Particulate Matter Adjacent to Cattle Deep-Bedded Monoslope Facilities

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Why Study Monoslope Barns and Air Quality?

Confined cattle facilities are an increasingly common housing system in the Northern Great Plains region.  Many of these facilities add organic bedding material to the pens once or twice per week.  Particulate matter concentrations and emissions from these facilities have not been evaluated.  The objective of this study was to quantify particulate matter concentration adjacent to a deep-bedded mono-slope facility housing cattle and to compare the concentrations during normal operation and a bedding event.

Average 24-hr total particulate matter concentration of ambient air collected from a beef deep-bedded monoslope barn.

What Did We Do?

Three Lo-Vol Particulate Samplers were placed 4.6 m from the north side of the building, and three were placed 4.6 m from the south side of the building with 36.6 m between the samplers on each side.  Average sampler flow rate was 16.7 L/min.  Samples were collected over two five-day periods (April and June 2011).  Each sample period included three 24-hr collections during normal operation and two 3-hr collections during a bedding event.  Filters were collected, conditioned for 48 hr at 21.1 °C and 35% humidity, then weighed in micrograms and analyzed on a Beckman Coulter LS 230 to determine total suspended particulate matter (TSP).

What Have We Learned?

Average 3-hr total particulate matter concentration of air collected during a bedding event of beef deep-bedded monoslope barn.

During the April sampling period, average 24-hr TSP concentration ranged from 40.1 to 91.4 µg/m3 during days of normal operation. Average 3-hr particulate matter concentration during bedding events ranged from 281.8 to 540.5 µg/m3.  During the June sampling period, 24-hr TSP concentration on days of normal operation ranged from 52.7 to 64.6 µg/m3, while 3-hr particulate matter concentration during bedding events averaged 302.4 to 1684.2 µg/m3. Sweeten et al. (1998) reported average TSP concentrations of 410 µg/m3 measures for 24 hr periods on open feedlots in Texas. In general, particulate matter concentrations adjacent to the deep-bedded monoslope facility were lower than previously reported for open lot feedlots.  Concentrations of TSP were higher during the 3-hr bedding event than during normal operation.

Future Plans

To compliment this research, data has been collected from two monoslope beef barns over the past two years as part of an AFRI-funded research grant.  MiniVol particulate samplers were used to determine PM-10 and PM-2.5 concentrations over 24-hr periods.  Data collected from this project will further define the particle size of dust being emitted from these facilities.


Mindy J. Spiehs, Research Animal Scientist, USDA – ARS Meat Animal Research Center, Clay  Center, NE,

Greg A. Holt, Research Leader, USDA- ARS Cotton Production and Processing Research Unit, Lubbock, TX

Kris D. Kohl, Extension Agricultural Engineer, Iowa State University Extension and Outreach, Storm Lake, IA

Beth E. Doran, Extension Beef Specialist, Iowa State University Extension and Outreach, Orange City, IA

David B. Parker, Professor and Director, Commerical Core Laboratory, Palo Duro Research Center, West Texas A & M University, Canyon, TX

Erin Cortus, Assistant Professor, South Dakota State University, Brookings, SD

Additional Information


The authors wish to acknowledge James (Bud) Welch and Alan Kruger for assembly and disassembly of  the particulate matter sampling equipment and Ron and Clayton Christensen for the use of their cattle facility.  Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.  USDA is an equal opportunity provider and employer.


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. 2013. Title of presentation. Waste to Worth: Spreading Science and Solutions. Denver, CO. April 1-5, 2013. URL of this page. Accessed on: today’s date.

Mono-Slope Beef Barn Air Quality Research Project

monoslope beef barnResearchers and university specialists from USDA’s Meat Animal Research Center (USMARC), South Dakota State University, and Iowa State University recently finished a four-year study looking at mono-slope beef barns and how to improve cattle and environmental performance.

How Do Mono-slope Barns Stack Up For Air Quality?

A research team worked for three years to gather baseline data for the levels of gas emissions from mono-slope beef barns. The study involved a total of four mono-slope beef barns in South Dakota and Iowa. Researchers also evaluated two different manure-handling systems to determine if there are any differences in gas emissions.

The results of that study are summarized in a eight-page publication “Air Quality in Mono-Slope Bedded Beef Barns“. They measured ammonia, hydrogen sulfide, methane, carbon dioxide, and nitrous oxide. The first three are the primary focus of the publication, since those are most commonly associated with beef feedlots. Also discussed are impacts of building orientation, manure-handling system, pen density, bedding type, and curtain opening (ventilation).

Beef Facilities Conference

Over 300 people attended the November, 2013 conference on beef confinement buildings held in Sioux Falls, South Dakota. The recordings and written papers are linked below.

Environmental and Regulatory Aspects of Beef Barns

The page numbers next to each are the location of companion written papers in the Beef Facilities Conference proceedings.

  • Results of Air Quality Research on Mono-slope Bedded Beef Barns – pages 5-9.
  • Air Quality Regulations and implications of the air quality research project – pages 10-17

The third presentation focuses on manure and nutrient production, and nutrient management for manure produced in these systems.

  • Capturing, managing, and using nutrients from the barn – pages 18-21

Producer Panel – Virtual Tours

Four producers shared aspects of their different building designs including ventilation, manure management, what works well, and things they would change. Their summaries are on pages 22-26 of the Beef Facilities Conference Proceedings.

  • Hoop buildings – one farm tour and a short synopsis of different building designs in use in Iowa
  • Mono-slope buildings – narrow and wide designs
  • Slatted floor barn (with rubber mats) – originally built without mats

Cattle Performance and Comfort In Beef Barns

University specialists compared feed intake, animal performance, carcass characteristics, and management considerations with barns compared to other systems. The page numbers next to each are the location of a companion written paper in the Beef Facilities Conference Proceedings.

The third presentation looks at international and domestic research into the use of rubber mats in deep pit barns with concrete slats.


Two live webinars were recorded and archived. The presenters included researchers, extension specialists, and farmers.

Open Houses Provide Opportunities to Learn More

Photo of a bedded beef barn in South Dakota.
It was standing room only as participants listened to station presentations in the alleyway of the mono-slope barn.

As part of the outreach plan for this project, a series of open houses were scheduled to inform cattle producers, regulatory and technical agency staff, Extension employees, service providers and legislative and local policy-makers about air quality management and manure and environmental issues with these facilities.

Over 200 people from Iowa, Minnesota, South Dakota and Nebraska attended the Mono-Slope Beef Barn Open House in June of 2011. The open house was hosted by Ron and Clayton Christensen of Royal, Iowa and featured barn and manure management, cost-sharing opportunities, the tri-state air quality project and environmental regulations.

The open house was organized by ISU Extension and Outreach, SDSU Ag and Biosystems Engineering, and the USDA Meat Animal Research Center at Clay Center, NE.  Sponsors included Animal Medical Centers of Spencer, Clay County Cattlemen’s Association, Clay County Farm Bureau, Coalition to Support Iowa’s Farmers, Farm Credit Services of America -Emmetsburg, Spencer Ag Center and Spencer Chamber of Commerce Ag Committee.

second open house was hosted in South Dakota in August of 2011. The open house was hosted by Goodwin Heritage Cattle Company, with approximately 125 people in attendance from South Dakota and neighboring states. Sponsors included Coteau Hills Cattlemen’s Association, Watertown Chamber of Commerce Ag Committee, SPN & Associates, Glacial Lakes Energy LLC., Landmark Builders Inc., South Dakota Farm Bureau, Ag United for South Dakota, Banner Associates and Form-A-Feed, Inc.

As a result of the two open houses:

  • 95% had a better understanding of the air quality regulations and why this research is needed*
  • 88% learned where they could find financial resources to construct a mono-slope barn*
  • 89% had improved knowledge about how gases and dust are measured*

*Based on 19.7% participation in a short survey after each open house

Learn more about the successes of these open houses.

A facility tour, Science Behind Environmental Policy, was held June 22, 2012 in NW Iowa.  This tour was attended by state and federal legislators, state policy makers and stakeholders representing Extension and university specialists. Enthusiasm for research efforts was proclaimed by the legislators. See what they learned.

NW Iowa cattlemen listened to Mindy Spiehs, researcher with USDA ARS Meat Animal Research Center at Clay Center, share progress about the Tri-State Air Quality Project.  The update and tour at the Christensen barn were part of a NW regional meeting sponsored by the Iowa Cattlemen’s Association on August 23, 2012.

Mindy Spiehs
Mindy Spiehs talks about the Tri-State Air Quality Project.

Waste to Worth Conference Presentations

In April, 2013 researchers presented air emissions results from this project at the Waste to Worth: Spreading Science and Solutions conference in Denver, CO. These proceedings include a short written paper, recording and links to additional information. The different aspects presented were:

The above proceedings compliment the Beef Facilities Conference recordings and webcasts on the research project (both further up on this page).


This page was developed as a part of the Monoslope Beef Barn Air Quality Research project that was funded by Agriculture and Food Research Initiative Competitive Grant no. 2010-85112-20510 awarded to South Dakota State University, USDA ARS U.S. Meat Animal Research Center, Iowa State University, and University of Nebraska – Lincoln from the USDA National Institute of Food and Agriculture. For more information about the research study, contact Erin Cortus or Mindy Spiehs For more about the outreach and extension, contact Beth Doran

project partner logos - South Dakota State University, USDA-ARS, Iowa State University, and University of Nebraska - Lincoln

Mono-Slope Beef Barns

There is growing interest in feeding cattle in bedded confinement buildings for a multitude of reasons including (but not limited to): performance advantages, limited space for open lots, and keeping manure dry as well as preventing feedlot run-off and reducing environmental concerns. Oftentimes these confined cattle are housed in mono-slope barns.

What Is a Monoslope Beef Barn?

This video is excerpted from a webcast presentation by Shawn Shouse, Iowa State University



Mono-slope barns, by definition have only one slope to their roof and are usually naturally ventilated. They are typically positioned to take advantage of seasonal climatic conditions. This means in the northern hemisphere the higher side would be south-facing with the lower side to the north. This allows for shade in the summer and sun exposure in the winter.  In bedded units, the bedding absorbs moisture and provides a softer surface for cattle to walk and lay on.

Comparing Confinement Farms with Conventional Feedlots


Shawn Shouse of Iowa State University compares
confinement systems to open lots for beef cattle.


While there are many advantages to mono-slope beef barns, the question that has been raised is: “What is the quality of air in these barns?”. A recent, on-going research project takes on this question.

Recommended Reading


Inquiries about the mono-slope barns may be directed to:

Beth Doran, Iowa State University (phone: 712-737-4230)

Kris Kohl, Iowa State University (phone: 712-732-5056)

Erin Cortus, South Dakota State University (phone: 605-688-5141)

Mindy Spiehs, U.S. Meat Animal Research Center (phone: 402-762-4271)

This page was developed as a part of the Monoslope Research project that was funded by Agriculture and Food Research Initiative Competitive Grant no. 2010-85112-20510 awarded to South Dakota State University, USDA ARS U.S. Meat Animal Research Center, Iowa State University, and University of Nebraska – Lincoln from the USDA National Institute of Food and Agriculture.

project partner logos - South Dakota State University, USDA-ARS, Iowa State University, and University of Nebraska - Lincoln

Results of Mono-Slope Beef Barn Air Quality Research – Archived Webcast

Researchers and university specialists from South Dakota State University, USDA’s Meat Animal Research Center (USMARC), and Iowa State University Extension are wrapping up a four-year study looking at concentration and emission measurements in comparison with management techniques for mono-slope beef barns and will share the results of their study. This presentation was originally broadcast on July 19, 2013. More… Continue reading “Results of Mono-Slope Beef Barn Air Quality Research – Archived Webcast”

Mono-Slope Beef Barn Design and Management

monoslope beef barnWhat is a mono-slope beef barn? It’s a newer style barn for cattle that is becoming increasingly popular in the upper Midwest.

This webinar allows you to discover what exactly is a mono-slope barn and why beef producers are building them. This presentation is part of a four-year mono-slope air quality research project and was originally broadcast on May 17, 2013. More… Continue reading “Mono-Slope Beef Barn Design and Management”