1. Particulate matter adjacent
to cattle deep-bedded
monoslope facilities
Mindy J. Spiehs
April 4, 2013
Waste to Worth
Denver, CO

2. Project Overview
• Project is part of USDA AFRI Air Quality Grant
– South Dakota State University
– Iowa State University
– Livestock Poultry and Environmental Learning
Center
– USDA ARS
• Meat Animal Research Center, Clay Center, NE
• Cotton Production and Processing Research Unit,
Lubbock, TX

5. Bedding and manure management
• Producers manage
bedding/manure two
ways:
– Allow a bedded pack to
accumulate in center or
pen
– Scrape and haul all bedding
and manure weekly
• Manure may be stored
under roof in manure bay
or in outdoor pile until
land applied
• Fresh bedding added to
pack 1 – 2 times per week

6. Purpose of Air Quality Grant
• Gather baseline emission data from beef
confinement barns
• Evaluate 2 manure handling systems
Weekly Scrape and Haul
South Dakota Sites
Bedpack
Iowa Sites

7. Monitoring Weather
• On-site weather
station measured
– Wind direction
– Wind speed
– Ambient air
temperature
– Relative humidity

8. Monitoring the Barns
• Two barns in South Dakota and
two barns in Iowa were
monitored
– Two mobile instrument trailers
were rotated between the barns
– Continuous gas measurements
were taken from each barn for one
month each season for two years
• Two air inlets on the south side
of the barn and six air inlets on
the north side of the barn
continuously collected air
samples to analyze for
– Ammonia
– Hydrogen sulfide
– Methane
– Carbon dioxide
– Nitrous oxide
• Particulate matter was
monitored periodically

9. Monitoring Particulate Matter
• South Dakota Sites
– Measured using Minivols
– Collected baseline
emission data
• Iowa Site
– Measured using Lo-Vol
Particulate Air Samplers
– Collected baseline
emission data
– Evaluated particulate
matter concentration
relative to management
events

10. Objective
• Compare particulate matter concentration
adjacent to a deep-bedded monoslope facility
during normal operation and a bedding event.

11. Sampling procedure
• Lo-Vol Particulate
Samplers
– Three placed 4.6 m (15 ft)
from the north side of the
building
– Three placed 4.6 m (15 ft)
from the south side of the
building
– 36.6 m (120 ft) between
the samplers on each side
• Average sampler flow
rate was 16.7 L/min.

13. Sampling procedure
• Each sampler contained pre-weighed filters
• At the end of the sampling period, filters were collected
and sent to USDA ARS Cotton Production and Processing
Research Unit, Lubbock, TX to determine total
suspended particles (TSP).
• Samples were collected over two five-day periods
– April 28 – May 5, 2011
– June 24 – July 1, 2011
• Each sample period included three 24-hr collections
during normal operation and two 3-hr collections during
a bedding event

14. Statistical Analysis
• Data were analyzed using SAS PROC MIXED to
determine differences between sampling events
(Bedding vs. Normal Operation) and sampling
periods (April – May vs. June – July)
• No event by sampling period interaction was
detected (P = 0.1794)
• No significant difference between sampling
periods was detected (P = 0.1807)

15. Results

16. Bedding Event
Prevailing
South wind
Bedding Event
Prevailing
North wind

17. Bedding Event
Slight south wind
Bedding Event
Wind changed
direction during
sampling

18. Average Concentrations
• Average 24-hr TSP concentration on days of
normal operation was 58.6 ± 3.9 µg/m3
• Average 3-hr particulate matter concentration
during a bedding event was 702.2 ± 266.1
µg/m3
• TSP significantly higher during bedding events
compared to normal operations (P = 0.0040)

19. Conclusions
• 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 but quickly return to baseline levels
following bedding event.

20. Thank You!