Location: Environmentally Integrated Dairy Management Research
2022 Annual Report
Objectives
Objective 1: Quantify the ability of innovative dairy nutrient management practices to improve soil nutrient distribution and runoff water quality.
1A: Evaluate the association between Runoff Risk Advisory Forecast (RRAF) forecasts and microbial contamination of private household wells in the dairy region of northeastern Wisconsin.
1B: Develop a prediction tool that expands upon the RRAF, incorporating groundwater-related factors, to be able to predict and avoid manure runoff contamination of private household wells.
1C: Quantify pasture management effects on surface runoff water quality, soil nutrient distribution, and soil health measures.
1D: Determine the impacts of using high-resolution soil mapping on crop nutrient recommendations and loss indices at the UW-Marshfield Agricultural Research Station.
1E: Characterize soil properties and evaluate nutrient attenuation in soils and shallow subsurface runoff flows of select riparian buffers adjoining forage crop fields at UW-MARS and the U.S. Dairy Forage Research Center (USDFRC) Prairie du Sac Research Farm using field sampling and modeling approaches.
Objective 2: Evaluate the ability of novel dairy manure management practices to improve on-farm nutrient use efficiency.
2A: Evaluate the impact of separated dairy manure solids and heifer manure on corn yield, soil biological indicators, and nitrate leaching over multiple growing seasons.
Objective 3: Develop and apply improved quantitative microbial risk assessment (QMRA) methods to assess the public health impacts of alternative dairy production practices.
3A: Develop a screening-level exposure and risk assessment model for waterborne gastrointestinal pathogens in private wells contaminated by human and/or bovine fecal material.
3B: Develop an updated, outbreak-based Cryptosporidium dose-response model.
3C: Conduct a state-wide QMRA for transmission of antibiotic resistant bacteria (ARB) via private wells in Wisconsin.
Approach
Dairy production has intensified over the past 30 years, shifting from many small farms to fewer large farms. Driven by goals of efficiency and economic productivity, this change has benefited producers and consumers alike. However, it has also altered the environmental impacts of dairy production because larger farms tend to concentrate livestock manure in smaller geographic regions and require more intense manure applications compared to less concentrated production systems, placing increased pressure on soil health and water quality as a result. At the same time, the pressures facing modern dairy operations, including high input costs, uncertain milk and commodity prices, and increasing regulatory demands and public scrutiny, have led to renewed interest in less intensive production practices (e.g., grazing-based systems). Technical recommendations for co-optimizing production and environmental impacts in these systems is limited. The proposed research will focus on impacts of dairy management practices on soil health, nutrient loss in water runoff and leaching, and public health risks of antimicrobial resistance and pathogen exposures. The approach is collaborative, including major contributions from the University of Wisconsin-Marshfield Agricultural Research Station (UW-MARS), UW-Madison, UW-Extension, the National Cooperative Soil Survey, and the U.S. Geological Survey Upper Midwest Water Science Center, among others. The approach also consists of observational and experimental field work along with complementary mathematical modeling efforts. Observational field work is based on randomized sampling of private wells in northeast Wisconsin and multivariate predictive statistical modeling. Field work is based on continued use and development of our long-standing field facilities at UW-MARS. And additional mathematical modeling is largely grounded in the quantitative microbial risk assessment (QMRA) approach. This work impacts dairy and forage production systems in the upper Midwest and elsewhere. Products and outcomes consist of best management practices for nutrients, zoonotic pathogens, and antimicrobial resistance; fundamental knowledge about soil health and function; and improved tools for QMRAs. Stakeholders include dairy producers, the dairy industry, environmental and public health agencies, and rural residents.
Progress Report
Objective 1, Sub-objectives 1A and 1B: We have made some progress in initiating the agreement with our U.S. Geological Survey collaborators to complete this work and plan to begin enrollment of study participants in late summer/early fall of 2022. However, more substantial progress has been delayed by the recent retirement of a scientist and will resume once the replacement is in place.
Objective 1, Sub-objective 1C: Data collection for the treatment phase of a paired watershed study comparing surface water quality impacts from three grazing management regimes (compared to routine hay harvest and manure application) was completed 2021. These data have since been statistically analyzed and summarized in a draft manuscript. In addition, a long-term water quality data set covering the lifespan of the experiment to date (2007-2022) was recently completed. We are working with a University of Wisconsin scientist on applying the latest version of the Wisconsin phosphorus site index model to evaluate P loss predictions during this period. A new calibration phase initiated in June 2022 with watersheds with managed heifer grazing and will continue for approximately two years before the next prescribed grazing management experiment starts.
Objective 1, Sub-objective 1D: The Wisconsin Natural Resources Conservation Service (NRCS) State Soil Scientist and State Soil Health Specialist/Assistant State Soil Scientist were contacted to begin the initial phase of the digital remapping process for the Marshfield Agricultural Research Station (MARS). We will work directly with the NRCS collaborators during the digital remapping process and develop a specific field verification/calibration plan for the MARS remapping project.
Objective 1, Sub-objective 1E: Sites that were originally planned for establishment at the Prairie du Sac research farm were not feasible due to inherent site limitations (extremely steep and high stream banks) along the Wisconsin River in that area. As an alternative, new sites were identified along a forested section of the Little Eau Pleine River on University of Wisconsin property. These sites are located approximately two miles south of the MARS location in Stratford, Wisconsin, along with the other field experiments and buffer sites. Sampling instrumentation will be installed during the summer/fall of 2022. Another unexpected event was that our collaborator has left the University and is no longer able to participate in the planned research collaboration. We are determining how to best move forward on modeling aspects of the project, with assistance from the collaborator on technical support on model parameterization once sufficient data are collected (modeling runs planned for 2025-2026).
Objective 2, Sub-objective 2A: The second year of monitoring for this experiment is now underway. A second application of separated dairy manure solids and bedded heifer pack manure will be done this fall after corn silage harvest. We have added greenhouse gas measurements as a compliment to the soil nutrient/health and nitrogen leaching data, enabling quantitative greenhouse gas (GHG) flux estimates. Repeated measurements of soil nutrient dynamics (carbon, nitrogen, and phosphorus), nitrogen leaching, and GHG fluxes will also provide an important data set to help calibrate the forthcoming Ruminant Farm Systems Model (RuFaS).
Objective 3, Sub-objective 3A: County-level livestock populations were located and retrieved from the National Agricultural Statistics Service throughout spring of 2022, including counts of both beef and dairy cattle in all of Wisconsin’s 72 counties. Escherichia coli test data for private wells in all 72 counties and total human populations were also retrieved at the same time. We have yet to estimate the proportion of residents on private wells (versus public water systems) and to complete retrieval of Wisconsin Department of Health Service reportable disease data for model validation. That puts us approximately two months behind on our 12-month timeline, though given the extent of remaining work and time commitments for fiscal year 2022, we should be able to make that time up in late summer or early fall of 2022.
Objective 3, Sub-objective 3B: Exposure assessments have been completed for 10 outbreaks involving Cryptosporidium parvum or Cryptosporidium hominis. We used Monte Carlo simulations to assess the variability and uncertainty of individual-level doses involved in outbreaks and to parameterize them in terms of negative binomial models that can be used for initial no-pooling dose-response assessments.
Objective 3, Sub-objective 3C: There was no work and/or milestones planned for fiscal year 2022.
Accomplishments
1. Quantified the real-world effectiveness of farm-scale anaerobic digestion for reducing antimicrobial resistance associated with dairy manure. Antimicrobial resistance contributes to 2.8 million infections in the United States annually, and livestock manure (including dairy manure) is an important reservoir of antimicrobial-resistant bacteria. Anaerobic digestion has been suggested as an effective treatment for limiting the spread of antimicrobial resistance from livestock manure, but most studies on this topic have been conducted in laboratory settings. ARS researchers in Marshfield, Wisconsin, worked with collaborators from the University of Wisconsin-Madison and the U.S. Geological Survey to sample dairy manure from multiple farm-scale digesters and examined the relative effects of digestion, seasonal changes, and facility-level variation. Surprisingly, seasonal and facility-to-facility variation were comparable to the effect of anaerobic digestion, emphasizing a need to investigate these factors more fully for potential management controls to reduce the proliferation of antimicrobial resistance. Furthermore, overall results indicate that real-world performance of anaerobic digestion for reducing antimicrobial resistance in manure is less than expected compared to previous laboratory-based studies. This suggests a need for a multiple barrier approach when it comes to controlling discharge of antimicrobial resistance from livestock production facilities.
2. Quantified the risk of infection associated with public wells contaminated by human and animal fecal sources. Public wells that provide drinking water for many communities can be contaminated by fecal material from humans, agricultural livestock, and/or wildlife. This fecal material contains pathogenic microorganisms that cause gastrointestinal infections in humans, but the risk of infection associated with this contamination is unknown for most locations in the United States. ARS researchers in Marshfield, Wisconsin, collaborated with the U.S. Geological Survey and Minnesota Department of Health to estimate the risk of infection for public wells using an approach called quantitative microbial risk assessment. Risk estimates were based on nine different waterborne pathogens measured in nearly 1,000 water samples collected from 145 public wells throughout Minnesota. Results indicate that risk was highest for public wells that provide water for people outside their homes (also known as “non-community” wells, like at restaurants or gas stations). Risk was lower for public wells that provide residential drinking water to homes. However, the reduction in risk associated with disinfection of public well water was unexpectedly low. This occurred because risk estimates were dominated by the protozoan parasite Cryptosporidium, and Cryptosporidium is resistant to the predominant form of disinfection used in the study (such as chlorine disinfection). This study demonstrates that infectious disease risk could be reduced by adding additional treatment steps like filtration or ultraviolet disinfection to many public wells. It also suggests that infection risk for non-disinfecting public wells is comparable to that from private wells in aquifers influenced by livestock manure, whereas the risk for non-community public wells is higher.
Review Publications
Coblentz, W.K., Ottman, M.J. 2022. Effects of harvest date and growth stage on triticale forages in the southwest USA: Kinetics of in-vitro disappearance of fiber and dry matter. Journal of Animal Science. 100(3):1-18. https://doi.org/10.1093/jas/skac020.
Coblentz, W.K., Ottman, M.J., Kieke, B.A. 2022. Effects of harvest date and growth stage on triticale forages in the southwest United States: agronomic characteristics, nutritive value, energy density, and in-vitro disappearance of dry matter and fiber. Journal of Animal Science. 100(3):1-16. https://doi.org/10.1093/jas/skac021.
Coblentz, W.K., Akins, M. 2022. Nutritive value and storage characteristics of large-round bales of alfalfa-grass or perennial-grass hays treated with a propionic acid-based preservative at elevated application presets. Applied Animal Science. 38(2):84-97. https://doi.org/10.15232/aas.2021-02243.
Ross, D.S., Young, E.O., Jaisi, D.P. 2021. Challenges and successes in identifying the transfer and transformation of phosphorus from soils to open waters and sediments. Soil Systems. 5(4):65. https://doi.org/10.3390/soilsystems5040065.
Burch, T.R., Firnstahl, A.D., Spencer, S.K., Larson, R.A., Borchardt, M.A. 2022. Fate and seasonality of antimicrobial resistance genes during full-scale anaerobic digestion of cattle manure across seven livestock production facilities. Journal of Environmental Quality. 51(3):352-363. https://doi.org/10.1002/jeq2.20350.
Burch, T.R., Stokdyk, J.P., Rice, N., Anderson, A.C., Walsh, J.F., Spencer, S.K., Firnstahl, A.D., Borchardt, M.A. 2022. Statewide quantitative microbial risk assessment for waterborne viruses, bacteria, and protozoa in public water supply wells in Minnesota. Environmental Science and Technology. 56(10):6315-6324. https://doi.org/10.1021/acs.est.1c06472.
Coblentz, W.K., Akins, M.S., Kieke, B. 2021. Storage characteristics of baled alfalfa-grass forages treated with a propionic-acid-based preservative or wrapped in stretch plastic film. Applied Animal Science. 37(5):505-518. https://doi.org/10.15232/aas.2021-02193.
Jaramillo, D.M., Sheridan, H., Soder, K.J., Dubeux, J. 2021. Enhancing the sustainability of temperate pasture systems through more diverse swards. Agronomy. 11(10):1912. https://doi.org/10.3390/agronomy11101912.
McGinnis, S.M., Burch, T.R., Murphy, H.M. 2022. Assessing the risk of acute gastrointestinal illness (AGI) acquired through recreational exposure to combined sewer overflow-impacted waters in Philadelphia: A quantitative microbial risk assessment. Microbial Risk Analysis. 20:100189. https://doi.org/10.1016/j.mran.2021.100189.
Niyigena, V., Coffey, K.P., Coblentz, W.K., Philipp, D., Althaber, D., Diaz Gomez, J., Rhein, R.T., Pruden, M.C. 2022. Intake, digestibility, rumen fermentation, and nitrogen balance in sheep offered alfalfa and tall fescue-mixtures harvested and ensiled after a frost. Animal Feed Science and Technology. 286:115268. https://doi.org/10.1016/j.anifeedsci.2022.115268.
Santos, E., Dubeux, J., Jaramillo, D.M., Garcia, L., Vendramini, J., Dolorenzo, N., Queiroz, L., Pereira-Neto, J., De Abreu, D., Ruiz-Moreno, M. 2022. Herbage accumulation and nutritive value of stockpiled limpograsses and 'Tifton 85' bermudagrass. Crop, Forage & Turfgrass Management. 8(1):1-7. https://doi.org/10.1002/cft2.20140.
Williams, K.T., Weigel, K.A., Coblentz, W.K., Esser, N.M., Schlesser, H., Hoffman, P.C., Ogden, R.K., Su, H., Akins, M.S. 2022. Effect of diet energy level and genomic residual feed intake on bred Holstein dairy heifer growth and feed efficiency. Journal of Dairy Science. 105(3):2201-2214. https://doi.org/10.3168/jds.2020-19982.
