comparative reproduction of the female horse, elephant and rhinoceros: implications for advancing Assisted Reproductive Technologies (ART).

Recent loss of rhinoceros subspecies has renewed interest in using more advanced assisted reproductive technologies (ART) in rhinoceroses and elephants. Currently, only semen collection, semen preservation and artificial insemination (AI) have been used repeatedly with success in these species. Although ovum pick-up (OPU) and intra-cytoplasmic sperm injection (ICSI) have been reported in rhinoceroses, the techniques are not yet optimised. In contrast, multiple ART applications are routinely used in the horse. Since elephant and rhinoceroses share some reproductive features with equids, we postulate that procedures such as OPU, ICSI, in vitro fertilisation (IVF) and embryo transfer (ET), which are well established in the horse, may represent a basis to develop protocols for endangered pachyderms. In this review, we summarize current knowledge on reproductive physiology relevant to ART. We discuss the current state of ART in all three families and the requirements for the successful implementation of OPU, ICSI, IVF and ET in these species.

Heat Stress as a Barrier to Successful Reproduction and Potential Alleviation Strategies in Cattle.

In recent decades, the adverse effects of global warming on all living beings have been unanimously recognized across the world. A high environmental temperature that increases the respiration and rectal temperature of cattle is called heat stress (HS), and it can affect both male and female reproductive functions. For successful reproduction and fertilization, mature and healthy oocytes are crucial; however, HS reduces the developmental competence of oocytes, which compromises reproduction. HS disturbs the hormonal balance that plays a crucial role in successful reproduction, particularly in reducing the luteinizing hormone and progesterone levels, which leads to severe problems such as poor follicle development with a poor-quality oocyte and problems related to maturity, silent estrus, abnormal or weak embryo development, and pregnancy loss, resulting in a declining reproduction rate and losses for the cattle industry. Lactating cattle are particularly susceptible to HS and, hence, their reproduction rate is substantially reduced. Additionally, bulls are also affected by HS; during summer, semen quality and sperm motility decline, leading to compromised reproduction. In summer, the conception rate is reduced by 20-30% worldwide. Although various techniques, such as the provision of water sprinklers, shade, and air conditioning, are used during summer, these methods are insufficient to recover the normal reproduction rate and, therefore, special attention is needed to improve reproductive efficiency and minimize the detrimental effect of HS on cattle during summer. The application of advanced reproductive technologies such as the production of embryos in vitro, cryopreservation during the hot season, embryo transfer, and timed artificial insemination may minimize the detrimental effects of HS on livestock reproduction and recover the losses in the cattle industry.

Improving national fertility evaluations by accounting for the rapid rise of embryo transfer in US dairy cattle

Dairy producers have improved fertility of their herds by selecting bulls with higher conception rate evaluations. This research was motivated by the rapid increase in embryo transfer (ET) use to 11% of recent births and >1 million total births, with >5 times as many ET calves born in the United States in 2021 compared with just 5 yr earlier. Historical data used in genetic evaluations are stored in the National Cooperator Database. Recent records in the national pedigree database revealed that only 1% of ET calves have corresponding ET records in the breeding event database, 2% are incorrectly reported as artificial inseminations, and 97% have no associated breeding event. Embryo donation events are also rarely reported. Herd years reporting >10% of calves born by ET but less than half of the expected number of ET breeding events were removed to avoid potential biases. Heifer, cow, and sire conception rate evaluations were recalculated with this new data set according to the methods used for the official national evaluations. The edits removed about 1% of fertility records in the most recent 4 yr. Subsequent analysis showed that censoring herd years with inconsistent ET reporting had little effect on most bulls except for the highest ranking, younger bulls popular for ET use, and with largest effects on genomic selection. Improved ET reporting will be critical for providing accurate fertility evaluations, especially as the popularity of these advanced reproductive technologies continues to rise.

Optimization of a non-activating medium for short-term chilled storage of barramundi (Lates calcarifer) testicular spermatozoa

Reliable short-term chilled sperm storage is a critical prerequisite to using advanced reproductive techniques for captive breeding of barramundi (Asian sea bass; Lates calcarifer). Marine Ringer's solution (MRS) is a common non-activating medium (NAM) and has previously been used to store sperm from wild-caught barramundi. However, MRS-stored spermatozoa from captive-bred barramundi were observed to lyse within 30 min incubation. Therefore, this study aimed to optimize the composition of NAM for short-term chilled storage by characterizing and mimicking the biochemical profile of seminal and blood plasma of captive-bred barramundi. To further understand the effect of each component, osmolality was first examined to determine its effect on sperm viability. Thereafter, the effects of NaHCO3, pH, and Na+ and K+ concentrations on sperm motility were investigated. Optimization of the NAM formula was achieved through iterative adaptions. The increase in NAM osmolality from 260 to 400 mOsm/kg led to a significant improvement in sperm viability. Moreover, using HEPES instead of NaHCO3 as buffering agent significantly enhanced sperm motility and velocity. As a result, sperm samples diluted with optimized NAM (185 mM NaCl, 5.1 mM KCl, 1.6 mM CaCl2·2H2O, 1.1 mM MgSO4·7H2O, 10.0 mM HEPES, 5.6 mM D+ glucose, 400 mOsm/kg, pH 7.4) and stored at 4 °C showed no significant loss in total motility for up to 48 h and retained progressive motility for up to 72 h. The optimized NAM developed in this study significantly extended the functional lifespan of spermatozoa during chilled storage, permitting the ongoing development of advanced reproductive technologies for barramundi.