Progress 09/15/06 to 09/14/08
Outputs
OUTPUTS: Bovine Respiratory Disease (BRD) costs cattlemen more than all other diseases combined. A rapid measure of respiratory health has the potential to have a significant impact on the beef industry by assisting with the successful management of bovine during the feeding period. Identifying at-risk animals before they become sick and confirming disease in suspect cattle are two areas where objective measures of respiratory health could be used to improve management practices. Ekips Technologies, Inc. has been developing a method of assessing respiratory health on the basis of exhaled immune system biomarkers. Phase I research efforts demonstrated a significant relationship between the level of nitric oxide (NO) in exhaled breath of beef calves received at a research facility and the severity of BRD in terms of number of times treated and average daily weight gain. Because BRD is a complex disease, it is feasible that more than one molecule will be required to adequately assess respiratory health. As such, we have investigated several additional molecules of potential importance in BRD. The objective of this project was to adapt our existing LAS technology to demonstrate rapid measurement of additional biomolecules in the expired breath of healthy and BRD exposed bovine. PARTICIPANTS: Ekips personnel included: Gina McMillen, project director, oversaw all aspects of project, daily data collection and analysis; Chad Roller - engineer responsible for integrating instrument into testing environment, data collection and analysis; Khosrow Namjou - senior engineer responsible for design and operation of LAS instrument; Jim Jeffers - responsible for computer integration, electronic data capture and data analysis. Oklahoma State University (collaborator) personnel included: Clint Krehbiel, co-PI, oversaw all study-related activites at OSU and statistical analysis of data; D.L Step - co-PI, oversaw all clinical activities related to animal studies, including protocol design; Luis O. Burciaga-Robels, graduate student, involved in all daily activies of animal studies, data analysis and statistics. TARGET AUDIENCES: The commercial target of this technology is large confined animal feeding operations. At present, no studies have been conducted in the target audience. Plans to conduct such studies have been suspended until technical issues with lasers and instrumentation can be resolved. Past meetings and discussions with members of the target audience regarding our technology have been received favorably. PROJECT MODIFICATIONS: This project was originally designed around eNO measurement. Due to technical limitations with eNO measurement in bovine, however, our focus was modified to identify additional biomarkers of respiratory health. Despite the modification in biomarker focus, the overall goal to develop a rapid measure of bovine respiratory health has not changed. We modified our LAS instrument to measure carbon monoxide and determined that CO was a valid indicator of oxidative stress associated with BRD. Additionally, we identified nitrous oxide, a molecule closely related to NO as a potential biomarker. Results of a large-scale feedlot study in which we simultaneously measured CO, N2O and CO2 from BRD exposed cattle indicate that eN2O and eCO appear to have potential as diagnostic tools for cattle exhibiting signs of BRD. However, the present data suggest that production and/or detection of eN2O and eCO with current technologies may not be sensitive enough to predict a BRD event prior to clinical signs being observed. While significant progress has been made toward our original goal, additional work on instrumentation technology will need to be completed before commercialization efforts can be undertaken.
Impacts
Preliminary results have suggested that calves diagnosed with BRD have greater concentrations of eNO, however, exhaled eNO levels in bovine are at the lower level of current infrared laser absorption spectroscopy detection limits. Efforts to increase instrument sensitivity and response time with regard to eNO measurement in bovine have not significantly improved detection limits. Consequently, until better lasers can be developed (an ongoing effort by Ekips), low bovine eNO levels and animal-to-animal variation will prevent commercialization of a diagnostic test using eNO as a sole indicator. Due to the complexity of BRD and the likelihood that more than one molecule will be required to adequately assess bovine respiratory health, Phase II research efforts focused on identifying additional biomarkers of interest, including ethane (C2H6), nitrous oxide (N2O) and carbon monoxide (CO). An important outcome of our work has been the identification of a spectral region capable of measuring N2O, CO and CO2 simultaneously from one breath sample. This represents a distinct advantage of using laser spectroscopy and has facilitated our efforts to pursue multiple biomolecules concurrently. Both eN2O and eCO appear to have potential as diagnostic tools for cattle exhibiting signs of BRD. However, the present data suggest that production and/or detection of eN2O and eCO with current technologies may not be sensitive enough to predict a BRD event prior to clinical signs being observed. The development of a rapid breath analysis system to assess respiratory health in bovine represents a remarkable opportunity to improve diagnostic methods for BRD in commercial feeding operations. Early detection could reduce growing economic losses from excess medications, decreased weigh gain, lower carcass quality and higher labor costs. While significant progress has been made, additional work on instrumentation technology needs to be conducted before commercialization efforts can be undertaken. For example, improved mid-IR lasers are needed to allow greater flexibility in measuring multiple molecules. Moreover, successful commercialization of breath analysis sensors will require lower cost laser/detector modules. Accordingly, Ekips resources are being directed toward laser fabrication technology to achieve these objectives. This approach will establish a viable path for the ultimate commercialization of a rapid breath test to monitor bovine health.
Publications
- Luis O. Burciaga-Robles, MVZ, MC; Ben P. Holland, MS; D. L. Step, DVM, DACVIM; Clinton R. Krehbiel, PhD; Gina L. McMillen, DVM, PhD, Chris J. Richards, PhD, Lindsay Sims, BS, Jim D. Jeffers, MS, Khosrow Namjou, PhD, and Patrick J. McCann, PhD, Measurement of breath biomarkers and serum haptoglobin to predict bovine respiratory disease in newly received heifers, 2008. (To be submitted to the American Journal of Veterinary Research)
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Progress 09/15/06 to 09/14/07
Outputs
OUTPUTS: Bovine Respiratory Disease (BRD) costs cattlemen more than all other diseases combined. A rapid and sensitive diagnostic method for BRD is not currently available. The goal of this Phase II project is to develop a rapid exhaled biomarker based test to assess bovine respiratory health. Current technology limits the sensitivity and precision with which we are able to detect NO in bovine breath. However, since BRD is a complex disease, it is feasible that more than one molecule may be required to adequately assess respiratory health. As such, we have revised our LAS instrument to measure additional biomolecules of interest, have identified two additional molecules of potential importance in BRD, and have improved our technology to allow measurement of multiple molecules simultaneously . We have conducted two pilot studies and measured biomarker levels in healthy and experimentally challenged cattle. Additionally, we have integrated the technology into a research feedlot to
perform measurements on a group of high-risk calves on arrival, as pulled for BRD evaluation, and as pulled for routine weighing. General information regarding this project has been reported within the last year in the local newspapers. Once data analysis is complete (a task for Year 2), we plan to publish the results of the feedlot study and present data at a meeting.
PROJECT MODIFICATIONS: This project was originally designed around nitric oxide as a measure of respiratory health. Challenges with extremely low levels of exhaled NO in bovine breath and individual animal variation have not been overcome with modifications to our current technology. Until technology can be improved to address these issues with NO measurement in bovine, we have changed our biomarker focus to include N2O and CO. Due to the complexity of BRD and the likelihood that more than one biomarker will be needed in order to commercialize a product, we have always included the investigation of multiple molecules as an ongoing goal. Therefore, while not anticipated as a major objective in this Phase II project, our focus on N2O and CO has not changed the original goal of this project, to develop a rapid exhaled biomarker based test to assess bovine respiratory health.
Impacts
Results of our Year 1 work have identified limits in our current technology with regard to nitric oxide (NO) measurement in bovine. Since exhaled NO levels are so low in bovine, until better lasers are developed, we are limited in the precision and accuracy with which our measurements can be made. Ekips is currently working to develop better lasers. In the meantime, our LAS technology can readily be modified to measure additional molecules in breath. We have investigated and identified two additional molecules, nitrous oxide (N2O) and carbon monoxide (CO) of potential importance. Preliminary data from pilot studies has supported pursing these molecules in a large-scale study which we have just completed. We are actively analyzing data from a large feedlot study to determine the relationship of these biomarkers to other measures of respiratory disease in cattle (body temperature, clinical assessment, average daily gain, serum acute phase protein levels). This work will
continue in year 2 of this project. The technology and exhaled biomarkers being developed in this project will be important in improving diagnostic methods for BRD in commercial feeding operations. Current diagnostic methods for BRD are limited to visual observations and a follow-up body temperature test. Due to the heavy reliance on visual signs, early diagnosis of respiratory disease is difficult and the potential for an incorrect diagnosis is high. The end result of this work, a user-friendly instrument for the real-time assessment of exhaled biomarkers important in the assessment of respiratory health could impact cattle population management, health and economics.
Publications
- Roller, C.B., B.P. Holland, G. McMillen, D.L. Step, C.R. Krehbiel, K. Namjou, P.J. McCann. 2007. Measurement of exhaled nitric oxide in beef cattle using tunable diode laser absorption spectroscopy. Applied Optics, 46(8):1333-1342.
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