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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Environmentally Integrated Dairy Management Research » Research » Research Project #431196

Research Project: Improving Nutrient Use Efficiency and Mitigating Nutrient and Pathogen Losses from Dairy Production Systems

Location: Environmentally Integrated Dairy Management Research

2018 Annual Report

Objective 1: Develop land and manure management practices to improve crop and forage productivity, quality, and nutrient use efficiency; and reduce pathogens and losses of nutrients. Sub-objective 1.A. Conduct multi-scale experiments to investigate biochemical and physical processes controlling snowmelt, snowmelt infiltration and runoff, and nutrient losses from soil and manure. Sub-objective 1.B. Evaluate nutrient cycling, nitrous oxide and ammonia emissions, and nutrient and pathogen runoff losses with conventional and improved liquid dairy manure management practices for alfalfa production and in a silage corn-rye cover crop system. Sub-objective 1.C. Determine manure/crop management effects on N, P, and pathogens in runoff from dairy cropping systems. Sub-objective 1.D. Evaluate effects of alternative manure application methods on alfalfa-grass yield, quality, and silage fermentation characteristics. Sub-objective 1.E. Determine potential of fall-grown oat to capture nutrients from summer manure or fertilizer applications and produce a late-fall, energy-dense forage crop. Determine potential of spring wheat and barley for fall-forage yield, quality, and nutrient capture from mid-summer manure or fertilizer applications. Evaluate oat mixtures with wheat, triticale or cereal rye (1 planting) for total fall and spring forage yield (2 harvests), as well as nutrient capture. Objective 2. Develop, improve, calibrate, and validate model routines for nutrient management to assess environmental impacts, nutrient use efficiency, and economics at the farm scale. Objective 3: Characterize soil biodiversity and manure pathogen dynamics and interactions. Sub-objective 3.A. Conduct laboratory microcosm experiments to manipulate soil biodiversity and measure die-off rates of dairy manure-borne pathogens. Sub-objective 3.B. Conduct field studies relating agricultural cultivation practices to soil biodiversity and die-off rates of manure-related pathogens. Objective 4. Reduce nutrient losses from replacement dairy heifer production through management strategies that target nutrient use efficiency and growth performance. Sub-objective 4.A. Improve understanding of heifer development and growth, especially effects of genomic testing for residual feed intake (RFI) on nutrient-use efficiency and growth. Sub-objective 4.B. Determine effect of common management strategies (pen stocking rate, limit feeding, ionophores, diet composition, etc.) on nutrient-use efficiency and growth performance of heifers.

Improved management of dairy farms requires successfully managing its nutrient flows, both to maximize nutrient use by animals and crops to optimize profit, and to minimize nutrient loss to the environment. We will investigate most aspects of nutrient cycling throughout the dairy-farm system with a variety of methods and at different scales, including replicated field plots, field-scale paired watersheds, feeding trials with replicated pens of heifers, and computer modeling. We will also examine pathogen transport and viability at different points in the dairy farm system. Some experiments will investigate only one or two nutrient or pathogen pathways, while others will be more comprehensive, including, for example, surface runoff, gaseous emission, and plant removal. Computer modeling will investigate the whole-farm system. Our research team also has a longer-term goal, which is to integrate information across experiments to more completely describe, quantify, model, and manage the entire dairy-farm for improved efficiency and sustainability. Achieving this goal will help ensure the existence of profitable, environmentally acceptable dairy farming for coming decades.

Progress Report
For our established field site with small-scale plots, we completed the second winter of runoff collection and analyzed and compiled data. We completed lab-scale experiments to investigate the effect of manure application rate, placement in a snowpack, and solids content on nutrient leaching from manure during snowmelt. We published a manuscript on these results. We completed the second year of small scale field experiments to examine the impact of manure solids content on nutrient loss in runoff during snowmelt; specifically, we want to determine if manure with greater solids content lose less nutrients. An opportunity to conduct a field or production scale trial with three grass species (tall fescue, meadow fescue, and orchardgrass) occurred during FY18. Grasses were established during the summer of 2017, and manure or commercial fertilizer will be applied during summer 2018, with effects of each fertilizer evaluated with respect to silage fermentation and clostridial loads within grass silages. Study assessing the effects of dairy slurry applications on the growth and quality of fall-grown oat forages have been completed, data compiled and summarized, and manuscripts submitted and published. A study was initiated during Fall 2016 to assess spring wheat, spring barley, and oat as late-summer forage crops, assuming an approximate harvest date of 1 November. A second year of data collection has been completed, and all laboratory work is progressing. A third production year of the study will be initiated August 2018. An evaluation of mixtures of wheat, rye, and triticale with oat for fall forage production was initiated during Fall 2016. To date, one year of data has been collected and analyzed. The study will be conducted a second year with establishment of plots anticipated August 2018. We investigated the use of ARS' Integrated Farm Systems Model (IFSM to simulate whole-farm nitrogen cycling and use efficiency, and found that the model needs substantial improvement, which is not practical for a number of reasons. We made a long-term commitment to develop a new whole-farm dairy simulation model using modern structure, language, and science. We established a collaborative team of researchers from ARS, Univ. Wisconsin, UC-Davis, Univ. Arkansas, and DMI Innovation Center to develop the model. We held an initial team meeting in Chicago in summer 2017, established the model framework, and have begun coding the model in Python. Initial progress has been substantial and promising. Experiments on measuring pathogen inactivation as related to microbial diversity in groundwater have been completed. Next-Gen sequencing and diversity metrics have been completed. Data is being summarized for publication; the manuscript is being prepared. Experiments with young and gravid dairy heifers attempting to relate a genomic marker for residual feed intake in lactating cows with feed efficiency in growing replacement heifers were conducted during 2017. Heifers were placed on high and low nutritional planes within these studies. Feeding trials are completed; data is being summarized for publication; and one draft manuscript has been prepared, and is in internal review. An experiment assessing the effects of overstocking at the feedbunk in confinement rearing operations for replacement dairy heifers was initiated in June 2017. The study has been completed, data summarized, and the manuscript submitted and accepted for publication.

1. Microbial risk assessment method validated. Human exposure to gastrointestinal pathogens through environmental routes – particularly through drinking water – is an important public health burden. Quantitative microbial risk assessment (QMRA) is a method that can predict this burden, but QMRA predictions have never been validated for many pathogens. ARS researchers in Marshfield, Wisconsin, compared QMRA predictions to epidemiological measurements collected during outbreaks of waterborne gastrointestinal disease. Confirming that QMRA can reliably estimate human disease rates due to waterborne gastrointestinal pathogens. Policy-makers and agricultural engineers can use QMRA to accurately predict the health burden of pathogen exposure, including exposure to pathogens that originate on livestock farms and pollute ground and surface water during manure disposal. Such predicted health burdens are crucial to evaluating public health and environmental policies related to agriculture.

2. Sewer overflows can be distinguished from livestock pollution by the human microbe group Bacteroides. During heavy rainfall events sewers designed to carry sewage and stormwater together in a single pipe can overflow into waterways. At the same time, rainfall can transport land-applied manure to the same waterways and it can be difficult to identify the sources of pollution. In collaboration with scientists at Temple University, ARS scientists in Marshfield, Wisconsin determined that the concentrations of two groups of bacteria in river water, human Bacteroides and coliforms, were highly correlated with overflow events of combined sewers. On the other hand, other microorganisms often considered to be indicators of pollution, E. coli, pepper mild mottle virus, and human polyomavirus, were not related to the overflow events. These results will guide future work in reducing the negative health effects when people recreate in waters impacted by combined sewer overflows.

3. Water quality impact from legacy soil phosphorus can be substantial in the Chesapeake Bay watershed. Agricultural phosphorus (P) loss from fields and water quality degradation continues to be an issue in the Chesapeake Bay watershed. Since many of the soils in the watershed have high P levels, information is needed on how long it will take to reduce soil P and how much related P loss will decrease. ARS researchers in Madison, Wisconsin used the Annual P Loss Estimator (APLE) model to estimate soil P drawdown and P loss for cropland in Maryland. They showed that reducing soil P throughout the state to agronomic levels could reduce P loss to the Chesapeake Bay by 42%. However, it may take 30-40 years to reach the 42% target. Combining soil P drawdown with aggressive soil conservation could reduce P loss by 63%. There is potential to substantially reduce P loss from Maryland soils to the Chesapeake Bay, but it will require a continued effort to reduce both soil P and P transport from all cropland.

4. Data gaps are filled for dairy heifer management guidelines. Dairy producers have Extension and Industry guidelines for feeding and housing heifers to ensure profitable production. However, there is little data supporting guidelines that address two common situations that could reduce production, which are overcrowding in free-stall barns, and how to feed straw in energy-rich diets to prevent heifers from getting too heavy. To fill these data gaps, ARS researchers in Marshfield, Wisconsin evaluated the effects of pen stocking density and straw processing in diets on the growth, feed sorting, behavior, and hygiene of Holstein dairy heifers in a free-stall barn. Heifers sorted feed more aggressively when straw was poorly processed, but this did not affect their growth since feeding was based on complete consumption in 24 hours. However, overstocking pens increased the variability among heifers in daily weight gains and hygiene scores, suggesting that some heifers in overstocked pens rested in manure alleys when no stall was available. This information was circulated widely in producer publications and supports industry guidelines for best ways to feed straw and avoid excessive overcrowding to achieve desired heifer performance and well-being.

5. Co-product from novel alfalfa harvesting strategy can be used in dairy heifer feeds. A novel alfalfa harvesting strategy where leaves and stems are harvested and used separately in dairy cattle feed can substantially improve the efficiency of alfalfa production on farms by reducing the number of harvests required and providing more protein feeding options. However, there is a need to develop ways to feed the alfalfa stems to make the novel harvesting viable. One option is to use stems in heifer diets since producers commonly dilute these diets with low-quality forages, such as wheat straw, to prevent heifers from getting too heavy. ARS scientists in Marshfield, Wisconsin, in collaboration with the University of Wisconsin, used alfalfa stems in heifer diets and found that they were just as effective as wheat straw to maintain desirable heifer condition and growth. This proof of concept research will help scientists continue development of their novel alfalfa harvesting strategy, which promises to improve the efficiency of dairy production.

Review Publications
Burch, T.R., Spencer, S.K., Borchardt, S.S., Larson, R.A., Borchardt, M.A. 2018. Opportunities for optimization: fate of manure-borne pathogens during anaerobic digestion and solids separation. Journal of Environmental Quality. 47:336-344.
Coblentz, W.K., Akins, M.S. 2018. Recent advances and future technologies for baled silages. Journal of Dairy Science. 101:4076-4092.
Coblentz, W.K., Akins, M.S., Esser, N.M., Ogden, R.K., Gelsinger, S.L. 2018. Effects of straw processing and pen overstocking on the growth performance and sorting characteristics of diets offered to replacement Holstein dairy heifers. Journal of Dairy Science. 101:1074-1087.
Burch, T.R., Sadowsky, M.J., Lapara, T.M. 2017. The effect of different treatment technologies on the fate of antibiotic resistance genes and class 1 integrons after the application of residual municipal wastewater solids to soil. Journal of Environmental Science and Technology. 51:14225-14232.
Ricci, A., Iotti, B., Bertero, A., Reed, K., Pascottini, O. 2018. Assessment of the temperature cut-off point by a commercial intravaginal device to predict parturition in Piedmontese beef cows. Theriogenology. 10.1016/j.theriogenology.2018.02.009.
Clark, J.K., Coffey, K.P., Coblentz, W.K., Shanks, B.C., Caldwell, J.D., Muck, R.E., Philipp, D., Borchardt, M.A., Rhein, R.T., Jokela, W.E., Backes, E.A., Bertram, M.G., Smith, W.B. 2018. Voluntary intake and digestibility by sheep of alfalfa ensiled at different moisture concentrations following fertilization with dairy slurry. Journal of Animal Science. 96:964-974.
Gaillard, R.K., Jones, C.D., Ingraham, P., Collier, S., Izaurralde, R.C., Jokela, W.E., Osterholz, W., Salas, W., Vadas, P.A., Ruark, M. 2018. Underestimation of simulated N2O flux in a model comparison of DayCent, DNDC, and EPIC. Ecological Applications. 28:694-708.
Vadas, P.A., Stock, M.N., Feyereisen, G.W., Arriaga, F.J., Good, L.W., Karthikeyan, K.G. 2018. Effect of temperature and manure placement in a snowpack on nutrient release from dairy manure during snowmelt. Journal of Environmental Quality. 47:848-855.
Vadas, P.A., Fiorellino, N.M., Coale, F.J., Kratochvil, R., Mulkey, A.S. 2018. Estimating legacy soil phosphorus impacts on phosphorus loss in the Chesapeake Bay Watershed. Journal of Environmental Quality. 47:480-486.
Wang, Z., Zhang, T.Q., Vadas, P.A., Qi, Z.M., Wellen, C. 2018. Modeling phosphorus losses from soils amended with cattle manure and chemical fertilizers. Science of the Total Environment. 639:580-587.
McGinnis, S., Spencer, S.K., Firnstahl, A., Stokdyk, J., Borchardt, M.A., McCarthy, D.T., Murphy, H.M. 2017. Human bacteroides and total coliforms as indicators of recent combined sewer overflows and rain events in urban creeks. Science of the Total Environment. 630:697-976.
Burch, T.R., Spencer, S.K., Stokdyk, J.P., Kieke, B.A., Larson, R.A., Firnstahl, A.D., Rule, A.M., Borchardt, M.A. 2017. Quantitative microbial risk assessment for spray irrigation of dairy manure based on an empirical fate and transport model. Environmental Health Perspectives.
Fiorellino, N.M., McGrath, J.M., Vadas, P.A., Bolster, C.H., Coale, F.J. 2017. Use of annual phosphorus loss estimator (APLE) model to evaluate a phosphorus index. Journal of Environmental Quality. doi:10.2134/jeq2016.05.0203 46(6):1380-1387.
Holly, M.A., Kleinman, P.J., Bryant, R.B., Bjorneberg, D.L., Rotz, C.A., Baker, J.M., Boggess, M.V., Brauer, D.K., Chintala, R., Feyereisen, G.W., Gamble, J.D., Leytem, A.B., Reed, K., Vadas, P.A., Waldrip, H. 2018. Identifying challenges and opportunities for improved nutrient management through U.S.D.A's Dairy Agroecosystem Working Group. Journal of Dairy Science. 101(7):6632-6641.
Bolster, C.H., Vadas, P.A. 2018. Comparison of two methods for calculating the P sorption capacity parameter in soils. Soil Science Society of America Journal. 82(2):493-501.