Bedding material comparison in a composting barn

Project Overview

Project Type: Farmer
Funds awarded in 2014: $11,081.00
Projected End Date: 12/31/2017
Region: Northeast
State: New York
Project Leader:
Sarah Ficken
New Moon Farms

Annual Reports


  • Animal Products: dairy


  • Animal Production: housing, animal protection and health, manure management, pasture fertility
  • Crop Production: nutrient cycling, organic fertilizers
  • Education and Training: extension, farmer to farmer, on-farm/ranch research
  • Farm Business Management: whole farm planning
  • Production Systems: holistic management
  • Soil Management: soil analysis, composting, nutrient mineralization, organic matter, soil quality/health

    Proposal summary:

    Composted bedded pack barns are an innovative solution to the problems of nutrient management, cow comfort, and manure storage faced by dairy producers in the Northeast. The largest obstacle to adoption of composted bedded pack barns is the dearth of cost-effective bedding material. Sawdust is the current best practice for bedding in composted bedded pack barns, but the cost of bedding with sawdust can exceed $0.50 per cow per day and not many cost-effective alternative bedding sources have been identified. Since composted bedded pack barns are still a relatively new housing system, there are still many gaps in the research. Peanut hulls and shredded paper are two readily available bedding sources that have characteristics suited to composting. In this study, we will divide our pack into four quadrants to compare bedding with peanuts hulls, bedding with shredded paper, bedding with a combination of peanut hulls and shredded paper, and bedding withwoodchips/sawdust. We will collect data on the pack weekly and perform statistical analyses upon the completion of the study. After our study, we will host an open farm day and create a YouTube video with a companion fact sheet to disseminate our results.

    Project objectives from proposal:

    The objective of this project is to measure the efficacy and cost-effectiveness of alternate bedding materials in a composted bedded pack barn. The sources of bedding that we will evaluate are shredded paper by product, peanut hulls, and a mixture of  both materials. Peanut hulls and shredded paper byproduct both have acceptable C:N ratios, are readily available, and have good attributes for composting. 

    Prior to beginning the experiment, we will establish a composted bedded pack that has sufficient biological activity and aeration for effective composting. We will follow the Minnesota Extension guidelines for establishing an effective pack. The initial pack will consist of three distinct layers in order to promote proper airflow, provide a beneficial host of bacteria and microorganisms, and create dry bedding conditions. The bottom six inches of pack will be woodchips. The woodchips provide proper airflow and allow for good drainage. Above the woodchips, a 2-inch layer of compost will be added. This layer of compost will inoculate the pack with the microorganisms and bacteria necessary to break down the waste and bedding. On top of the compost, a foot of wood chip will be added. By ensuring the proper functioning of the pack prior to the experiment, we can remove pack failure and pack variability as variables from the study.

    We will divide the barn in half, with one half of the barn receiving a control treatment of woodchips and the other half receiving an experimental treatment (either peanut hulls, shredded paper, or a mixture). We will stick with each experimental treatment for 4 months. The pack will be tilled to 10”twice daily – during morning and evening milkings - using a c-tine cultivator pulled behind a Ford 9-N. Bedding material will be added as needed to each quadrant while the pack is being tended.

    Every Saturday, we will collect data to measure the effectiveness of the bedding material in the pack. We will use temperature to assess biological activity in the pack and to determine whether the bedding is being fully composted. Temperature is critical to the breakdown of the pack into compost and indicates the level of biological activity. The ideal temperature range for the pack is 130-150 degrees, but previous studies have shown that the average is 108. At 108 degrees, the pack is not fully composting. Through measuring the temperature of the pack, we will be able to infer the level of biological activity and determine whether there is a difference in biological activity between bedding materials. Using the temperature data, we will perform a Chi-Squared test to determine whether any measured difference is statistically significant between the different types of bedding materials.

    We will also measure cow activity on the pack to assess whether the animals show a preference. By tracking the frequency and activity type in each half of the barn, we will be able to gauge cow preference for the bedding material. Tracking cow frequency on the halves will also be crucial for the financial analysis given the potential for replenishment costs.

    Over the course of the year, we will collect data on the pack 52 times. We will clean out the barn in early May and incorporate the compost into our fields. We will then restart the pack, using the method described above. Cow activity will be classified into three categories: lying down, standing, and eating.

    In order to best apply the nutrients to the field, we will need to conduct nutrient analyses on the bedding. We will take nutrient samples of the barn and submit them to the Cornell Nutrient Analysis Lab for nutrient analysis. Nutrient analysis is a critical component of this project because the composted pack needs to be provide available nutrients to plants in the field. We will use a composite sampling method to analyze the C:N ratio, pH, percent solids, percent organic matter, and total nitrogen, nitrate, potassium, and phosphorous content of the pack. We will create a composite sample for each half of the pack every two months. We will create a composite by collecting one liter of pack material from 12” below the surface from each of the five temperature sampling locations; we will then mix these five samples in a bucket, isolate one liter of the combined sample, and send the sample to the Cornell Nutrient Analysis Lab which will perform the nutrient analysis. We will track the results to determine whether there is an optimal composting duration after which it makes sense to spread. We will also perform a Chi-Squared test to determine whether the different bedding produces statistically significant differences in the nutrient makeup of the pack; while the Chi-squared test will not be very robust, it will provide a springboard for future inquiry. We will also graph the nutrient content of the composted bedding in each half against the acceptable nutrient parameters and note any deviations.

    In addition, tracking the nutrient composition of the composted bedding will allow us to measure the health of the pack and to determine whether all bedding types have an acceptable nutrient profile for spreading.

    The financial analysis provides the linchpin for this study. We hope to identify bedding material that is more cost efficient than wood chips or sawdust. The different bedding materials have different characteristics that will affect how they perform both as bedding material and as compost. In order to perform the financial analysis, we will track both the unit cost of the bedding and the quantity of bedding that we use. We will also try to capture the externalities of the different bedding types in our financial analysis. To do this, we will track the time, fuel, and vehicle maintenance required to maintain the pack. We will also track disease incidence, including hock lesions, mastitis, and lameness, amongst our cows in order to capture the cost of vet bills caused by bedding conditions. If the cows show a preference for a particular type of pack material, we will have to factor this preference into the financial analysis because the preference will affect the rate of bedding replenishment.

    The goal of this study is to find affordable alternative sources of bedding. In order to perform a financial analysis, we will keep records of the quantity and frequency of bedding that needs to be applied to the pack. Through tracking our costs, we will be able to determine which material is the most cost effective bedding. 

    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.