2007 Annual Report 1a.Objectives (from AD-416) 1. Livestock Feeding: Evaluate animal nutrition regimens that decrease losses of feed nutrients in manure, decrease ammonia emissions, decrease particulate matter emissions, decrease excretion of pathogens, improve the value of cattle manures for land application, maintain animal productivity, and minimize risks to the environment, livestock and the public. Determine the impact on livestock performance and environmental quality of the following characteristics of distiller's grain: high concentrations of phosphorus and sulfur, changing composition due to removal of fats and other constituents, and concentration of antibiotics used in the fermentation process. 2. Feedyard/Manure Management: Evaluate feedyard and manure management regimens that decrease losses of feed nutrients to the environment, decrease ammonia emissions, decrease particulate matter emissions, decrease pathogen loads and pharmaceutically active compounds, improve the value of cattle manures for land application, maintain productivity, and reduce impacts on the environment, livestock, and the public. 3. Feedyard and Dairy Emissions, Losses and Accumulation: Quantify atmospheric emissions, runoff losses, and accumulation of nutrients, bioaerosols, pathogens, and pharmaceutically active compounds; determine their fate and transport; determine the distribution of virulence factors and antibiotic resistance of key pathogens; and evaluate their potential risk to livestock, crops, the public, and the environment. 4. Land Application: Determine land application protocols that decrease atmospheric emissions of ammonia, particulates and pathogens and minimize their impact on the environment, crops, the public, and livestock. 1b.Approach (from AD-416) Experimental objectives are accomplished through a combination of cooperative, multidisciplinary studies that extend from basic laboratory scale experiments to practical field experiments. Lab-scale and research feedlot-scale studies are used to determine how chemical, physical and microbiological factors affect nutrient losses and pathogen excretion and for initial evaluation of potential control measures. Larger field studies will be used to determine the production, fate, and transport of potential pollutants and pathogens under practical conditions in the southern Great Plains of the U.S. 4.Accomplishments AMMONIA EMISSIONS FROM A COMMERCIAL BEEF CATTLE FEEDYARD: Ammonia emitted from beef cattle feedyards represents a loss of nitrogen and fertilizer value from manure and can negatively impact the environment locally and regionally. ARS researchers from the Conservation and Production Research Laboratory, Bushland, Texas, in collaboration with researchers from the University of Alberta, Edmonton, Canada, and the University of Georgia, Athens, used an inverse dispersion model and a database of atmospheric ammonia concentration and wind and temperature profiles collected on 39 days during five months over three years to quantify ammonia emissions from a beef cattle feedyard Mean summer emission rate was 7420 kg NH3 d-1, and winter emission rate was about half that, at 3330 kg NH3 d-1. Annual NH3-N emission rate was 4430 kg NH3-N d-1, which was 53% of the N fed to cattle. These are the most comprehensive measurements of feedlot ammonia emissions currently available for use by scientists, the cattle industry, and regulators, and will lead to a better understanding of ammonia emission from High Plains feedyards, will allow emission models/factors to be developed based over a wide range of seasonal and environmental conditions, and will potentially lead to more accurate, scientifically determined ammonia emission rates. (NP206, Atmospheric Emissions Component; Problem Area 2, Emission Factors from Livestock Facilities) PATHOGENS OF DAIRY WASTEWATER: Wastewater in many Southern High Plains dairies is reused for floor flushing or other purposes; however, the pathogen and toxin content of this water is unknown. Wastewater flows from the origin to its final use in a center-pivot irrigation system were sampled at four southern plains dairies by an ARS veterinary microbiologist from the Conservation and Production Research Laboratory, Bushland, Texas, during summer and winter and analyzed for pathogens and total concentrations of bacteria, yeast, fungi, and endotoxin. Dairy wastewater contained a large diverse group of Salmonella, and high concentrations of endotoxin; however, concentrations differed among seasons. This information could potentially be important in evaluating best management practices for the reuse of wastewater at dairies. (NP206, Pathogens and Pharmaceutically Active Compounds Component; Problem Area 2, Fate and Transport of Pathogens) EFFECT OF DIETS ON FECAL MICROBIAL COMMUNITY STRUCTURE AND FECAL SHEDDING OF E. COLI O157:H7 IN CATTLE: Increased emphasis is being placed on the production of ethanol from grain sources; however, little is known about the potential effect of feeding distiller's grains (DG) based diets on the fecal shedding of pathogens. Fecal samples obtained from two beef cattle feeding trials involving DG were characterized for both broad scale shifts in microbial community structure and fecal shedding of E. coli O157:H7. Both studies indicate that bovine fecal microbiota community structure is significantly affected by DG and that there is a possible increase in the fecal shedding of E. coli O157:H7 from animals fed sorghum-based DG when compared to control and corn-based DG diets. Sensitive methods (qPCR) to evaluate E. coli O157:H7 loads in manure were developed, and data suggests a variable distribution of E. coli O157:H7 (approximately 35% positive) within manure samples and that these mixtures contain from 10 to 100,000 copies of E. coli O157:H7 per gram of manure. These results suggest a different underlying mechanism (other than acid fermentative selection for E. coli O157:H7) is involved in elevated population levels of E. coli O157:H7 in cattle fed high concentrate diets and that this elevation of E. coli O157:H7 levels may be due to altered microbial community structure that we have observed. Identification of this new pathway will allow for evaluation of management strategies to reduce fecal shedding of E. coli O157:H7 and ensuring a safer food supply. (NP206, Pathogens and Pharmaceutically Active Compounds Component; Problem Area 2, Fate and Transport of Pathogens) EFFECTS OF ZEOLITE AND FAT ON AMMONIA EMISSIONS: Economically viable methods to decrease ammonia emissions from concentrated animal feeding operations may be needed in the future. Using a lab-scale system, ARS researchers at the Conservation and Production Research Laboratory, Bushland, Texas, conducted a series of studies to determine the effects of zeolites and fat on ammonia emissions from simulated feedlot surfaces. Applications of zeolite or corn oil directly to the pen surface decreased emissions by more than 50%, however, when fed to beef steers they did not affect ammonia emissions. These results demonstrate that zeolites and fat have the potential to decrease ammonia emissions from feedlot pen surfaces but additional research is required to optimize the effects. (NP206, Atmospheric Emissions Component; Problem Area 2, Emission Factors from Livestock Facilities) FEEDING DISTILLER'S GRAINS TO BEEF CATTLE, DAIRY CATTLE, AND SWINE: Distiller's grains, a by-product of the production of ethanol from feed grains, can serve as feeds for livestock; however, most of the research on feeding distiller's grains is with corn-based, rather than sorghum-based products, the anticipated major grain source to be used in the new bioethanol plants constructed in the southern Great Plains. At the Conservation and Production Research Laboratory, Bushland, Texas, Specific Cooperative Agreements were developed with Kansas State University, Manhattan, Kansas; Texas Tech University, Lubbock, Texas; West Texas A&M University, Canyon, Texas; the University of Minnesota, Minneapolis/St. Paul, Minnesota; and the Texas Agricultural Experiment Station in Amarillo, Texas, to conduct cooperative research studies on the use of grain sorghum-based distiller’s grains in diets for finishing beef cattle, dairy cows, and swine. Results of these experiments demonstrate that distiller’s grains have less value in typical Southern Great Plains feedlot diets that contain steam-flaked corn and fat than in typical Northern Great Plains diets than contain dry-rolled corn and no added fat. Additional details are available in progress reports of subordinate projects. (NP206, Byproducts Component; Problem Area 1, Phytoavailability and Bioavailability of Nutrients, Trace Elements and Xenobiotics in Byproducts Considered for Beneficial Use) CONTINUOUS MONITORING OF AMMONIA EMISSIONS FROM TWO BEEF CATTLE FEEDYARDS: Long-term monitoring of ammonia emissions from feedyards is needed to better understand seasonal patterns and variability and the factors that affect emissions. ARS researchers from the Conservation and Production Research Laboratory, Bushland, Texas, developed and deployed ammonia emissions monitoring systems at two commercial beef cattle feedyards and measured atmospheric ammonia concentrations and critical meteorological variables continuously for eleven months. The resulting databases will allow detailed analysis of year-round ammonia emissions, process-based model validation, and development of emission factors. (NP206, Atmospheric Emissions Component; Problem Area 1, Understanding the Biological, Chemical, and Physical Mechanisms Affecting Emissions, and Problem Area 2, Emission Factors from Livestock Facilities) FINE DUST EXPOSURE INCREASES THE SPEED OF RESPIRATORY FUNGAL PATHOGENESIS: The effects of feedyard dust on the incidence and severity of respiratory disease in ruminants is not known. An ARS microbiologist at the Conservation and Production Research Laboratory, Bushland, Texas, in collaboration with the Texas Tech Health Sciences Center in Lubbock, Texas, conducted an experiment to study the effects of feedyard dust inhalation on fungal pathogenesis in non-immunosuppressed goats. Goats pretreated with high concentrations of fine dust aerosols and goats not pretreated with dust were challenged to induce fungal respiratory disease. Prolonged exposure to high concentrations of fine dust appeared to increase the speed of induced fungal respiratory disease, increased the severity of induced lung fibrosis, and increased the quantity of fungal spores in the lung lesions. These results suggest that fine dust particles may potentially increase the incidence and severity of respiratory disease in ruminants by decreasing the efficiency of the phagocytic immune system. (NP206, Pathogens and Pharmaceutically Active Compounds Component; Problem Area 2, Fate and Transport of Pathogens) ATMOSPHERIC PATHOGENS AND ENDOTOXINS IN DAIRIES: Pathogen and endotoxin content of ambient outside air and inside air of milking parlors at dairies have not been studied extensively. An ARS microbiologist at the Conservation and Production Research Laboratory, Bushland, Texas, in collaboration with Texas Tech Health Sciences Center in Lubbock, Texas, conducted a study to evaluate the concentration and identification of bioaerosols during summer and winter at the boundary fences, commodity barn, compost windrow fields, and inside the milking parlor of four large dairies on the Southern Great Plains. Both Gram-negative and Gram-positive bacterial pathogens of animal- and human-origin and endotoxins were identified in the aerosols. Average endotoxin concentrations were similar in summer and winter (415 vs. 313 micrograms/cubic meter, respectively). These results may impact recommendations for dairy barn ventilation and future bioaerosol standards. (NP206, Pathogens and Pharmaceutically Active Compounds Component; Problem Area 2, Fate and Transport of Pathogens) EFFECT OF FFEDLOT PEN SURFACE LAYERS ON MICROBIAL COMMUNITY STRUCTURE: Factors controlling the generation of ammonia, greenhouse gases, and the cycling of N by microorganism in feedlot layers is not clearly understood. Scientists at the Conservation and Production Research Laboratory, Bushland, Texas, studied the microbial community structure associated with the various feedlot pen surface layers. Research results indicated that different lineages of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria are present in the various physical layers, and that these groups of organisms are important for the cycling of N. Feedlot pen surface experiments also suggest that urine and moisture levels are important in the maintenance of ammonia-generating bacteria. Knowledge of this microbial community structure will help in the evaluation of different management strategies to reduce the loss of N from feedyards. (NP206: Atmospheric Emissions Component; Problem Area 1, Understanding the Biological, Chemical, and Physical Mechanisms Affecting Emissions) AMMONIA LOSSES FROM URINE SPOTS: Ammonia emitted from beef cattle feedyards represents a loss of nitrogen and fertilizer value from manure and can negatively impact the environment locally and regionally. ARS researchers from the Conservation and Production Research Laboratory, Bushland, Texas, conducted a study at the USDA-ARS experimental feedlot to determine the effects of urine and simulated rainfall on the chemistry of the feedlot pen surface during the summer and winter. Following the application of artificial cattle urine to experimental plots of feedlot pen surfaces, the pH of the surface increased rapidly and the ammonium concentration of the surface increased an order of magnitude in less than 5 minutes and remained elevated for 24 to 72 hours; the decrease in ammonium concentrations was more rapid in the winter than in the summer. These results demonstrate that loss of ammonia from the feedlot surface occurs rapidly from urine spots even during the winter, and thus, to be effective, methods to control ammonia losses must be present on the pen surface or in the urine, and that experimental methods that do not take into account this rapid ammonia loss and spatial variability will greatly underestimate ammonia emissions from feedlot pens. (NP206, Atmospheric Emissions Component; Problem Area 1, Understanding the Biological, Chemical, and Physical Mechanisms Affecting Emissions) EFFECT OF SYTHETIC URINE AND MOISTURE CONTENT ON MICROBIAL COMMUNITY STRUCTURE AND PERSISTENCE OF E COLI O157:H7 ON FEEDLOT PEN SURFACES: The role of cattle urine, feces, and microorganisms in the production of ammonia and the persistence of pathogens is poorly understood. Application of synthetic urine and water to feedlot pen surfaces was shown to alter microbial community structure. Application of water apparently aided in the release of existing nutrients for utilization and growth of existing microbes; whereas, application of synthetic urine (nutrient plus moisture) apparently released existing nutrients and also supplied new nutrients (i.e., urea) for the growth of microorganisms, resulting in shifts in the microbial community structure. This research also suggests that significant quantities of preexisting microbially derived urease enzymes may be present in the feedlot pen surface and be responsible for the immediate production of ammonia that was observed upon the addition of moisture, and that E. coli O157:H7 is capable of long-term survival in manure-soil mixtures (weeks to months). This knowledge may be useful in evaluating management strategies to reduce both the generation of ammonia and fecal population levels of E. coli O157:H7. (NP206, Pathogens and Pharmaceutically Active Compounds Component; Problem Area 2, Fate and Transport of Pathogens; and NP206, Atmospheric Emissions Component; Problem Area 1, Understanding the Biological, Chemical, and Physical Mechanisms Affecting Emissions) PM DUST PARTICLES IN DAIRIES: The size and concentration of dust particles in the air of feedyards and dairies on the Southern High Plains is not well documented. An ARS microbiologist at the Conservation and Production Research Laboratory, Bushland, Texas, conducted a study to evaluate particulate matter concentrations of the ambient air during the summer and winter at the boundary fences, commodity barn, compost windrow fields, and inside the milking parlor of four large dairies for eight consecutive days at each dairy. Concentrations of PM2.5, coarse inhalable PM, and PM10 particulates were greater in winter than in summer but were greater inside, than outside, the milking parlor, possibly due to fine PM produced by heaters within the milking parlor. Results indicated that during most sampling events the dairies studied were in compliance with EPA regulations for PM2.5 and PM10. (NP206, Atmospheric Emissions Component; Problem Area 2, Emission Factors from Livestock Facilities) EFFECTS OF AIR EXCHANGE RATE ON AMMONIA LOSSES FROM FLUX CHAMBERS: Flux chambers are often used to measure ammonia emissions from pen and retention pond surfaces at livestock feeding operations; however, because of large spatial variability in ammonia emissions and the effects of flux chambers on the microenvironment of the surface, values obtained using flux chambers may differ greatly from true values. ARS researchers from the Conservation and Production Research Laboratory, Bushland, Texas, conducted a study to determine the effects of air exchange rate on ammonia emissions measured from a simulated retention pond or feedlot pen surface (i.e., cellulose) with three ammonia emission potentials. With air exchange rates of 4 turnovers per minute or less, measured ammonia flux was 50% or less of the flux from surfaces with no chamber, and at exchange rates of 2 per minute or less differences in treatments could not be measured accurately. Because of large spatial variability, the number of samples required to obtain repeatable estimates of ammonia flux from the pen surface was essentially unattainable. These results demonstrate that flux chambers are not appropriate to obtain accurate estimates of true ammonia flux from retention ponds or pen surfaces and that chambers with low air exchange rates may be inappropriate to test treatment differences. (NP206, Atmospheric Emissions Component; Problem Area 2, Emission Factors from Livestock Facilities) HORMONES IN FEEDYARD WASTEWATER SHALLOW LAKES (PLAYAS) AND DAIRY LAGOONS: The hormone content of feedyard wastewater has not been studied extensively. An ARS microbiologist at the Conservation and Production Research Laboratory, Bushland, Texas, in collaboration with scientists at the Texas Tech Health Sciences Center in Lubbock, Texas, measured the concentrations of three endogenous hormones (17-beta-estradiol, testosterone, and cortisol) in runoff retention ponds at seven large feedyards, lagoons at four large dairies, and three non-feedyard control playas on the Southern High Plains by radioimmunoassay. In general, hormone concentrations in feedyard playas and dairy lagoons were higher than in non-feedyard playas, with dairy lagoon concentrations being higher in winter than in summer. Because of location, underlying soil/clay composition, and lagoon liners, hormones in feedyard retention ponds or dairy lagoons do not appear to be a hazard to mammals, surface water, or ground water; however, the potential for effects on waterfowl that may frequent them is unknown. (NP206, Pathogens and Pharmaceutically Active Compounds Component; Problem Area 3, Pharmaceutically Active Compounds (PACs)) DRY DEPOSITION OF AMMONIA: Ammonia emitted from beef cattle feedyards can be deposited downwind, potentially affecting sensitive ecosystems and emission estimates. ARS researchers from the Conservation and Production Research Laboratory, Bushland, Texas, and a graduate student from West Texas A&M University, Canyon, Texas, attempted to measure dry deposition of ammonia downwind of a feedyard using micrometeorological methods and three surrogate surfaces. Dry deposition measured using soil as the surrogate surface was 10 times greater than with glass beads or nylon screen, suggesting most of the dry deposition occurred in dust particles. Ammonia profiles downwind of the feedyard were erratic, making measurements of dry deposition difficult or impossible via micrometeorological methods. These results will help to more completely understand the dynamics and environmental impacts of ammonia emissions from concentrated animal feeding operations. (NP206, Atmospheric Emissions Component; Problem Area 2, Emission Factors from Livestock Facilities) EFFECT OF SPRINKLER DUST CONTROL ON AMMONIA EMISSIONS: Emission of dust from cattle feedyards is a persistent issue, with problems ranging from nuisance complaints from neighbors to human health concerns. Sprinkler application of water to pen surfaces can control dust, but its effect on ammonia emissions is unknown. ARS researchers from the Conservation and Production Research Laboratory, Bushland, Texas, in collaboration with scientists from Texas A&M University, College Station, Texas established long-term monitoring systems to measure ammonia and dust emissions from one feedyard without dust control and one feedyard that uses periodic water application by sprinklers to control dust. Results from this study will help to determine the interaction of dust and ammonia emissions and aid feedyard managers in developing best management practices to minimize the emissions of dust and ammonia. (NP206, Atmospheric Emissions Component; Focus Area 3, Control Technologies and Strategies for Emissions) 6.Technology Transfer Number of non-peer reviewed presentations and proceedings 20 Number of newspaper articles and other presentations for non-science audiences 5 Review Publications Vasconcelos, J.R., Greene, L.W., Cole, N.A., Brown, M.S., McCollum, F.T., Tedeschi, L. 2006. Effects of phase feeding of protein on performance, blood urea nitrogen concentration, manure n:p ratio and carcass characteristics of feedlot cattle. Journal of Animal Science. 84:3032-3038. Cole, N.A., Defoor, P., Galyean, M., Duff, G., Gleghorn, J. 2006. Effects of phase-feeding of crude protein on performance, carcass characteristics, serum urea nitrogen concentrations, and manure nitrogen of finishing beef steers. Journal of Animal Science. 84:3421-3432. Cole, N.A., Brown, M.S., Varel, V.H. 2007. Beef Cattle - Manure Management. In: Bell, A.W., Pond, W.G., editors. Encyclopedia of Animal Science. Taylor and Francis, 1(1):1-4. Archibeque, S.L., Freetly, H.C., Cole, N.A., Ferrell, C.L. 2007. The influence of oscillating dietary protein concentrations on finishing cattle. II. Nutrient retention and ammonia emissions. Journal of Animal Science. 85(6):1496-1503. Flesch, T.K., Wilson, J.D., Harper, L.A., Todd, R.W., Cole, N.A. 2007. Determining ammonia emissions from a cattle feedlot with an inverse dispersion technique. Agriculture and Forest Meteorology. 144:139-155. Purdy, C.W., Clark, R.N., Straus, D.C. 2007. Analysis of aerosolized particulates of feedyards located in the Southern High Plains of Texas. Aerosol Science and Technology. 41:497-509. Purdy, C.W., Straus, D.C., Hoover, M.D. 2007. Fever and leukocytosis responses in goats to inhaled endotoxin are dose-dependent. ScienceDirect. Small Ruminant Research. 70:140-144.