• Objective 1. Develop management tools, strategies and systems for land application of animal manures and effluents that optimize efficient, environmentally friendly utilization of nutrients and are compatible with sustained land and water quality.

Scientists working on this task will use phosphorus indices and other shared modeling tools to evaluate the impacts of a variety of innovative practices on nutrient pollution of water. Phosphorus mass balances and runoff models will be compared across a several different cropping and pasture systems, in different soil types and climates, and with manure from different species. Intermediate results will be shared across the project and will be used to help formulate better general nutrient management planning strategies.

Scientists will study soils on highly erodible steep slopes under forage production, where high rates of animal manure have been applied for many years. Such soils already have elevated levels of phosphorus. Tillage and forage systems will be tested and evaluated to ameliorate areas of phosphorus overload. Plant uptake measurements and soil analyses will be used to evaluate effectiveness of tillage and different forage production management methods in reducing phosphorus levels at the soil surface. Concomitant changes in nitrate leaching from the sites to groundwater will also be monitored (AL). Various approaches to comprehensive nutrient management planning for pasture/broiler litter systems will be evaluated in AR.

Year-around forage production systems will be employed to test the feasibility of combining commercial nitrogen fertilizer with animal manure to provide a more balanced N-P-K ratio that is in line with forage nutrient requirements that enhance phosphorus uptake and reduce phosphorus soil tests. Annual ryegrass (the cool season grass crop) and warm season bermuda grass will be used in the first two years of the study. The following three years will test the effectiveness of substituting a legume crop (clover) in place of the commercial nitrogen to provide the nitrogen needed for the warm season bermuda grass crop. A two-year study of consecutive crops of forage sorghum, winter wheat, and forage sorghum followed by winter wheat with level border irrigation of collected feedlot runoff will be completed. Soil accumulation of P along with N, K, and salinity constituents as a function of application rate (0, 6and 12 in./yr , plus ground water to equal 12 in. per year moisture additions), soil profile depth, and crop removal will be evaluated for the converted rangeland site at TAES/USDA-ARS, Bushland, TX. Effects of cattle ration with lowered P vs. conventional P content in the diet of finishing cattle on runoff quality will be determined from 18 feedpens equipped with runoff monitors and samplers. Runoff studies will encompass comparisons of runoff quantity and quality with emphasis on P mass removals from conventional soil-surfaced feedpens vs. fly ash-surfaced pens. Experiments examining the feasibility of using buried vs. surface drip irrigation for feedlot runoff distribution as a feedlot effluent nutrient management method on the Southern High Plains will be established.

To provide more data and a balanced evaluation of phosphorus movement that includes other climates and cropping systems, scientists in WI and MN will study ways to reduce soluble phosphorus runoff from row cropped land, especially corn fields that have had manure applications. A combination of tillage systems (conservation tillage and conventional chisel plowing) with addition of low cost chemical amendments (alum, water treatment residuals, and fly ash) will be evaluated for their abilities to immobilize soluble phosphorus.

Multi-state collaboration among scientists will be an important component of this task, to validate the measurement methods and the models being developed. A variety of cropping systems and types of manure applications will be evaluated and compared, with the resulting data being used to increase reliability and broaden the applicability of the emission models.

Gas emissions from land-applied manure on pasture (AL and GA), sorghum and small grains crops (AL and MD), and no-tilled, deep-subsoil tilled and conventional tilled soybean row crops (GA) will be compared. Types of manures will include broiler litter, dairy slurry, swine lagoon effluent, and pasture grazed cattle manure. Emissions of ammonia, nitrous oxide, and methane will be studied and the results used to formulate generalized and localized emissions models.

The water quality impacts of grazing dairy cattle on pasture will be studied in regard to fecal coliform content in runoff water (LA). As part of an ongoing study, pasture plots will be artificially dosed with dairy cow manure in a manner similar to natural deposition during grazing. Rainfall simulators will provide various levels of runoff, and the impact of repeated rainfalls on fecal coliform counts in the runoff water will be measured. This segment of the project will address concerns about the dynamics of fecal bacteria in pasture situations during repeated rainfall events. Intermediate results of the study will be compared with those from the TN dairy experiments (objective 4) and the filter strip study (objective 2, IL, KS and VA).

A variable rate technology manure slurry applicator will be developed (IL) to enable the swine industry to meet nutrient management plan compliance. This project will incorporate application rate controls at progressively more sophisticated levels, to parallel the development of commercial fertilizer application equipment that is coupled with GPS software and hardware. The rate control algorithms and applicator results will be shared with scientists in WI and IN where work is being done on variable rate box- and tank-type manure spreaders.

Scientists will study how changes in livestock systems impact the overall farm nutrient management plan. In AR, strategies for in-building management of poultry litter and the effects of such strategies on the nutrient compositions and bulk properties of the litter will be examined. Litter treatments, building cleanout protocols and schedules, and litter storage options will be evaluated for their effects on farm comprehensive nutrient management plans. Interactions of the litter management strategies with the use of a phosphorus index on surface water quality will also be studied. In VA different nutrient management strategies for feeding stocker cattle will be compared, to determine the effects on soil fertility and surface water quality. On a fescue pasture system, broiler litter will be used as either a cattle feed supplement or as a soil fertilizer. Inorganic fertilizer application to the pasture and unsupplemented cattle feeding will be control treatments. The resulting changes in soil fertility levels (N, P, K, Ca, Mg, S, Cu and Zn) and runoff water quality will be assessed. Results from these experiments will be shared as the project group formulates recommendations for revising nutrient management plans to meet constraints on water quality and soil fertility.

• Objective 2. Develop, evaluate, and refine physical, chemical and biological treatment processes in engineered and natural systems for management of manures and other wastes.

Biological treatment systems that use aerobic, anaerobic and/or anoxic treatment will be studied at lab, pilot, and field scale. Treatment systems will be researched mainly for dairy (HI, CA, FL and GA) and swine (AL, LA, OR and NC). Procedures will include monitoring of typical waste treatment parameters such as chemical oxygen demand, dissolved oxygen, temperature, pH, nitrogen and phosphorus, but also odor reduction and pathogen destruction in some cases. Nutrient balances, especially for nitrogen and phosphorus, will be attempted in order to determine utilization potential for by-products. Researchers will be able to compare treatment efficiency, operational requirements, and costs for the various treatment alternatives.

Activated thermophilic aerobic digestion prior to mesophilic anaerobic digestion, and a dual biological fixed bed reactor will be researched for diluted or liquid dairy manure treatment and wastewater reuse (HI). Also, a microbial fingerprinting method for cattle (ruminant) waste will be developed using culture and gene probe techniques to measure microorganisms, which are characteristically found in intestines of cattle and other ruminants. This can be a tool to help assess public health issues involved in the reuse of the final treated effluent as well as impact of any product discharges. CA scientists will evaluate an anaerobic sequencing batch reactor (ASBR) and aerobic sequencing batch reactor (SBR) for dairy manure treatment; the evaluation will include determining extent of pathogen destruction. In FL, a fixed-film anaerobic digester for flushed dairy manure will be evaluated for treatment efficiency, odor reduction and pathogen reduction. A GA study will use a vertical drainage drying bed as primary treatment of flushed dairy manure, then the liquid will be anaerobically digested, and digester effluent will serve as a nutrient source for nutrient film hydroponics forage production. Two-stage biological anoxic/anaerobic treatment of swine wastewater will be studied at field scale (LA).

Swine lagoon liquid will be treated with diffused air and microbial augmentation in a partitioned pond before recycling for flushing swine manure (NC). Flushed swine manure will be treated with an upflow aerated biological filter after separation of coarse solids. Effluent will be recycled for flushing. Measures of odor, ammonia emission and pathogens will be performed.

A floating permeable cover for liquid manure lagoons and storages will be developed by OR scientists, with the goal to reduce ammonia emissions by 80 % and methane emissions by 50 % when compared to conventional treatment options.

A partitioned aquaculture system will be evaluated for algae and fish production and treatment of feedlot runoff (SC). Also, vegetated (grass and forest) filters (GA) and riparian buffers (MD) will be evaluated for treatment of runoff from land receiving animal manure. Methods will include flow rates and concentrations to determine mass balances and removal efficiencies for solids, nitrogen and phosphorus.

The long-term treatment of poultry lagoon liquid in a two-cell constructed wetland will continue in AL. This system has been in continuous operation since 1992. Vegetated wetlands will also be researched for treatment of swine lagoon liquid. In FL, vegetated wetlands and overland flow systems will be evaluated for treatment of dairy farm runoff and anaerobic lagoon effluent.

(SC) A partitioned aquaculture system (PAS) will be modified to provide a high rate of agricultural waste nutrient uptake and conversion into algae and high value fish and shellfish, offsetting the investment and operating cost of the water and waste treatment system. Four 0.5-acre high-rate algal/filter-feeder co-culture basins will be evaluated for application in treating concentrated agricultural wastewaters and watershed surface waters.

Several institutions will study runoff characteristics from a variety of soils, vegetative covers, and buffers. Movement of Cryptosporidium parvum and E. coli through soil and over vegetative filter strips will be evaluated by laboratory soil bed tests and by field measurements. Field tests will be performed in three states (IL, KS, VA) on existing filter strips. Experimental results will be used to develop models predicting transport and attenuation of the pathogens, and best management practices for the use of vegetative filter strips and tile drainage in pathogen removal. In GA, reduction of nitrogen, phosphorus, and chloride in runoff from areas receiving swine lagoon liquid based on either nitrogen or phosphorus content will be evaluated for vegetated buffers (10 m of grass and 30 m of forest). Scientists in MD will evaluate the use of available databases to quantify potential value of riparian forest buffers for the purpose of targeting areas for incentive programs.

Various pilot and field scale projects will use physical means (e. g., screen or centrifuge) to separate solids from flushed manure or from anaerobic lagoon sludge. Amendments such as hydrated lime or polyacrylamides will be tested for improving separation. Chemical amendments will also be tested for immobilizing phosphorus when applying manure to land. In addition, precipitation of phosphorus as a salt (struvite) will be tested for removing phosphorus from flushed dairy manure and swine lagoon liquid. For farms or regions that cannot effectively utilize manure nutrients and biosolids on nearby crops, separation of solids is necessary to make a more concentrated product for potential transport off farm. For farms that have accumulated high levels of phosphorus in soil, removal of phosphorus or immobilization of the phosphorus in manure applications may be necessary to allow continued application of manure.

In MD, poultry litter will receive various amendments to immobilize phosphorus when applying to land. Nutrient losses from stockpiled litter will also be evaluated.

Chemical amendments for immobilizing phosphorus and separating organic solids will be researched for swine waste (TN and WI), dairy wastewater, storm water or final-stage lagoon liquid (TX and FL), and swine lagoon liquid (NC). A variety of amendments will be tested, with economic considerations and applications for separated products being a strong focus of the systems being studied.

CA experiments will evaluate several methods for solid-liquid separation and pathogen reduction for flushed dairy manure. Screening and sedimentation will be examined in the laboratory and in the field. A vertical drainage drying bed will be evaluated in GA for removing solids from flushed dairy manure, and compared to other technologies (screening and gravity separators). FL scientists will study mechanical solids separation and sand separation for dairy farm wastewaters. In TN, solids/liquid separation and nutrient partitioning with a screw press will be evaluated for a range of total solids in flushed dairy manure.

Two universities will study improved ways to manage treatment lagoons. In AL, a pumping and filtration system will be developed and tested for removal of the lower sludge layer in aged animal waste anaerobic lagoons without disturbance of the supernatant. Two removal methods will be tested: a submersible solids handling pump and a modified swimming pool bottom cleaner. The sludge will be concentrated using an automatic blow-down screen filter. Characteristics of the material for agronomic purposes will be evaluated. Sludge from a swine anaerobic lagoon (NC) will be pumped with a sewage pump to a centrifuge. Efficiency of solids removal will be tested without amendment or with addition of hydrated lime. A reactor will be designed and tested at lab scale for struvite precipitation to remove phosphorus from swine anaerobic lagoon liquid. Test variables will include flow rate, pH, and magnesium addition.

Several institutions will study ways to utilize manure in nontraditional ways: as liquid chemical feedstocks, as dry fuel used alone or blended with fossil fuels, and as value-added compost. The focus will be on building integrated systems that are economically viable.

Thermochemical conversion of liquid swine manure to crude oil will move toward a pilot scale project (IL) and include economic evaluations as well as applications for the oil product. Results to date suggest the oil product can be used as a fuel or as a chemical feedstock to replace crude petroleum. Methods will be explored for integrating a manure processing plant with animal production facilities.

In TX cattle feedlot manure and broiler litter will be used as a biomass fuel with coal or lignite in 10:90 or 20:80 blends (biomass:coal or lignite) for combustion experiments for energy production and beneficial utilization of manure as an alternative to land application of manure in nutrient enriched watersheds. The fuels will also be evaluated as a reburn fuel for NOx and SOx reduction a coal-fired or lignite power plant situation. Experiments will be conducted both small scale and at a large pilot plant. In an AR experiment, broiler litter will be blended with green hardwood sawdust and/or wood pellets as a biomass fuel. Heat from combustion will be used for space heating broiler houses during brooding. Experiments will quantify combustion efficiency, exhaust gas composition and ash production/utilization.

Studies in LA will focus on matching available substrates such as sugar cane bagasse, rice straw or hulls, wood chips or paper mill wastes with aquacultural wastes in each area of the state. Composting technologies will be investigated, and automated instrumentation for measurement and control of composting systems will be built. Processing of screened dairy manure solids and solids removed by chemical treatments in a plate clarifier will be studied for possible conversion of dairy manure solids into a potting media product for the plant nursery industry using a drum composter (FL).

Alternative technologies will be evaluated in OR for capturing nutrients from manure in a sufficiently stable and concentrated form to allow them to be economically transported to an alternate watershed that is nitrogen and/or phosphorus deficient.

• Objective 3. Develop methodology, technology, and management practices to reduce odors, gases, airborne microflora, particulate matter, and other airborne emissions from animal production systems.

Sampling of airborne contaminants that are emitted from animal housing facilities and associated manure storage systems has been carried out by various member states (MN, IN, IL, IA, NC, OR, TX). Procedures and protocols for collecting and measuring these airborne emission parameters will be discussed and participating member institutions will carry out standardization of these techniques. Collection of air emission samples taken directly at the source, either in the exhaust stream of ventilation air from a building or at the surface of manure storage units (lagoon, basins, tanks, or pits) will be specified. Long term sampling over several hours or days vs. less expensive short duration sampling will be done (MN, IN, IA) to determine minimum levels of sampling to obtain representative emission rates from an animal production source. Minimum instrumentation and equipment requirements for emission measurement of both contaminant concentration and airflow will be established. The development of these requirements for the specific parameters include: odor (MN, IA, IN); gases (MN, IA, IN, IL, NC, OR, TX); particulates (IL, IN, MN, NC, TX); and pathogens (MN, IN, IL, NC, TX).

Airborne emission factors from animal production systems have been reported in the literature in a variety of ways from concentration or mass per area of source, per animal, or standard animal weight. The variety of ways of expressing emissions has made it difficult to compare values between studies and to compare results to federal or state air emission standards. A standard expression of emission value will be selected and used in reporting research results in the project. Also, a database of emission values has been initiated by several states for parameters like odor, H₂S, and NH₃ which will be expanded to include other contaminants; other states' data will also be included to form a national database. This database would be valuable for dispersion models that need input emission data, and would be the basis for decision tools designed to select animal housing systems and practices to lower or minimize emissions. It is expected that results of this effort will impact existing and proposed federal, state, and local regulatory standards.

The initial impact of airborne odor, dust, and gas emissions from animal production systems has typically been the creation of nuisances for nearby neighbors and communities. Site selection tools or models to assist in avoiding or minimizing these problems have been developed by several states (MN, ID, IA). These models have primarily been based on some established nuisance or annoyance threshold odor level. This project will continue to produce and refine tools that local government officials, animal producers, neighbors, and other stakeholders can use to establish science-based setbacks that address the odor or other airborne contaminant issue(s) of concern.

Another impact of airborne emissions from animal production systems has been human health. To date none of the states have used health to measurement the impact odor, gases, dust, etc have on surrounding communities. Several states (NC, MN, IA) have suggested that this be done in cooperation with medical researchers from those respectively states. The assessment of human health impacts is beyond the present funding levels by all members, but is much needed. Scientists from the project institutions and others will continue to attempt to secure funding through public health and medical researchers.

A longer term and more subtle impact of airborne emissions is the effect pollutants may have on the earth's environment. Ammonia, which animal agriculture allegedly contributes in significant quantities, has been linked to increases in acid rain and the subsequent acidification of ecosystems. Other greenhouse gases are also produced from animal production units, and allegedly contribute to global warming. A better understanding of the quantity and quality of the emissions will help researchers assess animal agriculture's ability to control and minimize these harmful effects on our planet's ecosystems.

Control technologies to reduce airborne emissions from animal production systems are being developed and implemented for site-specific operation throughout the United States. Evaluation of these technologies will be done in the laboratory as well as under field conditions. From the animal buildings sources, technologies that reduce emissions include biofiltration, vegetable oil sprinkling, dust removal treatment, ozonation, nonthermal plasma destruction of gases, wet scrubbers and washing walls for dust and gases, and windbreak walls for dust and odor removal (MN, IL, IN, IA, NC, TX). For manure storage unit sources, emission control technologies include permeable (straw, geotextile, floating clay particles) and impermeable (rigid, flexible, and inflatable) covers, anaerobic digestion of manure, biological and chemical additives, and aerobic digestion (AL, FL, CA, MN, IL, OR, NC, IA, IN, IL). Another source of emissions is open yards/feedlots where dust and odor control technologies like water sprinkling, and manure management practices will be compared for their effectiveness in controlling emissions (TX, CA, FL). All control technologies will be evaluated not only for effectiveness or efficiency but also for management requirements and economics, so that they can be adopted by a large sector of the animal industry.

• Objective 4. Develop and evaluate feeding systems for their potential to alter the excretion of environmentally-sensitive nutrients by livestock.

Feeding strategies will be investigated at a number of participating locations to develop nutritional regimens that result in improved utilization of dietary nutrients with a concurrent reduction in excretion in nutrients of environmental concern. Much of the planned work focuses on improved P nutrition of livestock. Participating states include KY, VA, IA, GA, MN, and IN. Researchers in TN will investigate excretion of non-nutrient pollutants in manure. The shared results of each state's efforts will be used by the project participants to establish priority areas of research and outreach on an annual basis and to develop collaborative strategies to accomplish goals.

Experiments will be conducted in KY to assess the effects of feeding low-phytate corn and low-phytate soybean meal without and with added microbial phytase on the bioavailability of phosphorus in the corn and soybean meal and on phosphorus excretion from pigs and chickens. In the pig study, a low phosphorus dextrose-casein basal diet will be fed. In addition, similar diets with graded levels of phosphorus from a highly available source, monocalcium phosphate, or graded levels of phosphorus from the two types of corn and soybean meal will be fed. Another series of diets will include the two corn and soybean meal types with added microbial phytase. Similar experiments will be conducted with chicks. In IN swine studies will focus on the efficacy of phytate-phosphorus utilization when wheat bran (containing appreciable amounts of phytase activity) is included in diets. The additional fiber contribution from wheat bran is proposed to have secondary effects of odor reduction as well. Subsequent studies will assess phosphorus excretion when these two types of feedstuffs are used in practical corn-soybean meal diets.

IA and IN will investigate phytase alternatives, such as citric acid and 25-OH cholicalciferol for nonruminants. An 8-wk screening study will be conducted in IA to assess 11 dietary swine treatments that include 4 levels of non-phytate P with and without microbial phytase and/or citric acid and/or 25-OH cholicalciferol. Fecal and urine samples will be collected for P (total and phytate) analyses. Based on the results, a follow up study will assess the effects of the most promising treatment combinations on long term feeding. Weaned pigs will be fed dietary treatments to market weight. Retention of P and bone strength data will be collected. Optimal combinations of enzymes and additives will be developed for different combinations of feedstuffs (corn, soybean meal, wheat, barley, canola meal, etc.) with the GIT simulation assay. In vivo studies with chicks and poults will be used to verify results. The contribution of intestinal phytase to phytate-P hydrolysis and P retention will be also be evaluated. Nutritional and genetic factors contributing to intestinal phytase expression will be investigated in the broiler, turkey poult, and duckling. Studies are planned in IN to investigate the additive effects of microbial phytase, 25-hydroxycholecalciferol, and citric acid in diets for turkeys (similar in scope to swine trials being conducted in IA). An experiment will be conducted with turkey poults to determine the additive effects of plant and fungal phytase on the liberation and utilization of P from phytic acid. An experiment will be conducted to determine the optimal level of fungal mycelium from the commercial production of citric acid on the liberation and utilization of P from phytic acid in diets for turkey poults. A final experiment will validate the extent of P sparing by the plant phytase and fungal mycelium when used alone and in combination with turkeys raised in floor pens from 0 to 18 weeks of age. Additional studies are planned in IN to look at effects of the current industry practice of feeding pharmacological doses of copper sulfate (broilers and turkeys) and zinc oxide (pigs) on the efficacy of commercial phytases. Future studies in swine, broilers, and turkeys will focus on life-time mass balance of N, P, Ca, Zn, and Cu and implementing strategies to maximize their retention/minimize excretion.

Further processing of feed grains by removing the germ from the seed through dry milling has been used commercially for subsequent extraction of corn oil from the germ. As the phytate-phosphorus content of corn is primarily within the germ, the phosphorus content of the degermed-debranned corn (DDCORN) is greatly reduced as compared with normal corn. Studies in IN will evaluate the effects of feeding DDCORN to broiler chicks on phosphorus excretion and solubility when compared to normal corn and other feeding strategies to reduce litter phosphorus. If sufficient DDCORN can be obtained, subsequent swine, dairy and beef cattle studies will be conducted. As the DDCORN ingredient contains significantly less phytate phosphorus, expectations are that the total and soluble phosphorus content of litter from birds fed this treatment will be much lower than those fed the other diets.

Studies will be conducted in MN to determine the long term effects of feeding low inorganic phosphorus and low protein diets with a source of non-starch polysaccharide with enzyme cocktails on the performance of sows over multiple parities. Digestibility studies will be conducted during gestation and lactation to determine nutrient utilization. The impact of the feeding regimens on the performance of pigs weaned from the experimental sows will be evaluated. The characteristics of manure from both the sows and the weaned to finished pigs will be determined. This is a collaborative study with the Departments of Animal Science Biosystems and Ag. Engineering, Microbiology and Soil, Water and Climate. In conjunction with these studies, researchers in GA are looking at amino acid and phytase diets for sows. In addition to P, they are also investigating methods for reducing the Cu and Zn excretion of nursery and grow-finish pigs.

Strategies for beef cows will be explored by a number of states with VA and IN leading the efforts. In VA, experiments will be with steers fed high roughage diets to gain 0.5 to 0.75 kg/day in individual stalls in dry lot. In the initial experiment, three levels of P and two levels of available energy will be fed. The cattle will be weighed at 2-wk intervals, and blood P will be determined at 4-wk intervals. A metabolism trial will be conducted with lambs to compare organic and inorganic P utilization in ruminants, compare utilization of different organic P sources, and determine the efficacy of phytase supplementation to ruminants fed organic P. Criteria to evaluate the efficiency of P utilization will include P balance, blood serum P, bone ash and bone breaking strength. Beef steers will be used in IN to determine the benefits of using highly available phosphorus soybeans (HAPSM)/normal corn (C); highly available phosphorus corn (HAPC)/normal soybean meal (SBM); HAPSM/HAPC compared to the control normal SBM/C. Nutrient balance trials will be used to determine manure volume, nutrient retention, and nutrient excretion of N and P.

Efforts to reduce P excretion from dairy cows will be led by IA and IN. In IA, ruminal phytase activity in transition dairy cows will be assessed using in vitro procedures and commercial diets with and without additional phytate P. Supplementation with microbial phytase will also be investigated. Phytase activity of high producing dairy cows with high rates of passage will be investigated in IA by using cows with post-ruminal and post-intestinal canulas. Similarly, in IN six ruminaly cannulated lactating cows will be used to determine the extent of rumen phosphorus availability of feeds commonly fed to dairy cattle in the mid-west US, the effect of phytase feeding on phosphorus release from feeds in the rumen and the potential of phytase to release P from postruminal digesta.

Hormonal pollution of the environment, by compounds such as the potent 17$ -estradiol (17$ E), has been implicated in human and wildlife health problems. However, little is known regarding the environmental impact of hormones of animal origin. Such knowledge is timely, since current animal waste regulations are driven solely by concerns about nutrients (notably P and N), pathogens, and organic matter, with no consideration given to the impact of these regulations on environmental estrogen loads. Previous work examining livestock 17$ E discharges have focused on poultry waste; little has been reported regarding the potentially large environmental loadings of estrogen from dairy and swine operations. To address this gap in knowledge, researchers in TN will pursue the following four objectives:

First, quantify the conservation of estrogens 17$ -estradiol and estrone in full-scale dairy waste storage systems. Specifically, compare lagoons and dry-stacks for their ability to conserve applied estrogen loads. Second, measure 17$ -estradiol and estrone concentrations in runoff and leachate from plots fertilized with liquid dairy wastes. Third, determine the efficacy of high-rate anaerobic digestion for degrading 17$ -estradiol and estrone. Fourth, determine the fate of 17$ E in dry stacks, lagoons, high-rate anaerobic digesters, and soil. Specifically, use radiolabeled 17$ -estradiol in lab studies to establish the extent to which microbes in these systems can mineralize 17$ -estradiol.

Because of increasing concerns about pathogens in animal waste, scientists in TN will evaluate the occurrence of Listeria spp., Salmonella spp. and E. coli O157:H7 in a dairy farm animal waste operation, and in a stream adjacent to the production facility over a six month period. Preliminary results show that feed grain, silage and bulk milk at the experiment site frequently tested positive for both Salmonella and Listeria, while Salmonella, Listeria and E. coli O157:H7 were isolated from the waste stream (separator liquid, separator solids, holding pond liquid), stream water 3 km upstream of the farm, and stream water 1 km downstream from the farm. Pathogens are isolated and confirmed using FDA BAM protocols (enrichment). Preliminary results show that other sources impact stream quality even before the stream reaches the dairy farm, and that the potential cycling of pathogens through the production system must be carefully evaluated.