Litter Reconditioning Strategy


May 30, 2008
Gary A. Flory (1), Robert W. Peer (2), Becky Barlow (3), Doug Hughes (4), George W. Malone (5), Audrey P. McElroy (6)

May 30, 2008

Gary A. Flory (1), Robert W. Peer (2), Becky Barlow (3),

Doug Hughes (4), George W.
Malone (5), Audrey P. McElroy (6)

INTRODUCTION

Litter reconditioning has had limited use within the poultry industry as an alternative
bedding practice since the 1980’s. Litter reconditioning—also known as composting,
windrowing, pasteurization and recycling—is a process of composting litter between
flocks to extend the life of the bedding material. Interest in litter reconditioning has
grown in the last few years as the cost of quality bedding material has risen and the
availability decreased. However, this single
consideration was not sufficient to cause
widespread application of this alternative
bedding method. Today, a number of
additional factors are causing the
commercial poultry industry to take another
look at litter reconditioning. These factors
include disease challenges with reused litter,
decreased use of antibiotics in poultry
flocks, excess litter production in areas of
high poultry production, increased concerns
about pathogens in litter used as fertilizer,
and environmental concerns related to the
storage of poultry litter.

MATERIALS AND METHODS

A broiler chicken farm raising approximately 75,000 birds a year for Tyson Foods, Inc.
was identified for this study. The farm contained 2 identical 42-foot wide by 600-foot
long poultry houses. Each poultry house contained approximately 4 inches of poultry
litter evenly distributed throughout the house. In one poultry house the litter was
managed utilizing a litter reconditioning strategy. The second house served as the control
and was managed consistent with the farm’s existing litter management strategy of
removing caked litter between flocks.

Equipment, Windrow Construction and Management

On October 23, 2007, one day after the chickens were removed from the houses for
processing, a Brown Bear R24C aerator attachment on the front of a New Holland high
flow skid loader was used to aerate and mix the poultry litter in the experimental house
and construct 2 windrows. The windrows ran the length of the poultry house. Initially, 3
windrows were constructed by the aerator, but 2 of the windrows were combined to
evaluate if sufficient mass existed in a single windrow to generate adequate composting
temperatures and control pathogens. The single windrow was approximately 24 inches
tall and 5 feet wide. The combined windrow was approximately 30 inches tall and 7 feet
wide.

The windrows were turned with the aerator 4 days after construction. Six days after
construction, the windrows were spread out using a tractor mounted scraper blade to
prepare the house for the next flock of chickens. Fourteen days after the previous flock
was sent to processing, new flocks of chickens were placed in both the control and the
experimental houses.

Sampling Protocols

Both windrows in the experimental house were flagged at 10 locations approximately 60
feet apart. Temperatures within the windrows were sampled twice a day, beginning 12
hours after windrow formation as summarized in Figure 1. Temperatures were collected
using 36-inch analog compost thermometers.

Bacteriological samples were collected at the flagged locations in the windrows.
Samples were also collected in the control house at the same 60-foot intervals. Samples
were collected at each of these sampling locations 3 times throughout the composting
process. Each sample was a mixed collection of surface material and material from
approximately 6 inches deep below the litter surface on the windrows. Approximately 2
pounds of litter was collected at each sampling location and sent to a Virginia Tech
laboratory for analysis. All samples were analyzed for Salmonella, E. coli, and Total
Aerobic Plate Count.

Litter nutrient samples were collected as a composite of samples grabbed from flagged
locations in both the control and experimental houses, and collected at the beginning and
end of the composting process. Samples were analyzed for moisture, ammonium
nitrogen, total nitrogen, phosphorus as P2O5, potassium as K2O, and 8 micronutrients by
the Agricultural Service Laboratory at Clemson University.

Ambient ammonia levels in the poultry houses were analyzed throughout the composting
process in the experimental house as well as in the control house. Additionally, ammonia
levels were analyzed during the production of the first post-treatment flock. Ammonia
levels were measured with a portable ammonia meter.

A major goal of the project was to evaluate and compare the productivity of the birds
grown in the control house versus the birds produced in the experimental house
immediately following litter reconditioning. To ensure a valid comparison, Tyson Foods,
Inc. agreed to place birds from the same hatch in both the control and experimental
houses and process each house separately. Data on feed deliveries, fuel usage, ambient
temperature, processing and flock settlement were collected from each house.

PROJECT RESULTS

Windrow Temperatures

Analysis of the temperature data showed
that the smaller windrow (Windrow A)
reached and maintained optimum
composting temperatures almost as well as
the larger combined windrow (Windrow
B). The temperature goal of 135 ° F was
met and exceeded in both cases.
Additionally, Figure 1 illustrates the
temperature surge immediately following
windrow aeration at 4 days.

Bacteria Reductions

Large reductions in the bacteria levels
within the litter bedding were observed in
the experimental house when compared to
the control house. This was true of the total aerobiccount, E. coli and Salmonella.
Figure 2 illustrates the reductions in E. coli during the composting process compared to
the stable E. coli levels in the control house. Figure 3 illustrates similar results for the
Salmonella data.

Mortality

Daily mortality was logged in both
the experimental and control houses.
Analysis of this data shows mortality
within the houses staying consistent
until 17 days after flock placement.
At 17 days, the flock began to show
signs of the poultry disease Necrotic
enteritis. This farm had a long
history of enteritis which was one
reason for it’s inclusion in this study.

Necrotic enteritis is caused by the
obligate anaerobic bacteria
Clostridium perfringens which is
commonly found in soil, dust, feces
and feed and is a normal inhabitant of the intestines of healthy chickens. Historically,
Clostridium perfringens was managed through antibiotics delivered in the feed.
However, the trend in the poultry industry—driven by consumer demand—is the
reduction or elimination of antibiotics in commercial poultry. This trend has meant that
the management of enteritis, and other common poultry diseases, is more critical now
than in the past.

The difference in mortality between the experimental and control houses after the onset
of the disease is illustrated in Figure 4 with considerably lower mortality in the
experimental house.

Nutrients

Comparing the analysis of the litter in the control house and that in the experimental
house showed no significant difference in the nutrient value of the litter. Composting can
result in reduced nitrogen levels but the relative short duration of the revitalization
process did not significantly decrease the nutrient value of the litter.

Energy Usage

Heat for the poultry houses was provided by propane furnaces. Analysis of the propane
usage in the houses indicated that the experimental house used approximately 350 gallons
more propane than the control house. This was due to the increased need for ventilation
caused by higher ammonia levels in the experimental house. Increased ventilation
requires more energy to replace the heat lost exhausting the additional ammonia. The
increased ammonia was a result of mixing the litter during windrow construction and the
retention of the high moisture litter (cake) which would normally be removed during
crusting (machine removal of caked litter).

Flock Settlement

Perhaps the most dramatic result of the study
is the comparison of the two flocks of birds
when they were processed as shown in Table
1. The flock in the experimental house had a
greater average weight, better feed
conversion, greater livability, and less
condemnation. This resulted in the
production of 8,553 more pounds of poultry
meat.

Table 1 – Flock Settlement Results

	Experimental	Control
No Birds started	36,700	36.900
Lbs Feed used	272,650	268,390

No Head Sold	34,864	34,154
Gross Pounds Sold	154,280	145,640
Less Condemn Lbs	218	305
Net Pounds Sold	154,498	145,945

	Experimental	Control
Average weight	4.43	4.26
Feed conversion	1.77	1.84
Net Pound value	21.28	22.27
Liveability	95.00%	92.56%
% Condemned	0.14%	0.21%

ECONOMIC CONSIDERATIONS

The traditional litter management program
requires the complete removal of all litter
once every year or two to be replaced with 3
to 4 inches of fresh shavings. Fresh shavings
to fill a 600-foot house cost about $2,400.
Replacing litter with shavings is not required
with litter reconditioning.
Birds grown in the experimental house were
heavier, healthier, less susceptible to disease
and converted feed to muscle better. This improved performance resulted in the
production of over 8,500 pounds more chicken, which translates into a direct financial
benefit to the poultry company and an additional $1,998 for the farmer.

On the negative side of the economic equation, the experimental house used more
propane than the control house. Based on the price of propane in November of 2007, the
additional propane cost the producer approximately $700 more in the experimental house
than in the control house.

Litter reconditioning requires the use of a skid loader or a skid loader aerator attachment
such as the Brown Bear aerator used in this experiment. Traditional litter management
practices require the removal of the wet litter (cake) by a process often call crusting.

Crusting generally cost about $225 per house when completed by a custom operator.
Litter reconditioning by a custom operator would likely cost $300 per house. In addition
to the cost of the custom operator, the producer would need to level out the windrows
with a tractor and blade at the end of the composting process. Cost of time and fuel for
this operation would be approximately $100 per house.

Poultry producers who own a skid
loader could save some of the cost of
hiring a custom operator or
purchasing aeration equipment by
forming windrows with their own
equipment. However, when using a
skid loader to form windrows, there
is still a need to use crusting
equipment to remove the cake since
the skid loader does not break up the
cake as well as the aeration
equipment.

With the cost of aeration attachments such as those pictured for skid loaders ranging from
between $15,000 and $20,000, it may not be feasible for individual growers to own the
equipment. Alternative business models for implementing the litter reconditioning
strategy might include the purchase of the aeration equipment by an industry group or an
entity such as a local Soil & Water Conservation District. These organizations could then
lease the equipment to individual farmers. Another possibility is that the integrated
poultry company could purchase the equipment for use by their producers.

CONCLUSIONS

To be effective, litter reconditioning must be implemented as a long-term management
strategy. A single treatment demonstrated benefits, but multiple treatments during the
production year may be needed to break the cycle of persistent poultry diseases. Timing
of the treatments is critical to avoid increased energy cost. Our experiment demonstrated
the economic benefits of better bird health but the economic advantages of reconditioning
could have been increased by timing the treatments to minimize increased heating cost.
Litter reconditioning should be timed for use with flocks placed between late spring and
early fall to minimize these increased costs.

Litter reconditioning has the potential to ease the impact of the shortage of bedding
material. However, the real benefit of this litter management strategy is in its potential to
help manage persistent disease problems within the commercial poultry industry. Safe,
cost-effective disease management strategies are becoming more important as the use of
antibiotics in commercial poultry production decreases or is eliminated.

Finally, the environmental and health benefits of litter reconditioning appear to be
significant when litter is land applied as a soil amendment. The reduction of pathogens in
land applied litter can minimize the negative impact on grazing animals, as well as the
potential for impacts on humans and aquatic life from application field runoff.

1	Agricultural & Water Compliance Manager, Virginia Department of Environmental Quality, Valley Regional Office, P.O. Box 3000, Harrisonburg, Virginia 22801 Phone: (540) 574-7840 Email: gaflory@deq.virginia.gov
2	Agricultural Program Coordinator, Virginia Department of Environmental Quality, Valley Regional Office, P.O. Box 3000, Harrisonburg, Virginia 22801 Phone: (540) 574-7866 Email: rwpeer@deq.virginia.gov
3	Organic Resources Marketer, Shenandoah RC&D, P.O. Box 60, Verona, VA 24482 Phone: (540) 248-6080 Email: rebecca.barlow@rcdnet.net
4	Agricultural Program Specialist, Virginia Department of Environmental Quality, Valley Regional Office, P.O. Box 3000, Harrisonburg, Virginia 22801 Phone: (540) 574-7829 Email: dehughes@deq.virginia.gov
5	Extension Poultry Specialist, University of Delaware, 16684 County Seat Hwy, Georgetown, Delaware 19947 Phone: (302) 856-7303 Email: malone@udel.edu
6	Associate Professor, Virginia Tech, Blacksburg, Virginia 24061 Phone: (540) 231-8750 Email: amcelroy@vt.edu

For more information, please look at the following pages

Brown Bear Poultry Litter Report

Litter Reconditioning Stategy

In House Composting Of Litter

Greg Newhart Farm

East Coast Intergrator

Broad Creek Windrow Observations