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United States Department of Agriculture

Agricultural Research Service

2008 Annual Report

1a.Objectives (from AD-416)
Objective 1 - Determine the influences of diet composition on odor compound, nitrogen, and greenhouse gas emission from manure in beef cattle and swine confinement facilities. Objective 2 - Define the beef cattle feedlot surface conditions affecting microbial activities that minimize the environmental impact of animal manure. Objective 3 - Develop strategies and technologies to reduce ammonia and odor emissions from beef cattle and swine confinement facilities

1b.Approach (from AD-416)
Objective 1 - The hypothesis to be tested is starch, nonstarch carbohydrate, and protein excretion in manure differ by diet, and these compounds are differentially utilized by microorganisms to produce malodorous compounds, ammonia, and greenhouse gases. Multiple experiments will evaluate swine and cattle manure from diets differing in starch, fiber, and crude protein contents from diverse feed sources in order to determine the effects that diet has on.
1)odor compound production and emission,.
2)nitrogen transformation and loss, and.
3)greenhouse gas emission. Manure slurries and soil/manure mixtures mimicking feedlot surfaces will be incubated over time at ambient temperature and analyzed for microbial fermentation products including straight and branched chain volatile fatty acids, aromatic, sulfur-containing, and nitrogenous compounds, alcohols, and the greenhouse gases-methane, carbon dioxide, and nitrous oxide. Follow-up field studies will seek to validate results from the laboratory by monitoring the production and emission of compounds of concern from the production environment. Objective 2 - The hypothesis to be tested is moisture content, the ratio of manure to soil, and the temperature of the feedlot surface are the dominant factors that contribute to an anaerobic microbial environment on the feedlot surface, which produces more offensive odor compounds, enhances detrimental nitrogen transformations, and contributes to greater greenhouse gas production than an inactive or aerobic microbial state. The approach will be to evaluate a range of environmental conditions affecting dominant microbial physiologies (inactive, aerobic, and anaerobic) in multiple manure and soil incubations which vary the manure moisture content, manure to soil content, and temperature. Conditions favoring beneficial microbial activities (N immobilization, odor compound consumption, and nitrification/denitrification) relative to unfavorable activities (ammonia production and emission, odor compound production and accumulation, and greenhouse gas emission) will be targeted for further characterization and ultimately evaluated in field experiments. Objective 3 - The hypothesis to be tested is a combination of plant essential oils and urease inhibitors will limit microbial activities in stored cattle and swine manure that lead to odor compound production, ammonia formation, and greenhouse gas emissions. Once an effective compound, both in least cost and inhibiting properties is selected, it will be evaluated in the laboratory with a urease inhibitor for control of ammonia and odor emissions. This combination of the urease inhibitor and plant oil will also be incorporated into a granule material. The granule will be evaluated in the laboratory for effectiveness in releasing the chemicals from the granule by quantifying volatile fatty acids, urea, and ammonia in cattle manure slurries. Field studies in a cattle feedlot will be conducted with the granule containing the two chemicals. Field studies in an anaerobic deep pit swine production facility without the granule will also be conducted.

3.Progress Report
Ethanol production from corn has resulted in a large quantity of wet distillers grains with solubles (WDGS) which has proven to be a viable feed resource for beef cattle. When these concentrated nutrients are fed as WDGS to cattle in place of corn, it often results in a diet with protein, oil, and minerals such as phosphorus and sulfur in excess of dietary needs and can potentially cause environmental pollution. A study was conducted to compare odorants and persistence of generic E. coli and E. coli O157:H7 in manure slurries stored from 0 to 28 days from cattle fed 0, 20, 40, or 60% WDGS. The results indicated all the major odorants in the manures analyzed significantly increased as the concentration of WDGS increased in the diet. It is concluded that WDGS can increase environmental pollution. NP 206 - Manure and Byproduct Utilization Action Plan, Component 1: Atmospheric Emissions, Statement-Control Technologies and Stragegies for Emissions and Component 2:Nutrient Management, Statement-1 Animal Feeding and Mgmt. Preserving urea can increase the nitrogen retention in manure and minimize ammonia emissions. Urease inhibitors can increase nitrogen content on feedlot surfaces. A study was initiated to determine the effects of urine, a urease inhibitor, N- (n-butyl) thiophosphoric triamide (NBPT), and an odor-reducing compound (thymol), on zoonotic pathogens in swine manure slurries. It is concluded manure amendments that prevent urea hydrolysis (NBPT) may promote pathogen viability. Additional treatments with antimicrobials (thymol) may be required to kill pathogens when urease inhibitors are used. NP 206: Manure and Byproduct Utilization; Component:Atmospheric Emissions, statement 3-Control Technologies and Strategies for Emissions; Component:Nutrient Mgmt, statement 2-Innovative Tech. for Collection, Storage, and treatment.

Previous research in deep-bedded dairy facilities demonstrated carbon dioxide, methane, and nitrous oxide emissions can be influenced by the use of organic bedding materials. Use of organic bedding materials in swine and dairy facilities has been shown to increase ammonia emissions compared to no bedding but no research has been conducted to evaluate gas and odor emissions in deep-bedded beef feedlot facilities. Air samples have been collected at two commercial deep-bedded monoslope barns in NW Iowa. Environmental and management factors are recorded and correlated to gas measurements. Data collection will continue at 6 week intervals through March 2009. The data collected from this project will be the first of its kind and will help quantify ammonia and greenhouse gas emissions in deep-bedded cattle confinement facilities. Ultimately, this data will provide information necessary to assist producers in managing deep-bedded cattle monoslope barns to lower odor and greenhouse gas emissions. NP 206-Manure and Byproduct Utilization Action Plan; Component 1-Atmospheric Emissions, statement 3-Control Technologies and Strategies for Emissions.

1. Odorant production from cattle fed distillers grains. A feeding trial was conducted with crossbred steers (n = 160; 434 kg) that were fed a finishing diet that contained either 0, 20, 40, or 60% wet distillers grains with solubles (WDGS), a byproduct of ethanol production from corn. The objectives were to determine what effect WDGS would have on odorants, phosphorus, nitrogen, and generic Escherichia coli concentrations in cattle manure slurries. When WDGS is fed to cattle in place of corn, crude protein and minerals often exceed dietary needs. This may increase nitrogen emission, phosphorus run-off, and odor production. Overall, this is what was observed. As the level of WDGS increased in the diet, many of the odorants in the form of volatile fatty acids and aromatic compounds increased in the manure slurries, as did ammonia and hydrogen sulfide. Total nitrogen, phosphorus, and sulfur were all found in higher concentrations in the slurries as the level of WDGS increased in the diet. Therefore, the potential for environmental pollution including elevated ammonia and odor emissions, and increased phosphorus in run-off is greater as the level of WDGS increases in the diet. These studies also indicated that feeding WDGS can extend the persistence of E. coli in manure slurries.

This accomplishment aligns with NP206, Manure and Byproduct Utilization, and specifically addresses Component 1 (Atmospheric Emissions) with emphasis in Focus Area 3 (Control Technologies and Strategies for Emissions).

2. Evaluation of wet distillers grains with solubles in feedlot cattle diets

Wet distillers grains with solubles (WDGS) are a commonly fed ingredient in feedlot diets. This feedstuff has high concentrations of nitrogen (N), sulfur (S), and phosphorus (P), which may contribute to odor production and nutrient excretion from cattle manure. The high fiber content of WDGS may contribute to methane during digestion and affect the animal’s ability to utilize energy for growth. A study was conducted to determine the effects of feedlot cattle diets containing 0, 20, 40, or 60% WDGS on energy retention, methane production, and N, S, and P excretion. Methane production decreased when WDGS was added to the diet. However, energy retention decreased as the level of WDGS increased in the diet. This indicates that finishing cattle fed increasing levels of WDGS in the diet have decreased efficiency of energy utilization which could lead to decreased performance in the feedlot. Cattle fed WDGS may also have increased odor production and P run off from manure when WDGS is fed at levels above 40% of the diet dry matter.

This accomplishment aligns with NP206, Manure and Byproduct Utilization, and specifically addresses Component 1 (Atmospheric Emissions) with emphasis in Focus Area 3 (Control Technologies and Strategies for Emissions).

5.Significant Activities that Support Special Target Populations

6.Technology Transfer

Number of Non-Peer Reviewed Presentations and Proceedings3

Review Publications
Wells, J., Varel, V.H. 2008. Viability of zoonotic pathogens Escherichia coli and Salmonella in swine manure slurries with and without a urease inhibitor and thymol. Letters in Applied Microbiology 46:477-482.

Animut, G., Puchala, R., Goetsch, A.L., Patra, A.K., Sahlu, T., Varel, V.H., Wells, J. 2008. Methane emission by goats consuming diets with different levels of condensed tannins from lespedeza. Animal Feed Science and Technology 144:212-227.

Animut, G., Puchala, R., Goetsch, A.L., Patra, A.K., Sahlu, T., Varel, V.H., Wells, J. 2008. Methane emission by goats consuming different sources of condensed tannins. Animal Feed Science and Technology 144:228-241.

Last Modified: 4/22/2015
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