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

Administrative Advisor(s):

NIFA Reps:

Non-Technical Summary

Bovine respiratory disease (BRD) is the leading cause of treatment, death loss, and compromised growth U.S. beef and dairy cattle production, and drives a large portion of antimicrobial use. New types of production systems (e.g., beef-on-dairy calves) and the increasing recognition of late-feeding period pneumonia and cardiopulmonary disorders are changing how and when BRD occurs. Because these conditions arise from complex interactions among pathogens, the animal’s immune system, management practices, and environment, improved, systems-based solutions are needed. The overall goal of this project is to reduce the incidence, severity, and economic impact of respiratory disease in livestock. We aim to (1) define how host, pathogen, and environmental factors interact to cause respiratory and associated cardiopulmonary disease; (2) develop and validate diagnostics and surveillance tools suitable for research and field use; (3) evaluate vaccines, therapeutics, nutrition, and management strategies that sustainably prevent or mitigate disease; (4) quantify economic and system-level drivers of respiratory disease and model the impacts of alternative control strategies; and (5) accelerate translation of these findings into practice through coordinated outreach. The primary audiences include cattle producers, veterinarians, diagnostic laboratories, industry partners, and policymakers. They will benefit from more accurate diagnostic tools, clearer risk assessment, improved prevention programs, and better estimates of economic return on interventions. Multi-state collaborative research teams will integrate field studies, laboratory experiments, genetic and genomic analyses, and economic modeling. Results will be communicated via producer education, veterinary continuing education, webinars, and the Bovine Respiratory Disease Symposium, enabling timely adoption of evidence-based practices.

Statement of Issues and Justification

Bovine respiratory disease (BRD) continues to be the most significant cause of morbidity, mortality, and economic loss in the U.S. cattle industry [1-3]. Affecting both beef and dairy cattle across all production stages, BRD results in substantial animal welfare concerns and inefficiencies throughout production cycles [1,2]. Stakeholders across the beef, dairy, and allied industries, which includes veterinarians, producers, consultants, and industry partners, continue to identify BRD as a top research and extension priority due to its complex etiology, persistent economic burden, and the continued absence of effective, long-term control strategies [3].

Despite decades of research, BRD remains the leading cause of feedlot morbidity, preweaning calf mortality, and antimicrobial use in cattle [3,4]. Recent industry data also point to emerging challenges associated with respiratory health in evolving production systems, such as beef-on-dairy crossbred calves, which may exhibit unique disease susceptibilities and performance outcomes [3,5]. These production shifts, coupled with changes in management and marketing tactics, highlight the urgent need for renewed collaborative investigation that spans the full range of cattle production systems, from cow-calf and calf ranch operations to stocker, feedlot, and lactating dairy systems.

While the exact amount remains unknown, the annual economic impact of BRD likely exceeds hundreds of millions of dollars (USD) per year in the United States when accounting for mortality, treatment costs, and performance losses [6-8]. However, this figure underestimates the full burden of the disease, as current economic data are outdated, inconsistent, or incomplete across production sectors. Moreover, mortality loss has never been more expensive, yet comprehensive, system-specific economic assessments are scarce. Stakeholders have emphasized the critical need for new economic surveys and data-driven modeling to accurately quantify both direct and indirect impacts of BRD and related cardiopulmonary conditions. These assessments would support producers, consultants, and policymakers in implementing evidence-based, cost-effective strategies that improve animal health and resource efficiency.

Beyond direct financial losses, BRD represents a major constraint to sustainable beef and dairy production, influencing animal welfare, environmental sustainability, and consumer perception of industry practices. Failure to advance our understanding of BRD pathogenesis, epidemiology, and control strategies perpetuate systematic reliance on antimicrobials, increase production inefficiencies, and heighten production system vulnerabilities to emerging or underreported respiratory and cardiopulmonary syndromes. Without the proposed multidisciplinary efforts, the U.S. livestock industry will remain at risk from evolving disease dynamics that continue to influence respiratory disease outcomes.

While BRD remains the central focus, there is growing recognition that respiratory disease exists within a broader cardiopulmonary and systemic context. Emerging evidence links pulmonary disease to gastrointestinal health and systemic inflammation, suggesting that digestive tract integrity and microbial balance can significantly influence respiratory resilience [2,9,10]. Additionally, specific respiratory conditions such as bronchopneumonia, acute interstitial pneumonia, and mixed broncho-interstitial pneumonia contribute substantially to respiratory-related mortality and require refined diagnostic and pathologic characterization for improved prognostic, diagnostic, and therapeutic developments [11]. By broadening the project’s scope to include these cardiopulmonary and interconnected conditions, we would better address the multifactorial nature of respiratory health and expand our capacity to develop integrated diagnostic and management preventive solutions.

Improved surveillance and longitudinal data collection are critical for understanding the changing epidemiology of respiratory disease. There is limited information on disease prevalence and economic impact in the stocker, backgrounding, and beef-on-dairy sectors, in addition to an insufficient approach to standardization in diagnostic reporting across research laboratories. Enhanced surveillance, coupled with advanced data integration and modeling approaches, will facilitate earlier detection of emerging pathogens and quantify how production system attributes contribute to respiratory disease dynamics. This will allow improved identification of critical leverage points where targeted interventions, such as improved vaccination strategies, management changes, or genetic selection, may yield the most significant impact on respiratory disease control and resource efficiency.

The proposed research is built upon the proven capacity and expertise of NC1192 member stations, which collectively possess the infrastructure, datasets, and interdisciplinary expertise required to address BRD and related diseases (e.g., congestive heart failure, endocarditis, liver abscessation, etc.) from molecular to systems-based levels. Advances in genomics, metagenomics, transcriptomics, and systems biology now enable integrated exploration of the host–pathogen–environment relationship and multivariable risk factors that confer respiratory disease resistance or tolerance. Ongoing efforts have identified gene expression markers linked to BRD resistance, characterized virulence mechanisms of key pathogens, and developed improved diagnostic and vaccination tools [12-16]. Moreover, the multistate structure of NC1192 offers unique advantages as it brings together complementary expertise in epidemiology, microbiology, immunology, economics, nutrition, genetics, and animal husbandry while representing the multitude of production environments across the U.S. Coordinated collaboration allows standardized protocols, larger sample sizes, and broader applicability of research findings. Shared access to diagnostic tools, pathogen isolates, and multi-institutional datasets would accelerate discovery, validation, and translation into field-relevant outcomes. Furthermore, active partnerships with national organizations such as the American Association of Bovine Practitioners (AABP), the Academy of Veterinary Consultants (AVC), and industry collaborators ensure that emerging knowledge rapidly reaches stakeholders who can apply it in practice.

Completion of the proposed work will yield measurable scientific, economic, and societal benefits, including:

• Enhanced understanding of respiratory and associated disease etiologies;
• Improved diagnostic, surveillance, and control strategies against respiratory disease;
• Quantified economic impact and system-based solutions for respiratory disease;
• Expanded knowledge transfer and capacity building.

Related, Current and Previous Work

Members of NC1192 have identified several knowledge gaps related to the project objectives and have worked collaboratively during the last five years to address these gaps, generating the following research outcomes: 1) Molecular epidemiological assessment of beef cattle management systems examined how markets and vaccination influence bovine respiratory disease (BRD) risk through collaborative research between TX and MSU. Using multi-omics and transcriptomic approaches, differential gene expression profiles were characterized across production stages, revealing significant immunologic differences associated with preweaning vaccination and marketing strategies. These data provided the foundation for predictive models linking management decisions to host immune regulation and subsequent BRD development. 2) A longitudinal study led by TX and MSU evaluated the influence of tulathromycin metaphylaxis on whole blood transcriptomes in high-risk stocker cattle. Results demonstrated consistent inflammatory gene expression signatures in BRD-affected cattle regardless of antimicrobial administration, suggesting distinct molecular pathways associated with disease susceptibility and therapeutic response. 3) Targeted transcriptome analysis performed by TN and AU investigated immune modulation in cattle persistently infected with bovine viral diarrhea virus (BVDV). Results showed chronic upregulation of interferon-gamma and related inflammatory genes, indicating persistent immune activation and dysregulation in long-term carriers. 4) WSU and TX conducted large-scale genomic profiling to identify loci associated with BRD resistance. Over 20,000 calves from multiple states were genotyped and analyzed for disease-associated loci, resulting in identification of candidate genes and pathways related to innate and adaptive immunity, and establishing one of the largest BRD genomic datasets to date. 5) AU, MSU, and UGA developed an experimental infection model of H5N1 in Jersey dairy cattle to evaluate susceptibility, pathogenesis, and tissue tropism. Results demonstrated mammary gland tropism and confirmed Jersey cattle as a valid model for future vaccine and antiviral testing. 6) TN and WSU evaluated respiratory disease outcomes in calves postweaning following in-utero BVDV infection. Preliminary results demonstrated long-term dysregulation of proinflammatory cytokine production following subsequent Mannheimia haemolytica challenge, indicating prolonged immune alteration beyond the neonatal period. 7) MSU, TX, and MN collaborated on a study assessing the effects of commingling and transport on bovine respiratory coronavirus shedding in dairy calves. Early findings showed differential viral shedding and stress-related cytokine expression between groups, providing insight into disease dynamics following transport and mixing. 8) UGA and TX conducted transcriptomic profiling of lymphoid tissue from calves vaccinated and challenged with BVDV and BHV1, with or without trace mineral supplementation. Distinct co-expression modules were associated with vaccination and mineral treatment, identifying key pathways involved in T-cell activation, antigen presentation, and complement regulation. 9) MSU and TX performed an integrated transcriptomic and mineral analysis of stocker cattle fed different trace mineral formulations. Combined serum, liver, and gene expression data demonstrated that amino acid–complexed minerals modulated pathways involved in carbohydrate metabolism and adaptive immunity, supporting refinement of nutritional interventions for BRD prevention. 10) KS and SD conducted an intranasal modified-live trivalent BRSV vaccine efficacy trial in neonatal calves, demonstrating reduced lung lesions, enhanced mucosal immunity, and improved growth performance following challenge. 11) KSU led a randomized field trial comparing three macrolide antibiotics for treatment of BRD in nearly 1,000 feedlot steers. No significant differences were found in retreatment, removal, or mortality rates, suggesting comparable effectiveness among macrolide products in first-line therapy. 12) MSU and UGA investigated the impact of intranasal copper, zinc, and magnesium administration on the respiratory microbiome of transported calves. Metagenomic sequencing demonstrated modulation of bacterial community structures and abundance following mineral treatment, indicating potential for topical immunomodulation strategies. 13) AU, MSU, and UGA extended this work by experimentally infecting calves treated intranasally with the same mineral formulation prior to BHV1 challenge. Treated calves exhibited altered microbial composition and immune activation profiles, supporting the role of intranasal minerals in enhancing respiratory defense. 14) TX, KS, and MSU collaborated to assess the impacts of preweaning vaccination and marketing decisions on BRD morbidity, mortality, and inflammatory response during subsequent production phases. Early results indicated that preweaning vaccination did not impair performance and that marketing through auction systems was associated with increased acute-phase protein response. 15) KS and TX evaluated performance impacts of different castration methods in feedlot cattle, providing data to refine animal welfare and handling recommendations in collaboration with industry partners. 16) KS, TX, and MSU initiated an economic modeling study to quantify the costs associated with late-day pulmonary disease (LDPD) in feedlot cattle. The ongoing work integrates biological data, intervention costs, and outcome probabilities to support cost-benefit analyses of control strategies. 17) TX and MSU continued development of molecular tools to monitor antimicrobial resistance (AMR) in Mannheimia haemolytica using passive environmental sampling methods. Rope and water sampling demonstrated promise as alternatives to nasopharyngeal swabs, potentially enabling large-scale AMR surveillance with reduced animal handling. 18) MSU and TX analyzed the nasopharyngeal microbiome and resistome of metaphylaxis-treated cattle using 16S and shotgun sequencing. Findings characterized shifts in microbial community structure and resistance gene prevalence, informing antimicrobial stewardship in feedlot systems. 19) KS, SD, and the PAC Group investigated handling intensity effects at processing on inflammatory and immune stress markers in feedlot calves. Results confirmed that aggressive handling elevated stress and inflammatory responses, emphasizing the importance of low-stress management practices for BRD mitigation. 20) A multi-institutional collaboration among TX, KS, and MSU continued to develop predictive molecular signatures of BRD susceptibility using integrated genomics and transcriptomics. These datasets are being leveraged to create machine learning models for early disease detection and individualized risk assessment. 21) NC1192 members organized and hosted the 4th Bovine Respiratory Disease Symposium in August 2024 in partnership with the Academy of Veterinary Consultants. Over 300 veterinarians, scientists, and industry representatives attended. Proceedings were published in Animal Health Research Reviews, and the event facilitated new collaborations for the next project cycle. 22) KS, SD, and collaborating industry partners delivered extensive outreach and producer education through 34 extension meetings, multiple training programs, and publication of 15 popular press articles focused on BRD management, cattle welfare, and antimicrobial stewardship.

Objectives

1. Elucidate host-pathogen-environment interactions underlying respiratory disease and associated disorders in livestock
   
2. Develop and validate diagnostic and surveillance methodologies for respiratory disease in livestock
   
3. Develop and assess sustainable management, therapeutic, and preventative interventions for respiratory disease in livestock
   
4. Characterize and model system-level, economic, and societal drivers of respiratory disease in livestock production
   
5. Translate collaborations and knowledge of respiratory disease research into practical applications
   

Methods

Objective 1: Elucidate host-pathogen-environment interactions underlying respiratory disease and associated disorders in livestock

Historically BRD has been recognized as disproportionately affecting feedlot cattle in the first 45 days after arrival. Recently, BRD in cattle that have been on feed for longer than 45 days has increasingly been described. This is a serious problem because cattle on feed greater than 45 days are relatively more valuable to the feedlot, as more time and financial resources have been invested in them. Bronchopneumonia (BP) is the pathological lesion classically attributed to a diagnosis of BRD in feedlot cattle, while acute interstitial pneumonia (AIP) is recognized as a different syndrome, occurring later in the feeding period. Recently, bronchopneumonia with an interstitial component (BIP) was described to affect a substantial proportion of cattle dying with a diagnosis of BRD. Importantly, BIP was significantly more common in cattle dying at greater than 150 days on feed. Little is known regarding the factors that cause cattle to develop BIP, though the prevalence of a BIP diagnosis increased with increasing number of treatments for BRD, suggesting BIP could result from chronic, unresolved pulmonary inflammation. Work led by researchers in Kansas (KS), Texas (TX), Colorado (CO), and Mississippi (MSU) will evaluate the distribution of histopathologic lung diagnoses in feedlot cattle dying at greater than 45 days after arrival, in order to confirm the pathologic lesion characterizing late-day pulmonary mortality cases. Cattle dying at multiple feedlots in TX and KS will be subjected to standardized gross necropsy, with lung tissue from two sites (cranial lung and caudal lung) collected into formalin for histopathologic evaluation. Histopathologic lung lesions will be evaluated and described by board-certified veterinary pathologists. Rates of histopathologic diagnosis of BP, AIP, and BIP will be determined. In a subset of feedlots, the relationship between histopathologic diagnosis and antemortem characteristics of the animal (sex, days on feed at death, number of treatments prior to death, time of year at death) and lot (source, distance transported, average weight at arrival, time of year at arrival) will be evaluated to confirm whether relationships identified in previous research based on gross (macroscopic) lung diagnosis are maintained when the more accurate histopathologic diagnosis is incorporated into the assessment.

Research involving the targeted transcriptome analysis of cattle persistently infected (PI) with bovine viral diarrhea virus (BVDV) serves as a collaboration between Tennessee (TN) and Alabama (AU). The purpose of this study was to use transcriptome analysis to investigate the long-term immune status of adult PI cattle and offer insight into the potential mechanistic establishment of persistent BVDV infection. Transcriptome changes indicated chronic upregulation of interferon-gamma (IFNG) with an unexpected expression of related genes, indicating a chronic pro-inflammatory state in PI cattle compared to healthy controls.

Respiratory disease research is being conducted in calves post-weaning exposed to an in-utero BVDV infection, as a collaboration between TN, WSU, and SD. The purpose of this study is to evaluate the long-term immunologic impacts of in utero BVDV infection in weaned calves. Preliminarily, calves infected with BVDV at 200 days of gestation demonstrate decreased concentrations of pro-inflammatory cytokines when infected with Mannheimia hemolytica compared to controls. Data supports evidence of prolonged dysregulation of the immune response in calves transiently infected with BVDV, past the neonatal phase.

Collaboration between WSU and TX is ongoing in effort to identify pathogen profiles and trait loci associated with enhanced resistance to respiratory disease. Bacteriology and virology are being used to identify pathogen profiles from mid-nasal and deep pharyngeal swabs and Illumina BovineHD BeadChips will be used for genotyping. Genome-wide association results will be compared with previous results in pre-weaned dairy calves in California and New Mexico. Additionally, eight other dairies have been evaluated for BRD and genotyped and have been analyzed. In Washington and Idaho, approximately 4500 pre-weaned calves were genotyped and about 5200 post-weaned calves were genotyped and analyzed for loci associated with BRD. In Georgia, over 15,000 calves were genotyped and analyzed for loci associated with BRD, with additional gene set enrichment analyses to be conducted.

Research between AU, UGA, and MSU is currently being conducted to explore experimental infection and viral pathogenesis of H5N1 in jersey cattle. In recent years, highly pathogenic avian influenza H5N1 viruses have crossed the species barrier into multiple species, including dairy cattle, causing a significant decrease in milk production and rapid spread across multiple U.S. states in 2024. Previous studies have demonstrated that Holstein cows are susceptible to H5N1 infection. To investigate whether Jersey cows are susceptible to H5N1 infection and their potential as an experimental model, lactating Jersey cattle are to be clinically and molecularly evaluated following experimental inoculation both intranasally and intramammarily with a human H5N1 influenza virus.

Researchers from California (UCD) in partnership with Atlantic Tech University in Ireland aim to continue work on defining environmental risk factors and their impact on risk of respiratory disease. This work will provide novel insights into how short-term weather patterns influence respiratory disease development, supporting the development of region-specific prevention strategies

Research conducted by researchers at MSU and TX aims to develop a primary bovine bronchial epithelial cell culture system and use it as an in vitro platform to study infection dynamics of bovine respiratory syncytial virus (BRSV). The goal is to establish a physiologically relevant, reproducible model that supports future studies of viral pathogenesis and host response. The project consists of two main objectives: 1) establish and characterize primary bovine bronchial epithelial cell cultures and 2) assess the utility of the cell culture model as a proxy for in vivo BRSV infection.

 

Objective 2: Develop and validate diagnostic and surveillance methodologies for respiratory disease in livestock

Investigators between TN, KS, and TX are in the early stages of building an experimental design and proposal intended to determine the patterns of pathobiont transmission among beef cows and their calves. In this study we hope to establish a connection between dams that carry common BRD pathogens as part of their nasal commensal community and the potential timeframe of transmission to their calves and its subsequent impact on the calves health in the pre- and post-weaning timeframe. Researchers are currently collecting preliminary carriance data among cows and calves housed at one of TN’s research and education center farms.

Researchers at KS, TX, CSU, and MSU are utilizing digital histopathological images from late-day feedlot mortality cases to develop and optimize a supervised machine learning platform to determine the predictive capabilities of a computer vision modeling system. This effort would allow for automated screening of digitalized lung histopathology sections to expedite the diagnostic and classification capabilities of BRD diagnostics.

Collaboration between TN and WSU is ongoing to evaluate the long-term immunologic impacts of in-utero BVDV infection in weaned calves (as seen in Objective 1). Calves infected with BVDV at 200 days of gestation demonstrate decreased trends of pro-inflammatory cytokines when infected with Mannheimia hemolytica, compared to non-infected calves. Data supports evidence of prolonged dysregulation of the immune response in calves transiently infected with BVDV, past the neonatal phase. These researchers are currently developing a saliva-based Mannheimia hemolytica antibody titer using samples from previous work.

 

Objective 3: Develop and assess sustainable management, therapeutic, and preventative interventions for respiratory disease in livestock

Research by MSU and TX has shown that expression of the gene encoding arachidonate 15-lipoxygenase (ALOX15) is consistently upregulated in cattle in high risk populations that resist BRD. ALOX15 induces production of lipoxins, a family of specific pro-resolving mediators (SPM), which modulate inflammatory responses in many lung disorders. These findings suggest that lipoxins and other SPMs may modulate respiratory inflammation in cattle; therapies that induce cattle to increase SPM production could lead to less BRD in at-risk populations. Researchers from MS and TX aim to evaluate the transfection of cells with mRNA expressing ALOX15, or mRNA expressing a gene activating complex inducing expression of the endogenous gene for ALOX15, increases expression of SPMs in bovine airway cells. Primary bovine airway epithelial cells will be transfected with mRNA encoding either bovine ALOX15, or ALOX15 gene activating complex using previously developed methods. At 2, 6, 12, and 24 h post treatment, supernatants and cell lysates will be collected and snap frozen for measurement of bovine A-series lipoxins and D-series resolvins by mass spectroscopy. These researchers will also test the effect of mRNA treatment by evaluating transcriptomes of transfected cells for differential expression of SPM-related genes.

Investigators at TN and WSU are currently performing a randomized controlled trial under field conditions to evaluate the effect of two commercially available Mannheimia haemolytica vaccines in pre-weaned Holstein heifers. Utilizing serial clinical respiratory scoring and thoracic ultrasound scoring along with treatment records to determine the impact of each of these vaccines compared to a placebo control. In the course of this work, Mannheimia haemolytica specific humeral immune response in a subset of calves will be described. Leukotoxin concentrations and whole cell specific IgG titers in saliva and serum at birth, prior to immunization, at booster immunization, and at weaning will be described demonstrating which vaccine potentially induces a protective titer and reduced clinical disease.

Research conducted by TX and MSU, in further collaboration with investigators at the University of Minnesota, the University of Saskatchewan, and the University of Liverpool, are evaluating the impact of postweaning commingling and/or truck transport on bovine respiratory coronavirus shedding in dairy calves over seven days post-weaning. Host immune gene expression, cortisol production, and proinflammatory cytokine production will be assessed before and after commingling and/or transport. The rationale is that disease is often worse in calves that have been transported and co-mingled, but it is not known which of these experiences contributes more to disease. Data that defines differences between transport and co-mingling are surprisingly rare. This research will separate the effects of co-mingling and transport on susceptibility of calves to infection by bovine coronavirus, and it will also incorporate assessment of host responses to assess the impact of individual animal stress and immunosuppression on virus shedding.

Investigators at MSU, UGA, and TX have active collaborative research on physiological stress, nutrition, and supplemental therapies on the occurrence and presentation of BRD. Multiple active research projects aim to determine the effect of supplementing mineral (Cu, Zn, Mg, Mn) formulations or injectable products to cattle with respect to respiratory disease outcomes, upper respiratory tract microbiomes, and immune responses. This work would enhance knowledge and decision making regarding the use of formulated feed rations and injectable mineral products with regard to respiratory disease risk and control.

 

Objective 4: Characterize and model system-level, economic, and societal drivers of respiratory disease in cattle production

Researchers at SD, UGA, MSU, TX, Nebraska (NE), and TN plan to continue and expand upon work which determine how attributes of cattle production systems including epidemiological, societal, and economic forces contribute to BRD, and to develop ways to promote changes in those systems to reduce the occurrence of BRD and improve cattle health, welfare, productivity, and antimicrobial stewardship.

Long-term investigations into beef cattle pneumonia cases within feedlot systems are ongoing. Collaborators from KS, MSU, CSU, and TX are evaluating epidemiological contributors to BRD across feedlot pens and whole systems to identify key risk factors and predictive drivers of disease occurrence and severity.

Investigators at MSU, KS, and TX aim to determine how preweaning vaccination and postweaning transport through an auction market and order buyer facility impacts the rate and severity of BRD in post-weaned beef calves during the backgrounding period. This work aims to provide details regarding how preweaning vaccination and postweaning commingling impact BRD risk.

Researchers at KS, TX, MSU, and CSU, in conjunction with collaborators at Rowan University and several participating industry partners, are assessing the economic impact of late-day pulmonary disease in feedlot cattle. Specifically, this work aims to develop econometric models which incorporate contextual information about specific cattle groups, cost of potential interventions, expected efficacy of interventions, error frequency, type, and cost. Economic estimates will guide decision makers in determining the optimum course of action for each pen to mitigate the impacts of respiratory and pulmonary diseases.

 

Objective 5: Translate collaborations and knowledge of respiratory disease research into practical applications.

The NC1192 multistate project has been a leader in delivering scientific presentations regarding the latest developments in research and evidence-based recommendations related to BRD, through presentation of the Bovine Respiratory Disease Symposium in 2009, 2014, 2019, and, most recently in 2024. The BRD Symposium is a two-day conference with speakers representing both the beef and dairy cattle industries, focused on topics including microbiology, immunology, epidemiology, and animal husbandry and management. Attendees have included veterinarians, scientists, educators, and cattle producers from the United States, Canada, Australia, and elsewhere in the world. The Symposium has included poster sessions, meals, and in some years, breakout sessions, all of which have facilitated discussion of new discoveries in the field of BRD. In 2009, 2014, and 2019 the proceedings of the Symposium were published in the journal Animal Health Research Reviews; in 2024 the proceedings were made available online at the Symposium website (http://brdsymposium.com/). The BRD Symposium has been held in conjunction with the summer meeting of the Academy of Veterinary Consultants (AVC), which has provided valuable assistance with organizing and advertising the event. The 2029 BRD Symposium will be organized and presented by NC1192, with organization efforts beginning in the second half of 2027. Members of the BRD Symposium Organizing Committee will be identified, with a chair or two co-chairs identified from within NC1192, and additional members representing scientists working in BRD and who may or may not be members of NC1192. In 2027 we will confirm with AVC that the 2029 Symposium will again be held in conjunction with the Summer AVC meeting, which we believe is likely, as AVC has in past years contacted NC1192 in advance of the expected Symposium to offer their support.  A theme for the 2029 Symposium will be established and a slate of speakers on various relevant topics will be developed. The two-day format has been popular with attendees and allows delivery of a good balance of information from various disciplines; thus it is likely the 2029 Symposium will be a two-day event. Based on attendance in past years, we anticipate that 200-300 people will attend the 2029 BRD Symposium

Researchers in SD, MSU, AU, and Louisiana (LA) plan to continue and promote exchange among scientists, veterinarians, allied industry professionals, and cattle producers to advance respiratory research initiatives, to implement outreach, to disseminate research results, and to facilitate the translation of research findings to practical field applications.

All stations will participate in the development of publications for veterinary and producer-based publications such as, but not limited to, The Bovine Practitioner, Animal Health Research and Reviews, and Veterinary Clinics of North America: Large Animal Practice.

Collaborators from LA, AU, MSU, and KSU plan to incorporate findings from all other Objectives into extension programs for beef and dairy producers, including the Beef Quality Assurance Certification program and Master Cattlemen programs. Findings will also be incorporated into continuing education courses for veterinarians and cattle producers.

Measurement of Progress and Results

Outputs

• (1) Comments: Advanced understanding of the interactions among host biology, pathogen virulence traits, and environmental conditions that collectively influence the onset and progression of bovine respiratory disease (BRD).
• (2) Comments: Identified and characterized emerging respiratory pathogens and developed experimental and analytical models to determine their contribution to BRD pathogenesis.
• (3) Comments: Developed and validated clinical scoring tools, diagnostic assays, biometric indicators, and predictive models to improve detection and case definition of BRD in research and production environments.
• (4) Comments: Designed and tested prevention and control strategies, including management interventions, immunization programs, and therapeutic approaches that reduce the frequency and severity of BRD.
• (5) Comments: Created systems-based models describing economic and decision-making processes that either mitigate or increase BRD risk, and formulated approaches to promote producer adoption of evidence-based practices and technologies.
• (6) Comments: Disseminated research outcomes through open-access, peer-reviewed publications, extension articles, conference presentations, webinars, workshops, and professional symposia to enhance knowledge transfer across academic, veterinary, and producer audiences.
• (7) Comments: Planned assessment of the 2029 BRD Symposium’s impact using attendee feedback collected via interactive polling tools (e.g., Slido) and written surveys distributed in registration materials; the compiled results will guide the design and content of the 2034 Symposium.
• (8) Comments: Submitted multidisciplinary, multi-institutional grant applications to federal agencies to secure support for collaborative research advancing the prevention and management of respiratory disease in cattle operations.

Outcomes or Projected Impacts

• (1) Veterinarians and producers will gain access to evidence-based guidance for preventing and managing bovine respiratory disease (BRD) within contemporary U.S. beef and dairy production systems.
• (2) Academic, government, and industry researchers will benefit from foundational and applied data on respiratory disease, supporting continued advancements in related scientific disciplines.
• (3) Educators, researchers, and policy makers will have access to the latest findings on the biological and environmental mechanisms underlying respiratory disease development, in addition to evidence-based approaches for disease mitigation and prevention.
• (4) Ongoing outreach will ensure that veterinarians and producers remain informed of emerging research, innovative technologies, and best practices for effectively reducing the incidence and economic impact of BRD across the cattle industry.

Milestones

(2026):Objective 1: KS, TX, CO, and MSU will conduct coordinated investigations into pulmonary pathology in late-day feedlot mortalities to determine the prevalence and histopathologic features of bronchopneumonia (BP), acute interstitial pneumonia (AIP), and bronchopneumonia with an interstitial component (BIP). WSU and TX will continue genomic and pathogen profiling to identify loci associated with respiratory disease resistance using large multi-state datasets. TN and AU will expand transcriptomic studies of persistently infected (PI) BVDV cattle to identify pathways of chronic inflammation and immune dysregulation. TN, WSU, and SD will investigate post-weaning immune function in calves exposed to in-utero BVDV infection, while UCD and Atlantic Tech University will characterize environmental risk factors associated with respiratory disease onset in cattle populations. AU, UGA, and MSU will evaluate susceptibility and viral pathogenesis of H5N1 infection in Jersey cattle as a model for cross-species influenza transmission. Researchers at MSU and TX will develop a primary bovine epithelia cell model to better evaluate host-pathogen relationships occurring in BRD.

(2026):Objective 2: TN, KS, and TX will collaborate to determine patterns of dam-to-calf transmission of respiratory pathobionts, establishing the timing and impact of pathogen carriage on early-life health. KS, TX, CSU, and MSU will develop a supervised machine learning pipeline using digital histopathology images from late-day mortality cases to automate lesion detection and classification of BRD. TN and WSU will develop a saliva-based antibody assay for Mannheimia haemolytica to support non-invasive diagnostics. WSU and TX will also integrate genomic, clinical, and field data to refine predictive diagnostic algorithms for BRD occurrence and severity.

(2027):Objective 3: MSU and TX will perform functional studies evaluating mRNA-mediated activation of ALOX15 expression in bovine airway cells to characterize lipoxin-mediated inflammation resolution pathways. TN and WSU will complete a randomized field trial comparing two commercial Mannheimia haemolytica vaccines in pre-weaned Holstein heifers, integrating clinical scoring, ultrasound, and serologic responses. TX and MSU, in collaboration with other institutes, will evaluate the separate and combined effects of postweaning commingling and transport on bovine coronavirus shedding and host immune response. MSU, UGA, and TX will assess the impact of trace mineral supplementation and injectable formulations on respiratory outcomes, airway microbiome composition, and immune profiles to develop science-based nutritional intervention strategies.

(2027):Objective 4: SD, UGA, MSU, TX, NE, and TN will expand system-level studies linking epidemiologic, societal, and economic factors to BRD risk and management outcomes. KS, MSU, CSU, and TX will evaluate pen-level and feedlot-level epidemiological determinants of respiratory disease to identify predictive risk factors for BRD morbidity and mortality. KS, TX, MSU, and CSU will continue economic modeling of late-day pulmonary disease to estimate intervention costs and inform decision-making frameworks. MSU, KS, and TX will examine how preweaning vaccination and market transport influence BRD rates during the backgrounding period, supporting refinement of producer management practices that enhance animal health and welfare while improving antimicrobial stewardship.

(2027):Objective 5: All participating stations will meet annually to present findings, develop new collaborative proposals, and refine multi-institutional research priorities. NC1192 will organize and host the 2029 Bovine Respiratory Disease Symposium likely in partnership with the Academy of Veterinary Consultants, with planning initiated in 2027 and the final program to be completed in 2028. Members from SD, MSU, AU, and LA will coordinate extension activities to translate scientific findings into producer and veterinary education programs. All stations will contribute to peer-reviewed and extension-oriented publications, conference presentations, webinars, and workshops to ensure timely dissemination of project outcomes.

Projected Participation

View Appendix E: Participation

Outreach Plan

Information generated through this project will be communicated broadly through publication in peer-reviewed scientific journals. Members of NC1192 maintain their dedication to applied communication, where members consistently contribute to producer-focused and industry publications to ensure that new knowledge is accessible to veterinarians, producers, and allied professionals. Peer-reviewed publication and outreach in producer-oriented literature will remain a central priority for dissemination throughout the project period.

Members of NC1192 will continue to present new findings and methodologies at national and international meetings, including but not limited to the American Association of Veterinary Laboratory Diagnosticians–U.S. Animal Health Association (AAVLD–USAHA) annual meeting, the Conference of Research Workers in Animal Diseases (CRWAD), the American Association of Bovine Practitioners (AABP), and the Academy of Veterinary Consultants (AVC). These presentations will enable direct exchange of information among researchers, veterinarians, and producers, supporting technology transfer of validated diagnostic assays, vaccines, and management strategies to the broader veterinary diagnostic community and livestock industry.

Engagement with the livestock sector will continue through partnerships with national organizations such as USDA, AABP, AVC, and the National Cattlemen’s Beef Association (NCBA). NC1192 will actively participate in these groups to maintain open dialogue and promote the adoption of science-based practices that mitigate respiratory disease. As part of its outreach mission, the group will host the Bovine Respiratory Disease Symposium during this project cycle, a recurring event held every five years since 2009 that attracts veterinarians, producers, researchers, and policymakers.

Organization/Governance

The Technical Committee will consist of one voting member from each cooperating station as appointed or otherwise designated by that station, with an Administrative Advisor. A President and Secretary of the Technical Committee will be elected by a majority vote of the committee; each will serve a one-year term. Annual meetings will be held at a time and site agreed on by the Technical Committee, with the majority of meetings held in conjunction with a national meeting of an organization related to bovine health; this is expected to continue at CRWAD in conjunction with the annual USDA Meeting for Principal Investigators. At the annual meeting, the Secretary will record the minutes and submit them to the Technical Committee for approval. The President and Secretary will prepare the annual report summarizing material supplied by the voting member from each participating station and, following approval of the report by the Technical Committee, will submit the report to the Administrative Advisor for dissemination to the appropriate parties.

Literature Cited

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16. Adkins M, Moisa S, Beever J, Lear A. Targeted Transcriptome Analysis of Beef Cattle Persistently Infected with Bovine Viral Diarrhea Virus. Genes (Basel). 2024 Nov 22;15(12):1500. doi: https://doi.org/10.3390/genes15121500.

Attachments

Land Grant Participating States/Institutions

CA, GA, KS, MS, NY, TN, WA

Non Land Grant Participating States/Institutions