Duration: 10/01/2026 to 09/30/2031

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Reproductive efficiency is a primary driver of profitability, stability, and long-term viability in U.S. livestock production. Fertility challenges in cattle and sheep, including delayed puberty, failed breeding, pregnancy loss, and reduced survival of young animals, result in fewer animals produced, higher production costs, and reduced lifetime productivity of breeding stock. These challenges arise from interactions among animal biology, genetics, management practices, and variable production conditions across regions. The W5112 multistate project brings together scientists from universities nationwide to improve understanding and management of reproduction in domestic ruminants through coordinated, collaborative research. By combining expertise across states, the project links fundamental research with applied studies that directly address producer-identified constraints to reproductive performance.

Consistent with its objectives, W5112 will improve understanding of how eggs and sperm develop and function, how management practices and stress affect puberty, breeding success, and pregnancy, and how both the female and male contribute to the early growth and survival of calves and lambs. This work will identify the key factors that determine whether animals conceive on time, stay pregnant, deliver healthy offspring, and remain productive in the herd for longer.

Collectively, W5112 outcomes will provide producers and industry stakeholders with actionable information to improve selection of females to retain in the herd, breeding decisions, optimize use of reproductive technologies, reduce pregnancy loss, and increase consistency of reproductive performance across diverse production systems with a focus on reproductive longevity. These improvements support efficient food production, economic stability for producers, and resilient livestock systems. In addition, W5112 will contribute to workforce development by training undergraduate and graduate students, postdoctoral scholars, and early-career scientists, strengthening capacity in reproductive science and applied livestock research that supports U.S. agriculture.

Statement of Issues and Justification

The W-112 Regional Research Project was originally established in 1970 to create a cooperative research group that combines both basic and applied expertise to identify mechanisms and subsequently develop methods to improve the fertility of domestic ruminants in the Western states.  The philosophy and mission for the W-112 established fifty years ago, continues to be the guiding tenet of our group; that is, cooperative multi-state research, which provides novel information to aid in product and technique development and outreach for the benefit of animal producers in the Western region and across the nation. 

The W5112 project serves as a forum for the development and execution of collaborative studies and sharing of data aimed at identifying and solving problems that limit the reproductive performance of domestic livestock. Scientists associated with the project collectively possess the expertise required to discover basic physiological mechanisms and translate such new knowledge into their application within management of domestic ruminants.  Some stations are best equipped to evaluate basic science questions that may lead to the enhancement of management practices or techniques that influence management decisions.  In contrast, other stations have the animal resources to test new treatment paradigms arising from the basic studies, but do not have the laboratory facilities (or modern equipment) necessary to perform the basic research studies.  These circumstances create an ideal situation for our regional collaborative projects and have been capitalized on by project members, leading to numerous collaborations among many university agriculture experiment stations and USDA agriculture research station scientists.  Renewal of the W-112 Regional Research Project (W5112) is crucial because interactions among scientists with a broad range of expertise are necessary for the discovery, translation, and transfer of new knowledge to the livestock industry. Suggestions, discussion, and critical review of experiments are also part of the annual meetings for W-112. Often this also leads to service on graduate student committees, external review of promotion and tenure packets, nomination for awards, or nominations of candidates for administrative positions, and exchange/nominations of graduate or undergraduate students for mentorship toward degrees.  

Poor reproductive efficiency of domestic ruminants limits the profitability and sustainability of animal production systems in the West and throughout the nation.  Therefore, we seek to continue our work in this critical area.  Participation in the project since its inception has greatly increased in scope and is now comprised of scientists located in 21 states, including: Arizona, California, Colorado, Connecticut, Florida, Illinois, Iowa, Kentucky, Mississippi, Missouri, Montana, Nebraska, New Mexico, Ohio, Pennsylvania, South Dakota, Texas, Utah, Washington, Wisconsin, and Wyoming.  We know the reproductive challenges of livestock producers have commonalities and are best addressed by combining the expertise and resources from multiple states with different environmental and resource ecosystems.  The addition of leading reproductive biologists from states outside the West has increased the breadth and greatly strengthened the scientific expertise of W112.  The W112 regional project has also welcomed those whose main interests are nutritional or provide analysis of big data to increase our breadth and ability to determine key genomic indicators or physiological processes that impact reproduction and may lead to the development of tools to enhance reproductive success. Renewal of this multi-state project is essential to continue to provide a forum that stimulates the development of new hypotheses, direction of new collaborative research projects, sharing of resources, and the identification and testing of new methods to manage reproduction in domestic ruminants. 

The livestock industry is a critical component of production agriculture in the states represented by scientists involved with the W5112 project. The dairy, beef, and sheep industries together contribute approximately $163 billion in farm receipts and an estimated overall production value of $243 billion.  In addition, direct and indirect employment related to the production and processing of these animals or their products supports over 2.3 million jobs (Knight, 2025; NCBA, 2025; Carlin, 2025; Shiflett, J.S. 2008). Over 60 percent of the nation’s breeding cows (beef and dairy) and 70 percent of the US breeding ewe inventory exist in states represented by participating W5112 scientists (USDA, 2025). 

W5112’s goals are consistent with the USDA 2022-2026 Strategic Plan. Specific objectives or goals addressed by the project include Strategic Goal 3 (Foster an Equitable and Competitive Marketplace for All Agricultural Producers) and Strategic Goal 4 (Provide All Americans Safe, Nutritious Food). Our primary stakeholder is the scientific community. From that community, it is our expectation that livestock producers will benefit. Application of basic advances requires time and involvement of extension educators. It is the aim of the W5112 project to effectively transfer the gain of knowledge to this audience through scientific publications and presentations to scientific, extension, and producer audiences. Individually, many research stations have annual or twice-yearly meetings with extension educators to implement technology transfer of new ideas, concepts, and the development of tools to producers. In addition to these methods, the W5112 members will seek out other ways, such as Beef Reports, articles in magazines such as “Beef “ or newsletters such as “Beef Watch”, the Dairy Cattle Reproduction Council, and websites- beef.unl.edu to report and share the data and information that they have produced.

Reproductive efficiency is widely regarded as the most limiting factor to profitability in animal production systems.  Nowhere is this more evident than in the modern dairy industry.  Loss of efficiency also impacts beef producers due to delayed onset of puberty, extended postpartum anestrus, low fertility, and consequently lighter calves at weaning.  Beef cattle production is the largest sector of animal agriculture in the United States, accounting for the largest share of total cash receipts for agricultural commodities and in 2024 it represented 22 percent of the $515 billion in total cash receipts for ag commodities (USDA-ERS, 2025). In the beef industry alone, the cost of infertility to U.S. producers has been estimated to be over $1.06 billion annually (Lamb, et al., 2008). Sheep producers also miss out on the potential for added revenue by not realizing the genetic potential for lambing rates in their flocks.  Finally, new challenges are faced by farms and ranches managing domesticated exotic ruminants whose reproductive physiology is relatively unknown.

Sub-optimal reproductive efficiency of domestic ruminants and feed costs associated with producing those animals are major obstacles to maintaining the profitability and sustainability of livestock production enterprises.  Up to 70 percent of costs associated with producing viable offspring can be attributed to feed required to maintain their dams during gestation.  Likewise, decreased fertility resulting from delayed onset of puberty, prolonged postpartum anestrous intervals, early embryonic mortality, and seasonality of breeding continues to limit production.  One of the objectives of our work in W5112 is to provide scientific and technical expertise that will encourage the development and application of science-based management tools to improve the productivity, efficiency, and profitability of livestock producers. In the current project plan, we expect to increase our efforts to bring knowledge to producers and help them make decisions based on sound science while expanding our understanding of factors that affect reproductive efficiency.  

For the current project, research will be focused on the following main areas: puberty and reproductive longevity, mechanisms of gamete development, ovulation and potential causes of anovulation, establishment and maintenance of pregnancy, fetal development/prenatal programming that affects fetal development, and male reproduction.  The technical feasibility of this work is strongly supported by the project’s long history of productivity, established animal and in vitro models, proven collaborative workflows, and the demonstrated ability of participating stations to translate basic discoveries into applied management strategies. In addition, the project directly addresses emerging challenges in livestock production, including climate-related stressors, epigenetic and developmental programming of fertility, and the growing need for precision livestock and reproductive management tools to support resilient production systems. Collectively, this work directly addresses USDA priorities by advancing producer profitability, food security, and sustainable livestock production through science-based reproductive management strategies.

If this work is not continued, critical gaps will persist in our understanding of the biological mechanisms governing fertility, limiting the development of science-based management tools, diagnostics, and genetic selection strategies needed to improve reproductive outcomes. Successful completion of the renewed W5112 project is expected to yield measurable impacts, including improved reproductive efficiency, reduced pregnancy loss, enhanced selection of fertile sires and dams, and improved offspring health and productivity. Collectively, these outcomes will strengthen the profitability, sustainability, and resilience of livestock production systems while advancing fundamental knowledge in reproductive biology.

Related, Current and Previous Work

Justification of project state members: In general, the states participating in the W112 project have been in the arid western states, which have reduced vegetation compared to other states. However, as environmental conditions across the U.S. have changed, our membership has also shifted, as challenges related to reduced vegetation have emerged in both flood-prone and arid regions. Furthermore, extreme environmental events have not been confined to the western region but have also cropped up in other parts of the US (i.e., tornadoes in the eastern half of the US). Resilience and ability to pivot are criteria that are now part of all states, including those outside of our region. As these environmental changes have occurred, we have increased our membership in states throughout the US. While approaches to improve reproductive efficiencies may still be different in the Western region vs North Central and Eastern, i.e., the size of pastures and animal carrying capacity, types of grasses grown, and rainfall comparisons of different management techniques have seemed just as important to our group. Also, as universities have reduced their animal resources available for research, this has enabled our group to retain enough animal numbers within the group to test different management strategies and tools to increase reproductive efficiencies.

Related multistate projects: Several multistate projects intersect with components of W5112. NE2227 addresses ovarian/uterine/embryo contributions to pregnancy success in ruminants; W5171 focuses on germ cell and embryo development/manipulation and technologies (including genetically altered livestock); and stress-focused multistate efforts target broader stress biology and mitigation strategies across species.  W5112 does not duplicate these efforts; rather, it complements them by emphasizing (1) domestic ruminant fertility as a unified system spanning gametes,  pregnancy, and offspring, (2) paired mechanistic + applied validation across diverse production settings, and (3) multistate coordination that enables dataset pooling and cross-environment robustness. Where topical overlap exists (e.g., pregnancy loss, gamete biology, stress), W5112 adds value through integration across objectives and stations, multistate synthesis, and translation to ruminant production systems.

Productivity of during the W4112 project period: Participating scientists established a productive and nationally competitive multistate research and training program addressing reproductive efficiency, pubertal attainment, anovulation (ovarian function), pregnancy establishment, fetal development, testis and sperm function, along with sire fertility in domestic ruminants. Collectively, W4112 investigators secured over $30 million in federal research funding as principal investigators or co-investigators, primarily through competitive programs administered by USDA-NIFA and the National Institutes of Health. This sustained level of federal support reflects both the quality of science and the value of the multistate framework for addressing complex reproductive challenges across species, environments, and production systems. This amount of federal, state, and industry funding resulted in 313 peer-reviewed publications, 328 abstracts, and 28 theses or dissertations.

A major achievement has been its contribution to workforce development. Across participating stations, the project supported the training of more than 120 graduate students and postdoctoral scholars, including approximately 70 M.S. students, 40 Ph.D. students, and over 25 postdoctoral researchers, in addition to extensive undergraduate research engagement. Training under W4112 was further strengthened by success in competitive federal training programs. Investigators mentored at least 15 federally funded predoctoral and postdoctoral trainees, supported by awards including USDA National Needs Graduate Fellowships, USDA-NIFA Predoctoral and Postdoctoral Fellowships, NIH F31 and F32 awards, and NIH T32 training slots. These outcomes demonstrate the strength of the mentoring environment and the national relevance of the training provided.

Related, current and previous research by members of W4112 is based on the premise that applied research experiments stem from a foundation of previous basic research studies. Studies reported herein, therefore, describe the discovery of mechanisms that regulate reproduction and the translation of those results into methods to improve reproductive performance in domestic ruminants. The list of research achievements, publications, and student theses and dissertations is extensive (as stated above).  Although it is not possible to detail each significant accomplishment, a summary of the major advances is provided below.

Major Advances from W4112:

 Biology of the Hypothalamic-Pituitary-Gonadal Axis.  

• Ovulation in mammals is caused by hormones released from the brain and the pituitary gland. Adequate and timely release of these hormones is essential for female fertility, and disruption of hormone release can lead to infertility. Multistate members are discovering the mechanisms that regulate hormone release to induce ovulation. A suite of upregulated genes has been identified in the pituitary gland that may facilitate hormone release and activate neurons during ovulation. These studies contribute to our basic understanding of hormone release for ovulation, which may yield new strategies to improve overall fertility in ruminants.

 Ovarian Biology and Follicle Development and CL function

• In livestock, infertility due to gamete quality contributes to loss of profit for producers. Multiple cellular, physiological, and endocrine mechanisms regulate gamete development and quality, necessary for fertility among livestock. Research from this multistate group demonstrates that inefficient energy metabolism of cells contributes to oocyte incompetence. In males, non-classical progesterone receptors, PGRMC2 and 2 are required for male fertility, and PRAMEY may be a biomarker of fertility. By identifying processes that affect gamete quality, incidence of infertility can be improved.
• Evidence was produced that preantral follicles, although not FSH-dependent, express FSH receptors and the cellular machinery necessary to respond to FSH, and the supplementation of high doses of FSH enhances growth of preantral follicles within the ovarian cortex. This information may be utilized to manage follicle selection and/or growth to improve egg quality or ART procedures.
• In cows, ovarian androgen excess often results in female infertility due to anovulation. Cows with excess ovarian androgen have a 17% reduction in calving rate and are found in herd in different parts of the US, in dairy and sheep in other countries (Jordan) supporting the notion that excess ovarian androgens contribute to reduced fertility in cow herds. These excess ovarian androgen cows have similar characteristics to women diagnosed with a reproductive disorder, polycystic ovary syndrome. Ovarian tissue treated in vitro with a growth factor, VEGFA165, ameliorates the ovarian androgen excess and allows follicles (which contain the egg) to grow and develop. Reducing the effects of androgen would enhance reproductive performance of approximately 15% of cow herds across the US. Information gleaned from these studies would be translatable to women in treating PCOS-like disorders.
• The corpus luteum is critical for the production of progesterone, which is necessary to maintain pregnancy. This structure arises from the granulosa and theca cells after ovulation of the oocyte (egg) within the follicle on the ovary. Investigators in the W4112 group determined that subcutaneous delivery of Interferon Tau protects the ovine corpus luteum from exogenously delivered prostaglandin F2-alpha by increasing genes that inhibit corpus luteum regression. Corpus luteum regression or luteolysis has also been associated with metabolic pathways that reduce mitochondrial energy production and stimulation of free radicals as well as collagen synthesis and immune cell activation. Understanding how the corpus luteum is maintained and regressed will allow for better maintenance of pregnancy in domestic livestock.
• Understanding the development of the oocyte is restricted by available in vitro technologies. Organoid structures are developed from ovarian dissociated cells and used for in vitro systems to study developing oocytes, follicles and corpus luteum. Several stations in W4112 are perfecting these organoid structures so that the development of the oocyte, follicle and corpus luteum can be studied in detail. These studies will lead to developing and selecting higher quality oocytes, understanding follicular progression and development, and regression of the corpus luteum thereby improving assisted reproductive technologies, folliculogenesis, and maintenance of pregnancy.

 Puberty

• The sooner livestock can attain sexual maturity the sooner they can produce offspring for economic benefit and the more likely they have increased longevity to stay in the herd. A selection system based on red blood cell parameters may identify delayed puberty in heifers. Once puberty is attained, ovulation results in an egg, which is varied in its ability to be fertilized. The administration of a hormone that promotes follicle production has promise to improve successful fertilization. In addition, new methods for cryopreservation of unfertilized cow eggs will have application to improve in vitro fertilization. These basic biological mechanisms are important to improve systems of estrous synchronization and artificial insemination in beef cattle.
• The development of heifer pubertal classes has allowed for a better understanding of why some heifers may have delayed puberty. Furthermore, these heifer puberty classifications are highly heritable and allow for the identification of single nucleotide polymorphisms and inflammation that may also contribute to delayed puberty. Altering the endocrine environment via different nutritional supplements has also been shown to advance puberty. Thus, genetics and environment as well as nutritional inputs, can affect the attainment of puberty in cattle.

 Oocyte-Embryo-Uterine Physiology.

• Advancements in ART have been supported by research into IGF signaling in conceptuses, which informs improvements of “in vitro” production (IVP) methodologies. Genetic studies have linked sire genetics and embryo phenotypes to fertility outcomes, enabling better selection strategies. Biomarkers and SNPs have been identified to predict embryo development success, and AI-driven estrus detection has improved embryo transfer timing. These innovations enhance the efficiency and success rates of ART, contributing to more sustainable breeding practices.
• Critical genes such as PRAME/PRAMEY and PGRMC1/2 influence embryo development, and reproductive lifespan. Trophoblast gene networks have been shown to play essential roles in pregnancy establishment, and PAGs have been identified for their involvement in embryo–maternal communication. These findings enhance our understanding of the molecular underpinnings of fertility and provide targets for improving reproductive outcomes.
• In the uterus, sperm further develop so they are capable of fertilization. Failure of this development results in reduced pregnancy rates. Several stations in W4112 have determined that release of zinc ions is necessary for this process and can be used to evaluate sperm quality. The use of higher quality sperm in assisted reproductive technologies will increase fertilization rates, embryo development, and establishment of pregnancy.
• In ruminant livestock animals such as cattle and sheep, infertility due to gamete quality and anovulation poses an economic strain on the producer. Research from this multistate group has worked to identify how stressors such as obesity, immune responses, and bacteria within the vagina disrupt proper ovulation and fertilization mechanisms that ultimately result in reproductive failure or the inability to establish a pregnancy in ruminants.
• Embryo quality and early embryo development are markers of male fertility and improved embryo transfer success. Early embryo development and embryo quality through diagnostic markers have demonstrated value in evaluating male fertility and improving pregnancy success following embryo transfer. Artificial insemination and embryo transfer are assisted reproductive technologies that allow producers to accelerate genetic improvements in their herds. These advances may also improve pregnancy success among humans experiencing infertility.

 Testicular and Sperm Physiology.

• Progesterone receptor membrane component (PGRMC) 1 and PGRMC2 are essential for spermatogenesis and male fertility. It is proposed that PGRMC proteins play essential and multifaceted roles in spermatogenesis during mitosis, meiosis and spermatid elongation. These studies offer the first in vivo insights into the functional role of PGRMC proteins in male gametogenesis and could lead to better management of spermatogenesis in different environments.
• Dominance hierarchy in rams does not significantly affect reproductive success in multi-sire systems. The value of a breeding soundness evaluation, as evidenced by ram fertility is still lacking. Passing a breeding soundness evaluation did not seem indicative of field fertility in rams. Thus, work is being conducted to determine how to better detect and preserve ram fertility.
• Bull breed appears to have little influence on sperm quality assessments among yearling bulls meeting threshold requirements for passing breeding soundness evaluation exams. However, reactive oxygen species proved to have a detrimental effect on spermatozoa function. Methods are being developed to reduce ROS in spermatozoa during semen collection and freezing protocols, including the use of oral melatonin supplementation during fall-winter to improve sperm motility in bulls.
• Male fertility prediction improves livestock operations’ economics. Collaborators of the W4112 multistate reproduction group have improved the ability to measure male fertility using gene biomarkers, flow cytometry, image-based deep learning algorithms, and embryonic development in vitro. These biotechnologies enhance the male fertility prediction capabilities for livestock producers to improve pregnancy success and decrease embryonic loss associated with male subfertility, which improves economic outcomes.

 Uterine-Placental-Fetal Nutritional Interactions.

• Research into fetal and placental development has revealed sex-specific effects of maternal nutrition on organ development and PAG release. Uteroplacental nutrient availability has been linked to conceptus development and survival. These findings underscore the importance of maternal environment in shaping fetal outcomes and inform strategies to improve pregnancy success and offspring viability.
• Undernutrition is common for animals maintained in a range setting, particularly during periods of drought, and during gestation this can be detrimental to offspring development. W4112 investigators are working to better understand how undernutrition during gestation impacts offspring development and are working to identify potential strategies to mitigate alterations as a result of poor maternal nutrition during gestation. Additionally, supplementation of key nutrients may influence reproductive performance. Several stations are investigating different supplements, largely omega fatty acids on reproduction. In extensive animal production systems, allowing animals ad libitum access to supplements with intake limiters may be a cost-effective method to provide nutrients and improve reproductive performance. Work is also underway to identify cell types, issues, and biological pathways that are sensitive to the maternal diet, and results will be used to develop strategic supplementation strategies to improve embryo development and pregnancy retention following periods of maternal dietary stress.
• In cattle alone, early pregnancy loss costs producers about $1.6 billion in the USA and $1.28 trillion worldwide annually. To mitigate this problem, the W4112 project has collaborated to study the mechanisms associated with early embryonic development and survival. These studies have resulted in the identification of markers for improved embryo development, maternal factors that support embryo survival and management techniques and tools to reduce pregnancy loss.
• Establishment of pregnancy, development of the placenta, and placental function are being studied in normal and compromised pregnancies. Many of the stressors in compromised ruminant pregnancies also occur in human pregnancies (hypoxia, placental insufficiency, metabolic syndrome, intrauterine growth restriction, uterine-fetal infections. The focus of the research is to better understand the normal physiological processes of pregnancy and how alterations result in suboptimal outcomes, ultimately impacting postnatal well-being and production efficiency.

Behavior and Stress.

• Environmental stressors, particularly heat stress, have been shown to impair oocyte quality and embryo yield, despite increased follicle numbers. Exposure to endocrine disruptors like atrazine has been linked to reduced dopamine synthesis in male offspring, affecting behavior and productivity. Neuroscientific studies are exploring how stress impacts reproductive efficiency, with the goal of developing strategies to mitigate these effects and improve resilience in livestock.

 Fertility, estrous synchronization and AI.

• Research into estrous synchronization and hormonal regulation has yielded significant insights into improving reproductive efficiency in livestock. Extending CIDR treatment duration has been shown to influence dominant follicular growth, estrous response, and fertility, offering potential refinements to synchronization protocols as tools for producers.
• The vaginal microbiome may play a key role in fertility and neonatal development. Several stations in W41123 are investigating the vaginal microbiome prior to artificial insemination, during early gestation, and during parturition. It appears that the vaginal microbiome may shift due to various hormone concentrations during estrus synchronization and early gestation, thus impacting the establishment of pregnancy in cattle. Further, altering the vaginal microbiome via betadine lavages near parturition increased maternal immune responses without altering neonatal microbial communities. This work will help to better understand the role of bacteria in normal reproductive processes and identify ways to positively modulate bacteria within the reproductive tract.
• Phenotypically, the SLICK1 mutation is associated with a short, slick hair coat and confers increased thermotolerance. In SLICK1 carrier animals, the JAK/STAT signaling via pSTAT3 might be reduced in hair follicles, which may affect downstream gene transcription. However, the presence of the SLICK1 allele could provide an advantage to reproductive efficiency of Holstein heifers by improving the rate of pregnancy to first service compared to non-carrier animals.
• The ISG15 protein has been validated as a pregnancy marker through its conjugation in uterine tissue. Additionally, immune cell transcriptomics offer potential for predicting infection risk and postnatal performance, paving the way for new diagnostics and therapeutic strategies.
• Innovative diagnostic tools such as the Open Cow Test (OCT) enable early pregnancy detection and management of open cows, improving herd productivity. DNA-based diagnostics and SNP markers are being developed to identify subfertile cows and predict fertility. Biomarkers for embryo mortality and immune cell transcriptomics are also being explored to enhance reproductive management and reduce economic losses due to subfertility.
• A marker for selection of in vitro derived embryos has been identified. Use of this marker to select the best embryos may improve embryo transfer rates in IVF-derived embryos in cows and possibly in humans.
• Currently members of W4112 are using sperm health-reflecting biomarkers with high throughput image-based flow cytometry (IBFC) and artificial intelligence/deep learning analysis as a method to create bioimage algorithms that can detect sperm acrosome health status (reflected by lectin PNA-Cy5) on brightfield images. This could allow for selection of the most viable sperm to fertilize eggs and could aid in vitro fertilization or artificial insemination to increase fertility rates.

Education

• Education and technology transfer efforts have demonstrated the value of hands-on training in promoting the adoption of new reproductive technologies. Involvement of undergraduate and graduate students in research projects has fostered knowledge dissemination and capacity building. These initiatives support the long-term integration of scientific advancements into livestock production systems. Hands-on reproductive training significantly improves rancher skills and yields \$1,000–\$5,000 ROI per ranch annually.

 

Objectives

1. Elucidate cellular, physiological, endocrine, and behavioral mechanisms regulating gamete development and quality for translational reproductive biotechnologies.
   
2. Determine how reproductive and animal management practices and environmental stressors influence follicle recruitment, ovulation, corpus luteum function, and pregnancy, and develop genomic and phenotype-informed strategies to improve reproductive efficiency and longevity.
   
3. Elucidate maternal and paternal mechanisms regulating embryo development, pregnancy establishment, and maintenance through integrated investigation of fertility-associated genomic markers, immune regulation, fetal programming, and conceptus–uterine signaling, supported by advanced multi-omic, computational, and machine-learning approaches.
   

Methods

W5112 collaborators share a common interest in developing and validating methods to optimize reproductive efficiency in domestic ruminants, but differ in expertise, laboratory infrastructure, availability of research animals, and emphasis on basic versus applied research. This diversity in capabilities provides a unique opportunity to integrate mechanistic discovery with applied validation across multiple production systems. Through coordinated experimental design, sharing of biological samples, harmonization of outcome measures, and joint data analysis, the group will collectively generate knowledge that cannot be achieved by individual stations working independently. Outlined below are the major research approaches that will be employed to address each objective during the proposed project period. Collaborative participation among stations is explicitly incorporated into each research area to ensure coordinated planning and multistate synthesis of findings.

Mechanisms of Gamete Development, Ovulation, and Cyclicity (Objective 1)

Research addressing Objective 1 will focus on elucidating cellular, endocrine, and neuroendocrine mechanisms regulating gamete development, ovulation, and reproductive behavior using complementary in vivo, ex vivo, and in vitro models in cattle and sheep. Investigations into the endocrine events underlying the pre-ovulatory surge will continue, with emphasis on identifying genomic and non-genomic pathways through which estradiol and other signals regulate LH secretion and gonadotrope function. Molecular approaches, including cell-specific transcriptomics, fluorescence-based cell sorting, and single-cell or single-nuclei RNA sequencing, will be used to characterize pituitary and ovarian cell populations involved in ovulatory control. Parallel studies will evaluate ovarian follicle development and steroidogenesis through combined in vivo endocrine manipulation and in vitro follicle and ovarian tissue culture systems, allowing real-time assessment of ovarian responses to FSH, estradiol, and other regulatory factors. Whole-genome sequencing and targeted genotyping will be conducted in animals with well-characterized reproductive phenotypes (e.g., altered puberty attainment, androgen excess, anovulation) to identify genetic variants associated with reproductive longevity and gamete quality. These genomic datasets will be shared across participating stations for integrative analyses linking genotype to endocrine and cellular phenotypes. Collectively, these approaches allow mechanistic discoveries made at one station to be functionally validated at others using shared models, samples, and analytical pipelines.

Effects of Management, Environment, and Stress on Ovarian Function and Pregnancy (Objective 2)

Objective 2 will be addressed using coordinated field-based and controlled experimental studies examining how management practices and environmental stressors influence follicle recruitment, ovulation, corpus luteum (CL) function, and pregnancy outcomes. Participating stations will conduct studies evaluating nutritional status, metabolic stress, photoperiod, thermal stress, and reproductive management strategies (e.g., estrus synchronization, progesterone and progestin use) across diverse production environments.

Common outcome measures, including ovarian dynamics assessed by ultrasonography, endocrine profiles, uterine and luteal blood flow, microbiome composition, and pregnancy diagnostics, will be standardized through joint planning to enable pooling and cross-site comparison of data. Stations with large animal populations will generate biological samples (blood, reproductive tissues, microbial samples, as well as genotype data) that will be shared with collaborators for specialized analyses, including molecular, microbial, and endocrine assessments. Stress mitigation strategies, such as targeted antioxidant or nutritional interventions, will be evaluated for their effects on CL function and early pregnancy maintenance, integrating applied trials with mechanistic follow-up studies. This coordinated framework enables robust evaluation of management strategies across multiple climatic and production systems.

Embryo Development, Pregnancy Establishment, and Fetal Programming (Objectives 2 and 3)

Research addressing Objectives 2 and 3 will focus on maternal and paternal mechanisms regulating early embryo development, implantation, placentation, and fetal growth. In vivo pregnancy models in cattle and sheep will be used to examine conceptus–uterine signaling, immune interactions, placental vascular development, and endocrine regulation of pregnancy maintenance. Assisted reproductive technologies, embryo manipulation, and pregnancy diagnostics will be integrated with molecular analyses to identify determinants of embryonic survival and pregnancy loss. Fetal programming studies will assess how maternal environment, nutrition, stress, and microbiome composition influence placental function, fetal development, and postnatal outcomes. These studies will employ longitudinal designs that follow offspring across gestation and into postnatal life, with coordinated sampling of maternal, placental, and fetal tissues. Epigenomic, transcriptomic, immune, and metabolic datasets generated across stations will be pooled for multistate analyses to identify conserved mechanisms underlying pregnancy success and developmental programming. Paternal contributions will be evaluated through analyses of sperm quality, microbiome composition, and genomic or epigenomic predictors of fertility, integrating datasets across stations to improve predictive accuracy.

 Male Reproduction and Sire Fertility (Objectives 1 and 2)

Research supporting Objectives 1 and 2 will focus on identifying cellular, endocrine, and behavioral determinants of sire fertility that influence reproductive efficiency at the herd level. Studies will evaluate sperm production, sperm function, and male reproductive behavior using semen quality assessments, functional sperm assays, endocrine profiling, and behavioral analyses. Advanced multi-omics approaches, including proteomics, metabolomics, lipidomics, genomics, and epigenomics, will be used to identify biomarkers predictive of male fertility, with functional validation through imaging-based sperm phenotyping, flow cytometry, and in vitro fertilization or capacitation systems. Participating stations will coordinate the use of shared semen samples, standardized fertility metrics, and harmonized analytical pipelines, enabling integration of datasets across studies and production systems to improve identification and management of fertile sires.

Disease and Stress Influences on Reproductive Function (Objectives 1 and 3)

Studies investigating the link between infection and ovarian dysfunction will be conducted using approaches that examine how infectious or inflammatory processes alter ovarian signaling pathways, estrogen production, and fertility. Complementary research will examine how environmental exposures, including toxicants associated with wildfire and industrial chemicals, disrupt ovarian function through molecular, cellular, and metabolic mechanisms. In addition, studies evaluating stress-induced suppression of reproductive endocrine function will investigate neural and hormonal pathways that impair gonadotropin secretion under adverse conditions. Data and biological samples generated through these studies will be shared among collaborating stations and integrated with reproductive outcome measures to evaluate how infection, inflammation, and stress directly impair reproductive function, while remaining distinct from studies of male fertility or non-immune nutritional programming.

Multistate Coordination, Data Sharing, and Synthesis

Coordination among participating stations is maintained through annual technical committee meetings, during which members review progress, align protocols, identify shared outcome measures, and plan new collaborative studies. Ongoing communication between meetings facilitates the exchange of biological samples, harmonization of methodologies, and joint interpretation of results. Data generated across objectives are shared among participating scientists and analyzed using coordinated statistical approaches, enabling multistate synthesis of findings. Results are disseminated through joint peer-reviewed publications, extension programming, and stakeholder engagement activities, ensuring that outcomes represent a collective, integrated research effort with broad scientific and practical impact.

Measurement of Progress and Results

Outputs

• The project will generate coordinated multistate research datasets from planned activities, including reproductive phenotypes, physiological and endocrine measurements, and genomic, epigenomic, transcriptomic, proteomic, metabolomic, microbiome, and environmental data.
• The project will produce analyzed data and information describing cellular, physiological, endocrine, and molecular mechanisms regulating gamete development, ovulation, reproductive behavior, embryo development, placentation, and pregnancy establishment.
• The project will develop and refine experimental models and assays to assess ovarian, uterine, placental, fetal, and sperm function under diverse management, environmental, and stress conditions.
• Generate biological and physical materials, including reproductive tissues, oocytes, embryos, placental samples, semen samples, and associated molecular reagents, for use in coordinated analyses.
• Generate integrated data enabling identification of candidate biological indicators, including biomarkers and genetic variants associated with fertility, embryo survival, pregnancy maintenance, reproductive longevity, and offspring performance.
• The project will develop harmonized protocols, standardized outcome measures, and analytical pipelines to support coordinated data collection and analysis across participating stations.
• The project will curate shared research resources, including datasets, biological materials, and protocols, to support coordinated analyses and replication across systems.
• The project will produce research-derived information products, including peer-reviewed publications, scientific presentations, extension-oriented summaries, and training-related outputs generated by graduate students, postdoctoral researchers, and early-career scientists.

Outcomes or Projected Impacts

• Improved reproductive efficiency in domestic ruminants is expected to generate economic impacts for U.S. livestock producers by reducing fertility-related losses, which are currently estimated at approximately $4.7 billion annually in beef cattle and contribute to reduced productivity in the U.S. dairy industry (IDFA, 2025), an industry that contributes more than $750 billion to the national economy (Lamb et al., 2008).
• Adoption of science-based reproductive knowledge generated through W5112 is expected to reduce early embryonic loss, pregnancy failure, and repeat breeding, leading to shorter reproductive intervals and increased lifetime productivity of breeding animals in beef, dairy, and sheep production systems.
• Economic impacts are anticipated through reduced costs associated with infertility and pregnancy loss, improved efficiency of natural service and assisted reproductive technologies, and increased consistency of pregnancy success at regional and national scales.
• Improved understanding and management of reproductive biology are expected to enhance producer decision-making and herd-level reproductive performance, supporting greater production efficiency and long-term sustainability of livestock operations.
• Increased resilience of livestock systems is anticipated through improved management of fertility under environmental and physiological stressors, including heat stress, nutritional insufficiency, endocrine-disrupting compounds, infectious and inflammatory challenges, and other environmental toxic exposures, reducing stress-related reproductive losses under variable production conditions.
• Social impacts include strengthened rural agricultural enterprises and enhanced capacity of producers, veterinarians, and industry professionals to implement evidence-based reproductive management practices.
• Workforce impacts include preparation of a highly trained agricultural and scientific workforce, with graduate students, postdoctoral scholars, and early-career scientists gaining expertise in reproductive biology, genomics, systems physiology, and data-driven analytical approaches relevant to livestock production systems.
• Collectively, these impacts support the long-term competitiveness and sustainability of U.S. livestock industries by improving reproductive performance, reducing economic risk associated with infertility, and strengthening the scientific and technical workforce supporting animal agriculture.

Milestones

(2026):Project initiation and start-up (Objectives 1–3). Initiate project start-up activities during the initial partial project year. Establish multistate communication mechanisms, confirm participating stations and personnel, and begin aligning experimental approaches, reproductive outcome measures, and data standards encompassing gamete quality, ovarian and luteal function, pregnancy establishment, and sire fertility. Engage graduate students, postdoctoral trainees, and early-career scientists in preliminary multistate planning activities.

(2027):Coordination, data generation, and first formal review (Objectives 1–3). Initiate coordinated multistate research activities addressing all objectives. Generate multistate datasets addressing cellular, physiological, endocrine, and genomic mechanisms regulating reproduction in domestic ruminants. Identify candidate biological indicators and management factors associated with reproductive efficiency and pregnancy success. Conduct the first formal W5112 technical committee meeting to align protocols, document progress, and identify collaborative analyses. Communicate early progress through coordinated presentations at national scientific meetings, including the American Society of Animal Science, Society for the Study of Reproduction, American Dairy Science Association, and the International Embryo Technology Society.

(2028):Continued data generation and interim synthesis (Objectives 1–3). Continue coordinated multistate data generation across objectives and production systems. Conduct interim cross-state analyses to evaluate consistency of findings across species, environments, and management conditions. Hold the annual W5112 technical committee meeting to review progress and refine collaborative activities. Communicate interim findings through national scientific meetings and coordinated project presentations.

(2029):Integration, validation, and mid-project synthesis (Objectives 1–3). Validate selected biological indicators, diagnostic approaches, and management strategies across multiple states and production conditions. Deliver a coordinated W5112 symposium at the Midwest Animal Science Meeting during the project year. Conduct the annual technical committee meeting to synthesize findings across objectives and guide translational activities.

(2030):Translation and stakeholder engagement (Objectives 1–3). Refine and assess predictive tools, diagnostics, and management recommendations developed through integrated W5112 research. Evaluate effects on reproductive performance indicators (e.g., pregnancy rates, pregnancy loss, calving or lambing intervals) and estimate associated economic implications under representative production scenarios. Disseminate findings through peer-reviewed publications, extension materials, and producer-focused meetings. Conduct the annual technical committee meeting to assess progress and guide final synthesis.

(2031):Final synthesis, reporting, and future planning (Objectives 1–3). Complete multistate synthesis of results across objectives, species, and production systems. Communicate final project findings through national scientific venues (ASAS, ADSA, SSR, IETS) and producer-focused forums (DCRC, ARSBC). Conduct the final W5112 technical committee meeting. Prepare final project reports documenting scientific accomplishments, stakeholder relevance, and measurable outcomes, and develop coordinated plans for future multistate renewal and competitively funded research efforts.

Projected Participation

View Appendix E: Participation

Outreach Plan

Results from the W5112 project will be disseminated through coordinated extension, outreach, and stakeholder engagement activities designed to ensure accessibility and practical value to livestock producers, industry professionals, and allied stakeholders. Project findings will be communicated through peer-reviewed scientific publications, extension publications, and non-refereed but peer-reviewed outreach materials developed collaboratively by participating stations with extension appointments and strong producer-facing programs.

Extension outputs will include fact sheets, applied research summaries, and decision-support materials addressing reproductive management, fertility indicators, and strategies to improve pregnancy success under diverse production conditions. Participating stations will integrate W5112 findings into field days, producer workshops, extension meetings, and regional symposia, including events focused on beef, dairy, and sheep systems. These activities will leverage existing extension networks and websites at South Dakota State University, Mississippi State University, Florida, Missouri, Montana, Nebraska and other stations with active outreach programs, ensuring broad geographic reach and ease of access.

Producer engagement will be facilitated through established producer and extension networks, including cattlemen’s associations, dairy and sheep producer groups, and state and regional extension advisory committees. Results will be shared through in-person events and online platforms to maximize accessibility, including recorded presentations and digital extension materials. Outreach efforts will prioritize clarity, practicality, and relevance to producers operating under variable environmental and economic conditions, including small and mid-scale operations and underserved or rural communities.

W5112 will actively engage industry partners, including artificial insemination companies, genetics organizations, nutrition companies, and biotechnology stakeholders, to facilitate bidirectional exchange of information. These partnerships will support translation of research findings into applied tools, fertility evaluation strategies, and management recommendations, while ensuring industry needs inform ongoing research priorities.

Organization/Governance

The W5112 Regional Research Project is organized as a technical committee composed of representatives from participating stations and is governed by an Executive Committee consisting of a Chair, Secretary, and Member-at-Large. The Member-at-Large is elected annually by the technical committee and serves a three-year rotating term, progressing to Secretary in year two and Chair in year three, ensuring continuity of leadership. The Administrative Advisor, appointed by the Western Directors, serves on the Executive Committee and provides guidance on administrative oversight and reporting requirements. The Executive Committee is responsible for coordinating annual meetings, facilitating communication among members, documenting progress, and ensuring alignment of activities with approved objectives. Ad hoc working groups may be formed as needed to coordinate specific research activities or symposia. Mentorship and training are incorporated through the participation of graduate students, postdoctoral scholars, and early-career scientists in technical committee meetings and collaborative research activities, with senior members providing guidance through shared project leadership and collaborative research efforts.

Literature Cited

• Carlin, J. D. 2025. Dairy delivers. International Dairy Foods Association (IDFA). https://www.idfa.org/news/dairydelivers
• International Dairy Foods Association (IDFA). 2025. U.S. dairy industry’s economic impact totals $753 billion. IDFA news release. Accessed 2025. https://www.idfa.org/news/u-s-dairy-industrys-economic-impact-totals-753-billion
• Knight, R. 2025. Cattle and beef—sector at a glance. Economic Research Service, U.S. Department of Agriculture. https://www.ers.usda.gov/topics/animal-products/cattle-beef/sector-at-a-glance
• Lamb, G. C., C. Daheln, and M. Maddox. 2008. What is the economic impact of infertility in beef cattle? The BeefSite. https://www.thebeefsite.com/articles/1698
• National Cattlemen’s Beef Association (NCBA). 2025. Beef industry review and consumer insights: February 2025 edition. Beef Checkoff Program. https://www.beefresearch.org
• Shiflett, J. S. 2008. Sheep industry economic impact analysis. American Sheep Industry Association (ASI). https://www.sheepusa.org
• S. Department of Agriculture (USDA). 2025. Cattle—cows, beef: inventory (head). USDA National Agricultural Statistics Service. Accessed 2025. https://app.usda-reports.penguinlabs.net/
• S. Department of Agriculture, Economic Research Service (USDA-ERS). 2025. U.S. cattle inventory and beef production trends. Chart gallery, Chart ID 82244. Accessed 2025. https://www.ers.usda.gov/data-products/chart-gallery/chart-detail?chartId=82244

Attachments

Land Grant Participating States/Institutions

Non Land Grant Participating States/Institutions