Category: Feed Management

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Predicting Manure Nitrogen and Phosphorus Characteristics of Beef Open Lot Systems

This project involves the analysis of a new data set for manure characteristics from open lot beef systems demonstrating both average characteristics and factors contribution to variability in manure characteristics among these systems. Defining the characteristics and quantities of harvested manure and runoff from open earthen lot animal systems is critical to planning storage requirements, land requirements for nutrient utilization, land application rates, and logistical issues, such as equipment and labor requirements. Accuracy of these estimates are critical to planning processes required by federal and state permitting programs. Poor estimates can lead to discharges that result in court action and fines, neighbor nuisance complaints, and surface and ground water degradation. Planning procedures have historically relied upon standard values published by NRCS (Stettler et al., 2008), MWPS (Lorimor et al., 2000), and ASABE (2014) for average characteristics.

What Did We Do?

A large data set of analyses from manure samples collected over a 15-year period from 444 independent cattle feedlot pens at a single eastern Nebraska research facility was reviewed to provide insight to the degree of variability in observed manure characteristics and to investigate the factors influencing this variability. No previous efforts to define these characteristics have included data gathered over such a wide range of dietary strategies and weather conditions. This exclusive research data set is expected to provide new insights regarding influential factors affecting characteristics of manure and runoff harvested from open lot beef systems. The objective of this paper is to share a preliminary summary of findings based upon a review of this data set.

What Have We Learned?

A review of this unique data set reveals several important preliminary observations. Standard values reported by ASABE and MWPS for beef manure characteristics in open lot systems are relatively poor indicators of the significant variability that is observed within open lot feeding systems. Our data set reveals significant differences between manure characteristics as a function of feeding period (Table 1) and substantial variability within feeding period, as illustrated by the large coefficients of variation for individual characteristics. Differences in winter and summer conditions influence the characteristics and quantities of solids, organic matter, and nutrients in the harvested manure. The timing of the feeding period has substantial influence on observed differences in nitrogen loss and nitrogen in manure (Figure 1). Nitrogen recovery for the warmer summer feeding periods averaged 51 and 6 grams/head/day in the manure and runoff, respectively, with losses estimated to be 155 grams/head/day.  Similarly, nitrogen recovery in manure and runoff for the winter feeding period was 90 and 4 grams/head/day, respectively, with losses estimated at 92 grams/head/day (Figure 1 and Koelsch, et al., 2018). In addition, differences in weather and pen conditions during and following winter and summer feeding periods impact manure moisture content and the mixing of inorganics with manure (Table 1).

Table 1. Characteristics of manure collected from 216 and 228 cattle feedlot pens during Summer and Winter feeding periods, respectively1.
University of Nebraska Feedlot in East Central Nebraska Standard Values
Summer Winter ASABE NRCS MWPS3
Mean CV2 Mean CV2 Mean Mean
Total Manure (wet basis), kg/hd/d 9.3 99% 13.1 43% 7.5 7.9
DM    % 71% 10% 63.2% 15% 67% Collected 55%
    kg/hd/d 5.4 80% 8.0 41% 5.0 manure 4.3
OM    % 24% 28% 25.3% 41% 30% is not 50%
    kg/hd/d 1.00 52% 1.87 41% 1.5 reported. 2.2
Ash    % 76% 9% 74.7% 14% 70% 50%
    kg/hd/d 4.16 72% 6.10 49% 3.5 2.2
N    % 1.3% 36% 1.19% 23% 1.18% 1.2%
    g/hd/d 51 50% 90 33% 88 95
P    % 0.37% 41% 0.34% 29% 0.50% 0.35%
    k/hd/d 17.7 55% 26.0 42% 37.5 27.7
DM = dry matter; OM = organic matter (or volatile solids)

1    Summer = April to October feeding period, Winter = November to May feeding period

2    Coefficient of variation, %

3    Unsurfaced lot in dry climate with annual manure removal.
two pie charts
Figure 1. Distribution of dietary nitrogen consumed by beef cattle among four possible ed points for summer and winter feeding periods.

Dietary concentration of nutrients was observed to influence the harvested manure P content (Figure 2) but produce minimal impact on harvested manure N content (not shown). Diet was an important predictor in observed N losses, especially during the summer feeding period. However, its limited value for predicting harvested manure N and moderate value for predicting harvesting manure P suggests that other factors such as weather and management may be influential in determining N and P recovered (Koelsch, et al., 2018).

scatter plot with trendlines
Figure 2. Influence of dietary P concentration on harvested manure P.

Significant variability exists in the quantity of total solids of manure harvested with a factor of 10 difference between the observed low and high values when compared on a mass per finished head basis (note large CVs in Table 1). This variability has significant influence on quality of the manure collected as represented by organic matter, ash content, and moisture content.

Although individual experimental trials comparing practices to increase organic matter on the feedlot surface have demonstrated some benefit to reducing nitrogen losses, the overall data set does not demonstrate value from higher pen surface organic matter for conservation of N in the manure (Koelsch, et al., 2018). However, higher organic matter manure is correlated to improved nitrogen concentration in the manure suggesting a higher value for the manure (Figure 3).

scatter plot with trendlines
Figure 3. Influence of pen surface organic matter measured as organic matter in the harvested manure) on nitrogen concentration in the manure.

It is typically recommended that manure management planning should be based upon unique analysis for manure characteristics representative of the manure being applied.  The large variability in harvested manure from open lot beef systems observed in this study further confirms the importance of this recommendation. The influence of weather on the manure and the management challenges of collecting manure from these systems adds to the complexity of predicting manure characteristics.  In addition, standard reporting methods such as ASABE should consider reporting of separate standard values based upon time of the year feeding and/or manure collection period. This review of beef manure characteristics over a 15 year period further documents the challenge of planning based upon typical or standard value for open lot beef manure.

Future Plans

The compilation and analysis of the manure and runoff data from these 444 independent measure of feedlot manure characteristics is a part of an undergraduate student research experience. Final review and analysis of this data will be completed by summer 2019 with the data published at a later time. The authors will explore the value of this data for adjusting beef manure characteristics for ASABE’s Standard (ASABE, 2014).

References

ASABE. 2014.  ASAE D384.2 MAR2005 (R2014):  Manure Production and Characteristics. ASABE, St. Joseph, Ml. 32 pages.

Koelsch, R. , G. Erickson2, M. Homolka2, M. Luebbe. 2018. redicting Manure Nitrogen, Phosphorus, and Carbon Characteristics of Beef Open Lot Systems. Presented at the 2018 ASABE Annual International Meeting. 15 pages.

Lorimor, J., W. Powers, and A. Sutton. 2000. Manure characteristics. Manure Management Systems Series MWPS-18. Midwest Plan Service. Ames Iowa: Iowa State University.

Stettler, D., C. Zuller, D. Hickman. 2008. Agricultural Waste Characteristics.  Chapter 4 of Part 651, NRCS Agricultural Waste Management Field Handbook. pages 4-1 to 4-32.

 

Authors

Richard (Rick) Koelsch, Professor of Biological Systems Engineering and Animal Science, University of Nebraska-Lincoln

rkoelsch1@unl.edu

Megan Homolka, student, and Galen Erickson Professor of Animal Science, University of Nebraska-Lincoln

Additional Information

Koelsch, R. , G. Erickson2, M. Homolka2, M. Luebbe. 2018. Predicting Manure Nitrogen, Phosphorus, and Carbon Characteristics of Beef Open Lot Systems. Presented at the 2018 ASABE Annual International Meeting. 15 pages.

 

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

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Translating Beef Production Research to Marketing Outcomes

The audience will learn about different beef production systems and their performance outcomes. Participants will have the opportunity to expound upon the information shared, inquire with panelists, and actively participate in beef marketing improvements.

Interactive Panel

Moderators

Dr. Megan Webb, Assistant Professor and Beef Production Systems Extension Specialist, University of Minnesota

Ms. Karin Schaefer, Executive Director, Minnesota Beef Council

Panelists

Ms. June Dunn, Field Specialist, Greater Omaha Packing Company

Dr. Alan Rotz, Agricultural Engineer, USDA-ARS Pasture Systems and Watershed Management

Dr. Garrett Steede, Teaching Assistant Professor, Ag. Education, Communication and Marketing, University of Minnesota

Mr. Jerry Wulf, Partner at Wulf Cattle Company

Corresponding Author

Megan Webb, University of Minnesota, mwebb@umn.edu

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

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Feed Manipulation, Manure Treatment and Sustainable Poultry Production

This study examined the effects of different treatments of poultry faecal matter on potential greenhouse gas emission and its field application and also evaluated dietary manipulation of protein on the physico-chemical quality of broiler faeces and response of these qualities to 1.5% alum (Aluminium sulphate) treatment during storage.

Poultry litters were randomly assigned to four treatments: salt solution, alum, air exclusion and the control (untreated). Chicks were allotted to corn-soy diets for 42d. The diets were 22 and 20% CP with methionine + lysine content balance and, 22 and 20% CP diets with 110% NRC recommendation of methionine and lysine.

Alum treated faeces had higher (p<0.05) nitrogen retention than other treatments. Treated faecal samples retained more moisture (p < 0.05) than control. The pH tended to be acidic in treated samples (alum, 6.03, p<0.05) and alkaline in the control (7.37, p<0.05). Mean faecal temperature was lower for alum treated faecal samples (28.58oC, p<0.05) and highest for air-tight (29.4oC, p<0.05). Nitrogen depletion rate was significant lower (p<0.05) in alum treated faecal samples. Post-storage, samples treated with alum increased substantially (≥ 46.51%) in total microbial count, while total viable count was lower (p>0.05; 2.83×106 cfu/ml) in air-tight treatment. Maize seeds planted on alum, air-excluded and control litter soils had average germination percentage range of 65–75%, 54–75% and 74-75%, respectively. In Sorghum plots, GP was 99%, and 89%, respectively for alum and air-tight treated soil 2WAP. Average maize height 21DAP was 48 cm and 23 cm for alum and air-tight treatment, respectively. Salt treated faecal samples did not support germination. Faecal pH of broiler fed low protein diets was acidic (4.76-4.80) while treatment with alum (1.5%) led to further reduction in pH (4.78 to 4.58) faecal nitrogen and organic matter compared with control faeces in a 7 days storage. Faecal minerals were generally lower. In conclusion, feeding low level of dietary protein with or without methionine and lysine supplementation in excess of requirement is a suitable mitigation for nitrogen emission and mineral excretion in broiler production. Alum treated poultry litter will mitigate further nitrogen loss in storage because it lowered nitrogen depletion rate, pH, weight, temperature and supports potential agronomic field application index.

On-farm Demonstration of the application of these results to assist farmers to produce poultry sustainably.

Further reading

https://scholar.google.com/citations?hl=en&user=NZGTKC8AAAAJ#d=gs_md_cita-d&u=%2Fcitations%3Fview_op%3Dview_citation%26hl%3Den%26user%3DNZGTKC8AAAAJ%26citation_for_view%3DNZGTKC8AAAAJ%3AW7OEmFMy1HYC%26tzom%3D-60  

*BOLU, Steven Abiodun, ADERIBIGBE, Simeon Adedeji  OLAWALE, Simon, Malomo, G. A., Olutade, S.G and Suleiman, Z.G. Department of Animal Production, University of Ilorin, Ilorin, Kwara State, Nigeria.
*Corresponding Author: Department of Animal Production, University of Ilorin, Ilorin, Kwara State, Nigeria.
Email: bolusao2002@yahoo.co.uk Phone: +234 8060240049

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

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Carbon, Water, and Land Use for Pork Production when Modifying Type and Regional Sourcing of Feed Ingredients

Providing animal protein to tomorrow’s nine billion people will be a challenge given the associated environmental pressures with animal production, particularly issues such as greenhouse gas (GHG) emissions, human health and water usage/quality. Globally, livestock production systems contribute 14.5% to the total human-induced emissions of greenhouse gases (FAO, 2013). Animal feed is a major component of these impacts with the composition of animal diets having important downstream effects (i.e. GHG emissions, animal productivity, animal health, product safety and quality and animal welfare) as well as upstream effects on water quality, GHG emissions, land use and energy consumption (Makkar, 2016). Despite these effects, feeding programs for swine largely only focus on cost minimization and productivity (Dubeau et al. 2011; Pomar et al. 2007). Finding ways to produce animal protein while reducing the environmental impacts is vital to maintaining the long-term economic viability and cultural significance of this industry.

Pork, and the meat industry in general, has downstream pressure from customers to decrease environmental impacts. Major food companies have initiated supply chain management programs to minimize their carbon footprint in response to consumer demands and societal concerns. Within pork production, feed grains and manure management are the two largest contributors to GHG emissions, water use and land use (Matlock et al., 2014; Thoma et al., 2011). However, there is high variability in agricultural production systems and the associated environmental impacts across these locations (Yang and Heijung 2016; Hellweg and Canals, 2014). There is further variability across space due to the large differences in manure management practices, climate conditions and fuel mixes employed in U.S. counties and processing facilities. While research has been done on characterizing the average environmental impacts across the U.S. (Thoma et al 2011; Macleod et al 2013), and for particular production systems on a specific farm (or on average) (Bandekar et al 2014), this substantial variability across the U.S. can significantly affect specific supply chain environmental impacts.

What did we do?

The US pork industry is not a homogenous group of producers (in location, size, or even feed inputs) and therefore providing one single LCA number for the entire industry is incomplete. To capture this variability we used the Food Systems Sustainable Supply-chain model (FoodS3) that uses county level environment impacts of corn production, rather than using a single national average estimate. We also added spatial difference in manure impacts by estimating the volatile solids excreted in manure by the three regional feeding programs using county specific manure management practices. Using these estimates, we calculated the water and land use impacts of corn feed inputs in regional pig feeding programs, as well as the GHG impacts from corn feed inputs and manure emissions. We ran these calculations for four feed programs including: 1) the use of corn distillers dried grains with solubles (DDGS) and 2) dehydrated retail level food waste, as approaches for recycling nutrients back into pig feed; as well as 3) the use of synthetic amino acids (AA) and 4) enzymes (i.e. phytase), as back-end diet supplementation strategies for minimizing the environmental impact of pork production.

What have we learned?

The inclusion of county level spatial environmental impact data and supply chain connections are significant to this work. Location matters, not just in regional diet mixes, but also in environmental impacts of sourcing ingredients and manure management. With the FoodS3 model is was possible to bring in modeled supply relationships in environmental impact analysis. Similarly, having food waste data nutrient analyses available to test a food waste diet added in a hypothetical “future technology” for pig food that has not been extensively studied.

We found that using the food waste feeding program resulted in the lowest corn input greenhouse gas emissions totals compared with all other feeding programs evaluated in this study. However, for all GHG emissions, the control feeding program had the lowest GHG emissions. While use of synthetic amino acids decreased excretion of volatile solids in manure, it resulted in the greatest greenhouse gas emissions. These emissions are the result of proportionally greater use corn in the synthetic amino acid diets than any other diet (more corn was required to ensure that the diet met the Nutrient Requirement for Swine (NRC, 2012) in our modeled diets). The impact of feeding program on greenhouse gas emissions also varied among geographic regions, where the Mid-West region had the least per pig emissions regardless of the type of diets used in the feeding program. This variation is primarily due to the spatially different emissions of feed ingredients estimated with our FoodS3 model. As expected, water and land use were least for the feeding program based on food waste, while using synthetic amino acids in diets resulted in the greatest water and land use per pig produced.

Future plans

While this study was an important step in bringing spatial heterogeneity to understanding the environmental impacts of pig diets, further work should consider diets with combinations of our alternative ingredients. Most commercially available pig diets already include synthetic AA and inorganic phosphorus (P), and many include DDGS. Furthermore, the diets may have regional variations in more than just corn and soy (which we accounted for), but also in some of our alternative ingredients, such as DDGS and food waste. Future research is needed to compare the environmental impacts of these diets to one that includes food waste as well as examine different rates of inclusion for food waste.

Authors

Jennifer Schmitt1*, Pedro Urriola2, Jae Cheol Jang3; Gerald Shurson4

1 Program Director and Lead Scientist, NorthStar Initiative for Sustainable Enterprise, Institute on the Environment, UMN jenniferschmitt@umn.edu

2 Research Assistant Professor, Department of Animal Science, UMN

3 Post-doctoral Associate Department of Animal Science, UMN

4 Professor-Swine Nutrition, Department of Animal Science, UMN

* Corresponding Author

Additional Information

Bandekar, P. et al., 2014. Life cycle analysis of swine management practices. San Francisco, Proceedings of the 9th International Conference on Life Cycle Assessment in the Agri-Food Sector.

Dubeau, F., Julien, P.-O., & Pomar, C. (2011). Formulating diets for growing pigs: economic and environmental considerations. Annals of Operations Research, 190(1), 239–269. https://doi.org/10.1007/s10479-009-0633-1

FAO. (2013). Food Wastage Footprint: Impacts on Natural Resources—Summary Report. Rome. Retrieved from http://www.fao.org/docrep/018/i3347e/i3347e.pdf

Hellweg, S. & Canals, L., 2014. Emerging approaches, challenges and opportunities in life cycle assessment. Science, 344(6188), pp. 1109-1113.

Macleod, M. et al., 2013. Greenhouse gas emissions from pig and chicken supply chains – a global life cycle assessment, Rome: Food and Agriculture Organization of the United Nations.

Matlock, M., Greg Thoma, B., Eric Boles Mansoor Leh, P., Sandefur Rusty Bautista, H., & Rick Ulrich, P. (2014). A Life Cycle Analysis of Water Use in U.S. Pork Production Comprehensive Report.

Pomar, C., Dubeau, F., Létourneau-Montminy, M.-P., Boucher, C., & Julien, P.-O. (2007). Reducing phosphorus concentration in pig diets by adding an environmental objective to the traditional feed formulation algorithm. Livestock Science, 111(1), 16–27. https://doi.org/10.1016/j.livsci.2006.11.011

Thoma, G., Nutter, D., Ulrich, R., Charles, M., Frank, J., & East, C. (2011). National Life Cycle Carbon Footprint Study for Production of US Swine, 1–75.

Yang, Y. & Heijungs, R., 2016. A general computation structure for regional life-cycle assessment. International Journal of Life Cycle Assessment, pp. 1-9.

Acknowledgements

Funding, in part, was provided by the National Pork Checkoff.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2019. Title of presentation. Waste to Worth. Minneapolis, MN. April 22-26, 2019. URL of this page. Accessed on: today’s date.

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USDA-NRCS and the National Air Quality Site Assessment Tool (NAQSAT) for Livestock and Poultry Operations

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Purpose

The National Air Quality Site Assessment Tool (NAQSAT) was developed as a first-of-its-kind tool to help producers and their advisors assess the impact of management on air emissions from livestock and poultry operations and identify areas for potential improvement related to those air emissions.

What did we do?

In 2007, several land-grant universities, with leadership from Michigan State University, began developing NAQSAT under a USDA-NRCS Conservation Innovation Grant (CIG). The initial tool included beef, dairy, swine, and poultry operations. A subsequent CIG project, with leadership from Colorado State University, made several enhancements to the tool, including adding horses to the species list. In 2015, USDA-NRCS officially adopted NAQSAT as an approved tool for evaluating air quality resource concerns at livestock and poultry operations. USDA-NRCS also contracted with Florida A&M University in 2015 to provide several regional training workshops on NAQSAT to NRCS employees. Six training workshops have been completed to date (Raleigh, NC; Modesto, CA; Elizabethtown, PA; Lincoln, NE; Richmond, VA; and Yakima, WA) with assistance from multiple NAQSAT development partners. Additionally, USDA-NRCS revised its comprehensive nutrient management plan (CNMP) policy in October 2015 to make the evaluation of air quality resource concerns mandatory as part of CNMP development.

Snippet from website of the National Air Quality Site Assessment Tool

Group photo of team in field

Zwicke in class lecturing

Zwicke and group in animal housing facility

What have we learned?

NAQSAT has proven to be a useful tool for bench-marking the air emissions impacts of current management on confinement-based livestock and poultry operations. In the training sessions, students have been able to complete NAQSAT runs on-site with the producer or producer representative via tablet or smartphone technologies. Further classroom discussion has helped to better understand the questions and answers and how the NAQSAT results can feed into the USDA-NRCS conservation planning process. Several needed enhancements and upgrades to the tool have been identified in order to more closely align the output of the tool to USDA-NRCS conservation planning needs. NAQSAT has also proven to be useful for evaluating the air quality resource concern status of an operation in relation to the CNMP development process.

Future Plans

It is anticipated that the identified needed enhancements and upgrades will be completed as funding for further NAQSAT development becomes available. Additionally, as use of NAQSAT by USDA-NRCS and our conservation planning and CNMP development partners expands, additional training and experience-building opportunities will be needed. The NAQSAT development team has great geographic coverage to assist in these additional opportunities.

Corresponding author, title, and affiliation

Greg Zwicke, Air Quality Engineer – Air Quality and Atmospheric Change Team, USDA-NRCS

Corresponding author email

greg.zwicke@ftc.usda.gov

Other authors

Greg Johnson, Air Quality and Atmospheric Change Team Leader, USDA-NRCS; Jeff Porter, Animal Nutrient and Manure Management Team Leader, USDA-NRCS; Sandy Means, Agricultural Engineer – Animal Nutrient and Manure Management Team, USDA-NRCS

Additional information

naqsat.tamu.edu

https://lpelc.org/naqsat-for-swine-and-poultry

https://lpelc.org/naqsat-for-beef-and-dairy/

Acknowledgements

C.E. Meadows Endowment, Michigan State University

Colorado Livestock Association

Colorado State University

Florida A&M University

Iowa Turkey Federation

Iowa Pork Producers

Iowa Pork Industry Center

Iowa State University

Iowa State University Experiment Station

Kansas State University

Michigan Milk Producers Association

Michigan Pork Producers Association

Michigan State University

Michigan State University Extension

National Pork Board

Nebraska Environmental Trust

Oregon State University

Penn State University

Purdue University

Texas A&M University

University of California, Davis

University of Georgia

University of Georgia Department of Poultry Science

University of Idaho

University of Maryland

University of Maryland Department of Animal and Avian Sciences

University of Minnesota

University of Missouri

University of Nebraska

USDA-ARS

Virginia Tech University

Washington State University

Western United Dairymen

Whatcom County (WA) Conservation District

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

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Planning for Resilience: Using Scenarios to Address Potential Impacts of Climate Change for the Northern Plains Beef System

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Purpose

Resiliency to weather extremes is a topic that Northern Plains farmers and ranchers are already familiar with, but now climate change is adding new uncertainties that make it difficult to know the best practices for the future. Scenario planning is a method of needs assessment that will allow Extension and beef system stakeholders to come together using the latest climate science to discover robust management options, highlight key uncertainties, prioritize Extension programming needs, and provide an open forum for discussion for this sometimes controversial topic.

Overall objectives:

1. Determine a suite of key future scenarios based on climate science that are plausible, divergent, relevant, and challenging to the beef industry.

2. Determine robust management options that address the key scenario drivers.

3. Develop a plan for Extension programming to address determined educational needs.

What did we do?

A team of researchers, Extension specialists, and educators was formed with members from University of Nebraska and South Dakota State University. They gathered the current research information on historical climate trends, projections in future climate for the region, and anticipated impacts to the beef industry. These were summarized in a series of white papers.

Three locations were selected to host two half day focus groups, representing the major production regions. A diverse group representing the beef industry of each region including feedlot managers, cow calf ranchers, diversified producers, veterinarians, bankers, NRCS personnel, and other allied industries. The first focus group started with a discussion of the participants past experiences with weather impacts. The team then provided short presentations starting with historic climate trends and projection, anticipated impacts, and uncertainties. The participants then combined critical climate drivers as axis in a 2×2 grids, each generating a set of four scenarios. They then listed impacts for each combination. The impacts boundaries were feed production through transporting finished cattle off-farm.

Project personnel then combined the results of all three locations to prioritize the top scenarios, which were turned into a series of graphics and narratives. The participants were then brought together for a second focus group to brainstorm management and technology options that producers were already implementing or might consider implementing. These were then sorted based on their effectiveness across multiple climate scenarios, or robustness. The options where also sorted by the readiness of the known information: Extension materials already available, research data available but few Extension materials, and research needed.

Graphic depicting warm/dry, warm/wet, cold/dry, cold/wet conditions on the farm during winter-spring

Graphic depicting hot/dry, hot/wet, cool/dry, cool/wet conditions on the farm during summer-fall

What have we learned?

The key climate drivers were consistent across all focus groups: temperature and precipitation, ranging from below average to above average. In order to best capture the impacts, the participants separated winter/spring and summer/fall.

This method of using focus groups as our initial interaction with producers on climate change was well received. Most all farmers love to talk about the weather, so discussing historical trends and their experiences with it as well as being upfront with the uncertainties in future projections, while emphasizing the need for proactive planning seemed to resonate.

With so many competing interests for producers’ time, as well as a new programming area, it was critical to have trusted local educators to invite participants. Getting participants to the second round of focus groups was also more difficult, so future efforts should considering hosting a single, full day focus group, or allowing the participants to set the date for the second focus group, providing more motivation to attend.

Future Plans

The scenarios and related management options will be used to develop and enhance Extension programming and resources as well as inform new research efforts. The goal is to provide a suite of robust management options and tools to help producers make better decisions for their operation.

Corresponding author, title, and affiliation

Crystal Powers, Extension Engineer, University of Nebraska – Lincoln

Corresponding author email

cpowers2@unl.edu

Other authors

Rick Stowell, Associate Professor at University of Nebraska – Lincoln

Additional information

Crystal Powers

402-472-0888

155 Chase Hall, East Campus

Lincoln, NE 68583

Acknowledgements

Thank you to the project team:

University of Nebraska – Lincoln: Troy Walz, Daren Redfearn, Tyler Williams, Al Dutcher, Larry Howard, Steve Hu, Matthew Luebbe, Galen Erickson, Tonya Haigh

South Dakota State University: Erin Cortus, Joseph Darrington,

This project was supported by the USDA Northern Plains Regional Climate Hub and Agricultural and Food Research Initiative Competitive Grant No. 2011-67003-30206 from the USDA National Institute of Food and Agriculture.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

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Livestock Methane Emissions Estimated and Mapped at a County-level Scale for the Contiguous United States


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Purpose         

This analysis of methane emissions used a “bottom-up” approach based on animal inventories, feed dry matter intake, and emission factors to estimate county-level enteric (cattle) and manure (cattle, swine, and poultry) methane emissions for the contiguous United States.

What did we do? 

Methane emissions from enteric and manure sources were estimated on a county-level and placed on a map for the lower 48 states of the US. Enteric emissions were estimated as the product of animal population, feed dry matter intake (DMI), and emissions per unit of DMI. Manure emission estimates were calculated using published US EPA protocols and factors. National Agricultural Statistic Services (NASS) data was utilized to provide animal populations. Cattle values were estimated for every county in the 48 contiguous states of the United States. Swine and poultry estimates were conducted on a county basis for states with the highest populations of each species and on a state-level for less populated states. Estimates were placed on county-level maps to help visual identification of methane emission ‘hot spots’. Estimates from this project were compared with those published by the EPA, and to the European Environmental Agency’s Emission Database for Global Atmospheric Research (EDGAR).

What have we learned? 

Overall, the bottom-up approach used in this analysis yielded total livestock methane emissions (8,888 Gg/yr) that are comparable to current USEPA estimates (9,117 Gg/yr) and to estimates from the global gridded
EDGAR inventory (8,657 Gg/yr), used previously in a number of top-down studies. However, the
spatial distribution of emissions developed in this analysis differed significantly from that of
EDGAR.

Methane emissions from manure sources vary widely and research on this subject is needed. US EPA maximum methane generation potential estimation values are based on research published from 1976 to 1984, and may not accurately reflect modern rations and management standards. While some current research provides methane emission data, a literature review was unable to provide emission generation estimators that could replace EPA values across species, animal categories within species, and variations in manure handling practices.

Future Plans    

This work provides tabular data as well as a visual distribution map of methane emission estimates from enteric (cattle) and manure (cattle, swine, poultry) sources. Future improvement of products from this project is possible with improved manure methane emission data and refinements of factors used within the calculations of the project.

Corresponding author, title, and affiliation        

Robert Meinen, Senior Extension Associate, Penn State University Department of Animal Science

Corresponding author email    

rjm134@psu.edu

Other authors   

Alexander Hristov (Principal Investigator), Professor of Dairy Nutrition, Penn State University Department of Animal Science Michael Harper, Graduate Assistant, Penn State University Department of Animal Science Richard Day, Associate Professor of Soil

Additional information                

None.

Acknowledgements       

Funding for this project was provided by ExxonMobil Research and Engineering.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

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Evaluation of a Model to Predict Enteric Methane Production from Feedlot Cattle


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Purpose

Continual refinement of methods estimating enteric methane production in beef finishing cattle provides a more accurate assessment of the environmental impact of the beef industry.  The USDA-OCE publication “Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory” identified conservation practices and management strategies for reducing greenhouse gas emissions while improving agriculture production (Eve et al., 2014).  In Chapter 5 a new method to estimate effects of nutrition and management on enteric methane production of feedlot cattle is provided.  The system recommends using adjustment factors to correct the IPCC (2006) tier 2 Methane Conversion Factor (Ym) of 3.0% of gross energy intake to an adjusted Ym.  Adjustment factors are used for dietary grain and fat concentrations, grain type and processing method, and ionophore use.  These adjustment factors let beef producers more accurately determine the enteric methane production associated with their individual finishing operation.

What Did We Do?

To evaluate this new model, we developed a database consisting of 36 refereed publications, with 75 treatment means.  The focus of this database was to identify published research relating to high concentration beef finishing that provided methane as a percent of gross energy, or provided enough information for calculation.  Treatments containing greater than 20% forage were excluded, as they are not representative of a high concentration finishing diet.  Additionally, treatment diets utilizing a methane mitigation agent were excluded from the database. 

What Have We Learned?

This database encompassed 75 treatment means containing a wide range in weight, intake and protein of the diets.  Body weight, dry matter intake, and dietary crude protein concentrations for the database ranged from 150 to 723 kg, 4.78 to 12.9 kg, and 9.4 to 23%, respectively.  Predicted Ym had a significant but relatively low correlation (r = 0.31, P = 0.0077) to actual Ym.  However, when one experiment (4 treatments) with very high methane values (likely a result of manure CH4) was removed, the correlation improved (r = 0.62, P < 0.0001), resulting in the following relationship:  Predicted Ym = 2.23 + (0.41 * actual YM) (r2 = 0.39, RMSE = 0.58).  Predicted g of CH4 produced daily were highly correlated to actual g of CH4/d (r2 = 0.63, RMSE = 22.61), and predicted CH4 produced, as a percentage of digestible energy intake, was highly correlated to actual CH4 per kcal of digestible energy intake, DEI (r2 = 0.46, RMSE = 0.61).  Under the conditions of this investigation, the new model moderately predicted enteric methane production from feedlot cattle fed high-concentrate diets.

Future Plans

The database will be expanded as refereed publications suitable to the selection criteria are identified.  Trials with greater forage inclusion will be evaluated to test the robustness of the model and evaluate the correlation to IPPC (2006) estimations. 

Corresponding author (name, title, affiliation) 

Tracy D. Jennings, Associate Research Scientist, Texas A&M AgriLife Research

Corresponding author email address  

Tracy.Jennings@ag.tamu.edu

Other Authors 

Kristen Johnson, Professor, Washington State University; Luis Tedeschi, Professor, Texas A&M University; Michael Galyean, Provost, Texas Tech University, Richard Todd, Soil Scientist, USDA-ARS; N. Andy Cole, Retired Animal Scientist, USDA-ARS

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

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Methods for Regulating Dry Matter Intake in Grazing Horses


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Purpose 

Pasture dry matter intake of many horses (e.g., mature idle horses) exceeds that necessary to provide daily energy requirements creating an inefficiency. One strategy for regulating pasture intake is to restrict the herbage mass (HM) available for grazing by “pre-grazing” with horses having higher nutrient requirements (e.g., work, growth, lactation), or an entirely different species (e.g., cattle, sheep or goats) using a “leader-follower” rotational grazing system. Another strategy for regulating pasture intake is to restrict the time allowed for grazing. Both methods have the potential to improve the efficiency of pasture use by preventing over-consumption.

What did we do? 

Two experiments were conducted to evaluate the effectiveness of regulating pasture intake by: 1) restricting HM available for grazing, or 2) restricting time allowed for grazing. In the first experiment six mature geldings were assigned to a HIGH (n=3) or LOW (n=3) density HM pasture (0.37 ha) for a 7 d. Treatments were reversed and carried out for an additional 7 d. The LOW pasture HM was achieved by mowing to a predetermined sward height that yielded a target HM. Mowing was used to achieve the target HM, instead of “leader-follower” rotational grazing, in order to accurately obtain the desired target HM. Herbage mass of each grazing cell was estimated using a weighted falling plate meter according to Vibart et al. (1). Body weight (BW) was measured on d-0 and 7 and changes in BW were used to reflect differences in DM intake between treatments. Mean HM available at the start of grazing was 876 and 2180 ± 76 kg DM/ha, for LOW and HIGH, respectively (Treatment P < .001), and corresponds to approximately 11 and 27 kg DM•d^-1•hd^-1 available for grazing, for LOW and HIGH, respectively, assuming a grazing efficiency of 70%. Herbage mass density decreased from d-1 to 7 (Treatment x Day; P < 0.001) by 148 and 771 ± 105 kg DM/ha for LOW and HIGH, respectively. The magnitude of BW change tended (P = .06) to be greater for LOW (-11.5 ± 3.9 kg) than HIGH (3.3 ± 3.9). The tendency for BW loss in LOW was likely a function of decreased intake leading to decreased gut fill, as opposed to a body tissue loss, given the estimated initial HM for LOW was more than adequate to meet energy requirements of all 3 horses over the 7-d period (i.e., approximately 11 kg DM•d^-1•hd^-1) (3). The greater HM reduction in HIGH, as compared to LOW, suggests horses in HIGH consumed more forage than required to meet maintenance energy requirements (e.g., potentially 14 kg DM/d), and! represen ts inefficient use of pasture.

A second experiment using eight mature geldings maintained in a single pasture (1.5 ha) and containing approximately 3,000 kg DM/ha was conducted to determine the effect of restricting time available for grazing on pasture DM intake. Horses were randomly assigned to either continuous grazing (CG; n=4) or restricted grazing (RG; n=4) for 14 d. Horses in the RG group were muzzled to prevent grazing from 1600 to 800 the following day, but otherwise allowed to graze freely. Body weight was measured on d-0, 7 and 14. Differences in body weight between treatments were used as an indicator of differences in pasture DM intake. Body weight was not different between treatments on d-0, however BW increased from d-0 to 7 for CG (22 ± 6.6 kg; P < .01), and decreased over the same period for RG (-19 ± 6.6 kg; P < .01). The gain in BW along with the initial 3,000 kg DM/ha available for grazing (approximately 28 kg DM•d-1•hd-1) suggests CG consumed DM well above that required for meeting maintenance energy requirements; whereas the loss of BW in RG suggests reduced DM intake as compared to CG. A longer term study is necessary to determine if BW change observed for RG stabilizes or continues on a downward trajectory, indicating restriction was too severe.

1. Vibart RE, White-Bennet SL, Green JT, Washburn SP. Visual assessment versus compressed sward heights as predictors of forage biomass in cool-season pastures. J Dairy Sci. 2004;87:36.

2. Walker GA. Common Statistical Methods for Clinical Research. Vol. 2nd. Cary, NC: SAS Institute, Inc; 2002.

3. NRC. Nutrient Requirements of Horses: Sixth Revised Edition. Washington, D.C.: The National Academies Press; 2007. 360 p.

What have we learned?        

The results of both experiments suggest that: 1) Mature idle horses, continuously grazing abundant pasture, consume more DM than is necessary to meet daily energy requirements representing inefficiency, 2) restriction of either herbage mass available for grazing, or time available for grazing can be developed as tools to regulate pasture DM intake of grazing horses, and ultimately enhance efficiency of pasture use.

Future Plans    

Future plans include designing experiments to refine both restriction of herbage mass available for grazing, and time available for grazing as practical methods for improving the efficiency of feeding horses on pasture.

Corresponding author, title, and affiliation        

Paul D. Siciliano, Professor, North Carolina State University

Corresponding author email  

Paul_Siciliano@ncsu.edu

Other authors   

Morghan A. Bowman, Graduate Research Assistant, North Carolina State University

Additional information              

Glunk, E.C., Pratt-Phillips, SE and Siciliano, P.D. 2013. Effect of restricted pasture access on pasture dry matter intake rate, dietary energy intake and fecal pH in horses. J. of Equine Vet. Sci. 33(6):421-426.

Dowler, L.E., Siciliano, P.D., Pratt-Phillips, S.E., and Poore, M. 2012. Determination of pasture dry matter intake rates in different seasons and their application in grazing management. J. Equine Vet. Sci. 32(2):85-92.

Siciliano, P.D. and S. Schmitt. 2012. Effect of restricted grazing on hindgut pH and fluid balance. J. Equine Vet. Sci. 32(9):558-561.

Acknowledgements       

This project was supported by the North Carolina Agricultural Research Service.

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

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Nutrient Cycling in Horse Pastures


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Purpose 

This presentation will review the existing multi-species literature on nutrient cycling and how it is affected by the horse’s diet and rotational grazing.

Grazed pastures, particularly rotationally grazed pastures, recycle nutrients faster than ungrazed pastures. Nutrients on pasture land enter through animal waste, and waste feed or fertilizer; they leave through removal of forage, leaching/runoff, or animal product/waste removal. Taking away the animal component removes about half of the inputs needed to recycle the nutrients. Dietary nitrogen (N), phosphorus (P) and potassium (K) are required for basic maintenance of horses; however, not all of what is consumed is used by the animal, therefore the dietary concentrations of these nutrients will impact the nutrient cycling. Digestibility of N, P and K in horses is approximately 80, 25 and 75 %, respectively. What does not get digested will end up excreted back into the soil.

What did we do? 

For example, in one study eight Standardbred mares were divided into two groups and received diets of grass hay and grain. The high P (HP) group received 142 g/d of NaH2PO4, formulated to provide 4.5-times the dietary P requirement, or 65 g phosphorus/d. The low P (LP) group received 28 g of phosphorus/d in the basal diet. Data showed that horses receiving the HP diet excreted higher P and water extractable P in the manure than those fed the LP diet (Table 1; Westendorf and Williams, 2015). The same goes for N, where one study used a treatment group that was supplemented with 700 g/d of soybean meal top dressed on 500 g of sweet feed per day (TRT; 1042 g protein/d DM total), while the control group received the sweet feed meals without the soybean meal (CON; 703 g protein/d total). Both groups were also fed 8 kg/d of a grass hay mix (562 g protein /d DM), water and salt ad libitum. Horses fed the TRT diet excreted more N and NH3 than horses fed the CON diet (Figure 1; Williams et al., 2011).

Nutrient Cycling in horse pastures: Tables and Figures

What have we learned? 

More intensive grazing also creates an increased rate of nutrient cycling due to the added animal inputs on the land. Even though no horse related studies have been performed on this topic studies in cattle have found that plant-available N levels doubled when cattle were rotationally grazed with five grazings per season instead of three (Baron et al., 2002). Kenny (2016) looked at horses grazed under either a continuous or rotational grazing system (see Pictures 1 and 2, Left to Right, respectively) and found no differences in system after one year of grazing, however, the author concludes that more time on the system could have generated differences.

Other factors that affect the rate of nutrient cycling include amount of legumes in the pasture, distribution of manure on pastures (i.e. relation to water, shelters and fencing), and use or rates of fertilizer.

 

Horse in pastureRotational grazing horse

Future Plans    

More equine specific studies need to be performed looking at how grazing systems and equine diets affect nutrient cycling and how horse farm owners can utilize this to best manage their farm for optimal nutrient utilization.

Corresponding author, title, and affiliation        

Carey A. Williams, Equine Extension Specialist, Rutgers, the State University of New Jersey, Department of Animal Science

Corresponding author email    

carey.williams@rutgers.edu

Additional information 

References:

Baron, V. S., E. Mapfumo, A. C. Dick, M. A. Naeth, E. K. Okine, and D. S. Chanasyk. 2002. Grazing intensity impacts on pasture carbon and nitrogen flow. J. Range Manage. 55:525-541.

Kenny, L. B. 2016. The Effects of Rotational and Continuous Grazing on Horses, Pasture Condition, and Soil Properties. Master thesis, Rutgers, the State University of New Jersey, New Brunswick, NJ.

Westendorf, M. L., and C. A. Williams. 2015. Effects of excess dietary phosphorus on fecal phosphorus excretion and water extractable phosphorus in horses. J. Equine Vet. Sci. 35:495-498. doi:10.1016/j.jevs.2015.01.020

Williams, C. A., C. Urban, and M. L. Westendorf. 2011. Dietary protein affects nitrogen and ammonia excretion in horses. J. Equine Vet. Sci. 31:305-306.

 

The authors are solely responsible for the content of these proceedings. The technical information does not necessarily reflect the official position of the sponsoring agencies or institutions represented by planning committee members, and inclusion and distribution herein does not constitute an endorsement of views expressed by the same. Printed materials included herein are not refereed publications. Citations should appear as follows. EXAMPLE: Authors. 2017. Title of presentation. Waste to Worth: Spreading Science and Solutions. Cary, NC. April 18-21, 2017. URL of this page. Accessed on: today’s date.

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