Evaluation of the Influences of New Sustainable Bedding Materials with Stacked Litter Management on Factors that Benefit Turkey Health and Environment

Progress report for ONE21-387

Project Type: Partnership
Funds awarded in 2021: $27,825.00
Projected End Date: 06/30/2023
Grant Recipient: PittMoss LLC
Region: Northeast
State: Pennsylvania
Project Leader:
Mary Deemer
PittMoss LLC
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Project Information

Project Objectives:

This project seeks to advance poultry production using a sustainable and more environmentally compatible bedding material. We will compare the newly manufactured lignocellulosic materials verse sawdust bedding and with the properties that promote bird health and wellbeing.

The project will:

  1. Compare the new bedding materials to sawdust for effectiveness when used in a stacked bedding system to:
    1. Absorb and hold ammonium,
    2. Avoid conversion of ammonium to gaseous ammonia,
    3. Absorb moisture from excreta,
    4. Improve moisture release properties,
    5. Maintain lower surface moisture,
    6. Hold nitrogenous compounds in manure storage.
  2. Observe bird acceptance by observing time and behavior on the compared bedding materials and comparing the accumulation of manure and caking.

The information collected in the trial of the new bedding materials and the use method of “Undisturbed Layered Stacked Litter” could encourage a new management style that is a more sustainable, environmentally conscious, and energy efficient method for litter management. The project would serve as a demonstration of the benefits the manufactured bedding provides which lead to increased bird health and profitability. The developed information will have application to the smallest back-yard grower to large commercial operations. It will stimulate further innovations for more environmentally sustainable production.


Bird health, growth, wellbeing , and profitability are dependent on good litter management systems. Small and large farmers are facing social pressures for odor control, governmental regulations, and environmental concerns. In the Chesapeake Bay nutrient pollution of ground water is highly attributed to the poultry industry   (Rogers, 2017).   Efforts are needed to more aggressively develop materials, methods, and management systems to more sustainably produce poultry with increased environmental stewardship.

Growers, poultry enthusiasts, and researchers have said that “As the litter goes, so goes the flock!” (Barkley 2017). The quality and effectiveness of bedding impacts; mortality, feed conversion, growth rate, disease pressure, foot pad health and breast quality, and overall bird health. Farmers are most concerned with controlling ammonia emissions, surface moisture, and labor required in managing the bedding.

Ammonia emissions must be maintained below 25 ppm for bird health, which is about the level detectable by the human nose. Control with alternative bedding during the early weeks of production has commonly been effective (Barkley, 2017). However, as bedding cakes over with feces emission levels increase, and control of ammonia and moisture become much more difficult. Many growers apply additional chemical additives to help reduce the emissions.

Litter surface moisture reduction is a primary goal to limit disease, improve bird health, and reduce foot pad dermatitis (Shepard 2017). Good ventilation is essential. Considerable heating is required for production, however, ventilation fans exhaust the moisture and ammonia, wasting energy and polluting the atmosphere.

This project proposes a solution to reduce in house environmental gaseous ammonia pollution and decrease litter moisture to create an environment to improve bird health and growth.

An invention by PittMoss LLC for producing sustainable potting soils from recycled waste cellulosic materials applies here. The processed cellulosic material is composed of exposed activated fibers with a remarkably high ability to absorb moisture and ammonium. Seeing that, some PittMoss LLC employees felt that it was logical that the material would also have value in absorbing ammonium as an animal bedding. The material has a physical structure that increases internal porosity and provides better fluid absorption and translocations. An employee with a backyard chicken house tried the material and thought it was fantastic. The formulation was then tried in an organic commercial broiler operation where it significantly reduced gaseous ammonia levels and reduced mortality, gave cleaner foot pads, increased feed conversion, and produced larger birds. Then a larger commercial farm compared the new material to wood shavings and the results were excellent. While these trials were very promising the current cost is too high for using it at about 3 to 4 inches. Since it appears that the absorptivity and drying properties are quickly blocked by the caking over with feces it was assessed that a change to repeated thin applications in an “Undisturbed Layered Stacked Litter” management system may be very effective in reducing ammonia and drying the litter. Therefore, this system must be tried and demonstrated in a carefully monitored system to improve bird health and environmental quality more sustainably.


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  • Charles Bethke - Technical Advisor (Researcher)
  • Dave Jones - Producer


Materials and methods:
manufacturing process
PittMoss production employee making the ag fiber-based bedding. (3.21.22)

Key to this trial is a comparison of the effectiveness with property changes of four bedding materials when used in an “Undisturbed Layered Stacked Litter” management system. The focus is on quantifying and monitoring properties that are known to influence health, growth, and impacts on the environment.

Four bedding formulations will be trialed. Sawdust is the control and has typically been used by the farmer. Three other new and unique cellulosic materials will be trialed. All are substrates engineered and manufactured by PittMoss. They are composed of recycled cardboard, newspaper, and natural farm raised fibers. Some of the them contain approved organic natural mineral additives that can influence in the abilities to absorb and retain ammonium, absorb liquids, and influence moisture management. All are designed to provide a high degree of exposure to fiber surfaces while having high internal porosity for absorption while allowing increased gas exchange. The high rate of hydraulic conductivity provides easy surface drying and moisture movement. These formulations are proprietary and will be identified as “A”, “B”, and “C”. Bedding “A” is a basic lignocellulosic blend and has already been proven effective and advantageous in broiler production. Bedding “B” is like “A” but modified with minerals to remain more acidic and further avoid release of gaseous ammonia. Bedding “C” is further structurally modified using locally raised biomass to further increase the physical structure and resilience against compaction. While these properties are present at installation the changes under the rigors of growth are expected to alter the properties and effectiveness. Monitoring these changes over the growing period in “Undisturbed Layered Stacked Litter” management systems is expected to show exceptional values for poultry production.

Initial bedding install
Four types of Bedding Laid out in Pen 1 (4.2.22)

For comparisons in production the trialing pen (25’x25’) will be partitioned into 4 sections across the watering and feeding systems so that uniformity exist in all the sectors. All heating, feeding, and watering will be uniform and efforts to maintain uniform ventilation will be made. Circulating fans will be used to equalize temperature and air movement. To begin a 3” layer of each bedding will be put down on each quadrant of the clean floor. After two days 1000 turkey poults will be introduced into the pen with the four communal sectors.

Birds will be carefully observed by Mr. Jones during the first two weeks and the differences in apparent comfort and dwell time on the different substrates will be noted. After 2 weeks the first of a series of observations, measurements and litter sample collections (designated as “LSC”) will commence. The on-site data will include ambient ammonia levels (with 10 replicates at 12 inches above each bedding type), bird observations including dwell time and apparent comfort on each litter type, and litter caking will be rated. Sampling for off-site analyses will include sample collection (from full depth of the bedding) with 3 representative samples from each of the 4 bedding types which are then each combined into one composite sample per bedding type for lab testing. All from representative areas (avoiding waterers, feeders, and edges), which will make 4 composite samples for each LSC. Ammonia measurements will be taken with a Forensic Detectors portable ammonia meter. The surface caking on the litter will be scored as to the

First poults arrive.
First round of 1200 poults arrive. (4.22.22)

degree of caking according to the system described by Amy Barkley (2017). A repeated LSC will be taken two weeks later just before the first batch of poults are moved. After the sampling and removal of the poults the area will be prepared for the second batch. Any holes and mounds will be roughly leveled and a new layer of only 1” of fresh bedding of each formulation (sawdust, A, B, & C), will be applied on top of the respective existing litter types. After at least one days a second batch of poults will be populated into the emptied and redressed pen. Then at two weeks and four weeks another series of LSC will take place. This cycle will also happen for the third, fourth and fifth batch of poults. Additionally, the last set of poults will remain in the original brooder pen to grow out and finish the season. During the grow-out a series of three monthly top-up applications of 1” of the respective litter types will be spread onto the respective trial sections to finish the grow out. In the grow out monthly LSC will be taken. From this sequential sampling the physical and chemical testing will be used to profile effect on bird health and environmental impact.


Ambient Ammonium Levels: (spot measurement with Forensic Detectors portable gas meter.) performed on sight.

pH: North Carolina State University Substrates Lab Std. Method (NCSU-SUB-METH) performed at PittMoss Q/C Lab on each sample.

Nitrogen Balance (Total N, Ammoniacal N, Urea, Nitrate, and Nitrite): (performed by MMI Lab using USDA Methods), four sample composites of the virgin bedding materials, bedding after first two weeks, and again at the end of the season will be performed.

Total Nutrient Analysis: (performed by MMI Labs USDA Methods) four sample composites of the virgin bedding materials, bedding after first two weeks, and again at the end of the season will be performed.

Total Soluble Salts (Electrical conductivity): (NCSU-SUB-METH) performed at PittMoss Q/C Lab on each sample.

Wet (as is) and Dry Bulk Density: (NCSU-SUB-METH) performed at PittMoss Q/C Lab using on each sample.

Moisture (as is) on Dry Weight and Volume Basis: (NCSU-SUB-METH) performed at PittMoss Q/C Lab on each sample.

Moisture Holding Capacity on Weight and Volume Basis: (NCSU-SUB-METH) performed at PittMoss Q/C Lab on each sample.

Hydraulic Conductivity: (NCSU-SUB-METH) performed by NCSU Substrates Lab three sample composites performed at the end of each flock of poults and monthly in final grow out.

Space Distribution for Air, Water, and Solids: (NCSU-SUB-METH) performed at PittMoss Q/C Lab using on each sample.

Moisture Release Curves: (NCSU-SUB-POROMETER METH) performed by NCSU Substrates Lab four sample composites performed at the end of each flock of poults and monthly in final grow out.

Water Activity Levels: (Method used by Amy Barkley) using four sample composites performed at the end of each flock of poults and monthly in final grow out.

Relative Drying Rate: Three replicates of the virgin bedding samples and control, using self-designed table top in tray methods based on a method by Amy Barkley).

Composite samples
Composite samples of bedding packed to ship to the labs.

Data from each parameter measured and displayed chronologically to demonstrate the influence of the litter stacking over time. The parameters will be correlated to the gaseous ammonia, nitrogen levels, bird acceptance, litter caking and among the other measured properties. Statistical analyses including mean separation (Tukey’s) will be applied to define significant differences in the treatments over time and reported where appropriate. Through multiple linear regression analysis, relationships will be developed to demonstrate shifts in properties over time.   Graphics representations of key findings will be developed to display the factors that had the highest correlations to measured parameters of the litter. Finally, the differences in the four bedding materials will be rated and displayed in charts and tables for presentation. Findings will be reported in a series of interim reports, culminating in a final report.


Research results and discussion:

January 2022 Report:

We have measured the moisture absorbing properties of the bedding materials to be used and find that the Ag fiber, paper, and cardboard based materials have very high moisture holding compared to saw dust.  Also, the dry and moist bulk densities vary considerably and a baseline for these properties is being established.  A late March beginning of the pen trials is planned.

January 2023 report:

The bedding material trials with this crop of turkeys has been completed. There were six cohorts of poults totaling over 5,500 turkeys spread over the months of April to July. Densities were often times very high depending on the schedule of incoming poults, rapidly growing adolescents and final processed birds. Bedding was applied at the farmer's discretion and in four major events between poult cohorts while pen 1 was empty. The depth of bedding grew from 3" in early April to 30-36" in total depth by October. The farmer ran out of trial bedding in late July, perhaps due to over application, and finished the season with topdressings of sawdust as needed. Adjacent pens (2 &3) were added to data collection events to provide a comprehensive look at the farmer's usual operations of layering with sawdust.   Data and samples were collected from six sampling events of the project area and over ten visits to the farm.  All sampling events have associated lab work that is still being analyzed.  Many laboratory tests have been completed.  Four of the fourteen categories of measurements remain to be finished. An update of some of the findings is presented here.

 Ambient Ammonium Levels:

The ammonium levels in the air were measured at about one foot above the surface of the treatment area. Often because the fans were operating and the vents were open the levels were very low or were not detectable.  A representative of the measurements on May 18th is presented here.

Representative Ammonia Measurements

Note that the sawdust had higher ammonium levels than the alternate bedding materials.

 Influences On pH:

Wide variations are observed in the impact of the bedding materials on the pH. This is significant since acidic pH levels reduce the ammonia gas emissions. There were significant differences in the pH between the alternate beddings and the sawdust and also over time. These changes in pH will be discussed in the final report, but as a short snapshot of changes in pH see the data from the compost analysis of the litter.

Final pH of Litter from Compost Analysis

In that graphic we see that the sawdust, which was used in the experiment and also in Pen-2  and Pen-3, resulted in a much higher pH at the end of production.

Total Soluble Salts:

 Some variation among the bedding materials was observed in how they accumulated soluble salts. This is important when considering the total loading of soluble salts that the bedding can absorb and in avoiding runoff.

Final Soluble Salts from Compost Analysis

Additionally, the soluble salts present an indication of levels of soluble nutrients that will be easily leached from the litter (manure) when stored or applied to the field.  Further discussions of these influences will be in the final report.

Nitrogen Balance:

A primary part of this research was to determine the impact of the bedding on the forms of nitrogen that would remain in the litter. This was an especially important reason for determining the soluble forms of nitrogen. The levels of total nitrogen are presented here:

Soluble N levels from SME

The forms of nitrogen (nitrate, urea, and ammonium) will be broken down in detail in the final report. Additionally, the soluble versus the total nitrogen content of the various bedding materials will be discussed in detail.  At this time, it is clear that some of the alternate bedding materials have a tendency to sequester the nitrogen more effectively, thus reducing the probability of leaching and runoff from field applied manures.  The current data indicates that better nitrogen stabilization and reduced gaseous escape of ammonium takes place in some of the alternate bedding materials.

Total Nutrient Analysis:

Total nutrient analyses were made at the beginning and end of cropping. Both soluble nutrient measurements using the saturated media extract method and the total digested nutrient content (compost analyses) in the bedding material were analyzed.  Differences in solubility and level of nutrients are distinguished by the analyses. Of particular significance is the phosphate and nitrogen variability in the bedding materials. Another interesting observation is the tendency of the bedding materials to sequester many nutrients especially potassium, which is considered a very soluble ion in most substrates. The graphics below present effects associated with potassium and phosphorus solubility.

Soluble Potassium from SME 

Soluble Phosphorus Increase SME

These differences will be described in detail in the final report.

Comparisons of Wet and Dry Bulk Densities:

The variations in wet and dry bulk densities give us information on how the various litter materials absorb and hold moisture.  There are meaningful differences between the adding of materials. Sawdust seems to be relatively inefficient in holding moisture, and is considerably heavier. Further, the dry bulk density provides a reference point for the relative levels of moisture that can be held.  The graphic below shows differences in the wet and dry bulk density after cropping. 

Average Bulk Densities by Bedding Type

Moisture Content and Holding Ability:

The moisture content of the bedding material and its ability to absorb moisture is the most significant part of this study and will be covered in great detail in the final report.  As an update for the interim report the attached graphic present information that shows significant differences in the capability of various bedding materials to absorb solutions.  The sawdust is less efficient than the alternate substrates.

Average Moisture Content by Bedding Type

Relative Drying Rates:

Work on the relative drying rates of the various bedding materials continues. The impact of each bedding material is somewhat subjective and short-lived in production.  Newly applied bedding is easily caked over by the excreta of the birds.  However, some differences are observed between bedding types and those differences will be discussed in the final report.

Continuing Analyses:

Data is being obtained and analyzed on the "Space Distribution of Air, Water, and Solids", "Hydraulic Conductivity, "Moisture Release" and "Water Activity Levels".  These items will be discussed and presented in the final report.

Current Summary:

The work performed to date indicates that there are significant differences in the impacts of various bedding materials. Significant variations are observed in the physical and chemical properties and their influences on the behavior of the bedding. Properties such as; absorbing and managing moisture, ammonium, phosphate and other nutrients both in production and related to manure use. The health of the birds will likely be further improved by using some of these alternate bedding materials. In the final report we expect to demonstrate significant differences among bedding materials and how they impact production.







Research conclusions:

While the physical project is complete and the last turkeys went to slaughter in December, work with the collected composite samples and analysis of the associated lab results continues. PittMoss is eager to present our research conclusions in the final report and in some educational capacity. 

Participation Summary
1 Farmers participating in research

Education & Outreach Activities and Participation Summary

25 Consultations
1 Curricula, factsheets or educational tools

Participation Summary:

16 Farmers participated
9 Number of agricultural educator or service providers reached through education and outreach activities
Education/outreach description:

Pasa Conference Booth
Pasa Conference, Lancaster PA (2.10.22)
PASA Conference Booth
Educational display at Pasa Conference (2.10.22)

PittMoss had a booth at the 2022 Pasa Conference (February 9-12 2022) and created a display promoting the NE SARE partnership grant, our partner farmer and the project. The booth was manned by Mary Deemer and PittMoss staff and many quality conversations regarding our research project and sustainable bedding options for poultry with both producers and educators were had. 

The project was submitted as a presentation topic for the 2023 conference but was not selected. 






Findings from this project will be of interest to home and hobby poultry egg and meat growers, as well as commercial growers. Environmentalists will also be interested in the atmospheric emissions, waste management, and water run-off implications. Therefore, a broad audience for the results is expected. As it is impossible to schedule these events in advance of the application these items represent the effort PittMoss is ready and able to put forth into the distribution of information learned during the project. 

  1. In cooperation with industry associations and extension educators, presentations could include:
    1. Farm demonstration meetings,
    2. Videos and demonstrations will be produced,
    3. Power Point Presentations will be disseminated,
    4. A bulletin on this type of litter management would be made.
  2. A video of the project and findings will be made and presented on the poultry farm web sites.
  3. Bloggers in Poultry Management will feature the farm and project findings.
  4. Popular Industry Publications will feature articles on the new materials and processes.
  5. The Manufacturer of the Innovative material will:
    1. Disseminate findings in printed and electronic promotional advertising materials.
    2. Present the product and systems at tradeshows.
    3. Present the product and systems to farmers, integrators, and suppliers.
    4. Advertise in publications.
  6. Articles on observations and information obtained will be produced for, and presented in, environmental and sustainability printed and electronic media and at association and media conferences. Some examples of outreach meetings where the presentations will be made are:
    1. PASA Conference - as a speaker or cohort of speakers depending on venue acceptance of topic
    2. Links to video presentations will be made available to Extension Agents to include in newsletters and/or build an event around
    3. HOA Conference - speaker or trade show booth 

Learning Outcomes

1 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
Key areas in which farmers reported changes in knowledge, attitude, skills and/or awareness:

Only limited preliminary observations have been made to date.  In preliminary applications and testing the farmer reported better leg health with much better foot health and fewer sores on the turkey's foot pads.

Project Outcomes

Project outcomes:

Nothing to date.

Information Products

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.