Code of Maine Rules › 01 - DEPARTMENT OF AGRICULTURE, CONSERVATION AND FORESTRY › 001 - AGRICULTURE - GENERAL › Chapter 565 - Nutrient Management Rules › ATTACHMENTS › Attachment F - Best Management Practices for Animal Carcass Composting

Current through 2024-29, July 17, 2024
BEST MANAGEMENT PRACTICES FOR ANIMAL CARCASS
					 COMPOSTING
Bill Seekins
Maine Department of Agriculture
October, 2011
Introduction
Maine's Animal Carcass Disposal Rules, Chapter 211, allow
					 for the use of composting as a method for managing animal carcasses generated
					 on farms and farm operations. (The rules also apply to composting of pets and
					 other domestic animals.) When the rules were drafted and adopted in 1996,
					 composting was applied primarily to poultry and other small animals. As a
					 result of the Foot and Mouth Disease outbreak in Great Britain in 2001 and
					 other disasters that left hundreds or even thousands of large animal carcasses,
					 there has been interest in extending this methodology to larger animals.
Research and demonstration work has been conducted in Maine
					 and in several other states since that time. Work by the Maine Compost Team
					 (see references) demonstrated that large animal carcasses can be successfully
					 composted using a variety of compost feedstocks. The research led to the
					 development of the approach called 'Pre-condition and Turn' which has been
					 tried on a variety of different carcass types. This work has shown that
					 composting is a feasible and in many cases a preferable approach to managing
					 larger carcasses. In many situations, burial is discouraged due to shallow
					 soils or water tables near the surface or due to any number of other factors
					 that render a site unsuitable for burial. Often, these same sites may be used
					 for composting. One advantage often cited is the ability to reuse the compost
					 site over and over, unlike burial sites which should not be used again for many
					 years.
The 2011 update to Chapter 211 contains references to a
					 number of carcass composting techniques and sets standards for siting and
					 operation of each. This document contains the basic information on materials
					 and pile construction and management techniques needed to properly implement
					 several of these composting approaches. Special attention is given to the
					 technique that is referred to as the 'Pre-condition and Turn Method' since that
					 appears to be the most versatile method of composting animal carcasses and
					 applies to the widest range of circumstances. Two other techniques, the static
					 pile and the turned windrow, are also discussed. Information on how to set up
					 and manage a Maryland Bin system is also described. Anyone interested in
					 pursuing that approach will find more detailed information available in
					 publications listed in the Bibliography.
This set of best management practices (BMPs) is the
					 accumulation of information about composting techniques that have been found to
					 be environmentally sound, economical to implement and are unlikely to result in
					 significant nuisance problems if carried out properly. As with any new area of
					 research and demonstration, there is still much to be learned about this
					 process, so that updates of these BMPs are likely over time.
Definitions
Animal Carcass(es)
- Body(ies) or body parts
					 of dead animals, including but not limited to pets, livestock and poultry.
					 Carcasses may be mixed with manure and bedding or other organic materials which
					 cannot be separated from the animal carcasses.
Animals/ carcasses, Large
- Animals such as
					 cows and horses weighing 500 lbs or more.
Animals/ Carcasses, Medium-size
- Animals such
					 as sheep, goats and deer weighing between 100 and 500 lbs.
Animals/ carcasses, Small
- Animals which
					 weigh 100 lbs. or less.
BMP - Best Management Practice
- The term
					 "Best Management Practice," or BMP, originated in the Clean Water Act of 1972,
					 and is now commonly used in the language of environmental management. In
					 agriculture, these are practices,
methods
or
techniques
that have been found by the Commissioner of
					 Agriculture to be the most
effective
and
practical
means
in achieving
					 an objective (such as preventing or minimizing pollution or negative impacts on
					 human or animal health) while making the
optimum
use
					 of the
farm's
resources
.
BMP, General
- Best Management Practices that
					 have been approved by the Commissioner of Agriculture for general use. A list
					 of general BMPs serves as a menu of acceptable options that the farmer,
					 business owner or individual may choose from. Not all general BMPs would apply
					 to any specific situation.
BMP, Site Specific
- Best Management Practices
					 that are developed or approved by the Commissioner of Agriculture to resolve
					 specific problems based on the conditions observed on a particular site.
Bulking Agent
- Relatively dry porous material
					 used to give a compost pile structure and to absorb moisture. Most bulking
					 agents are relatively high in carbon and are also a carbon source. Examples of
					 bulking agents are sawdust, shavings, dry animal bedding and straw.
Compost Medium/Material
- The relatively dry
					 bulky organic material that forms the matrix within which carcasses or offal
					 are composted.
Composting
- The biological decomposition and
					 stabilization of organic matter under mostly aerobic conditions of high
					 temperature (120°F or higher). When oxygen, moisture, nitrogen and carbon
					 are available in the right proportions, the degradation generates considerable
					 quantities of heat, reaching temperatures of 130° to 170° F. This
					 sustained high temperature is responsible for the virtually complete
					 destruction of pathogenic organisms and weed seeds in the composted material.
					 The process also results in a humus-like product that has its nutrients in a
					 much more stable form than the uncomposted wastes making it safer and easier to
					 store and use.
Chronic Wasting Disease
-A neurological
					 disease of members of the deer family. (See Transmissible Spongiform
					 Encephalopathy (TSE))
Emergency
- An unexpected occurrence or set of
					 circumstances demanding immediate action, e.g., fire, major disease outbreak,
					 flood, etc. An emergency exists when multiple carcasses result from a single,
					 unplanned occurrence, such as a fire, disease outbreak, flood or other
					 disaster.
Offal
- Unwanted or unused body parts
					 remaining from butchering or slaughtering animals.
Scrapie
- A neurological disease of sheep and
					 goats. (See Transmissible Spongiform Encephalopathy (TSE))
Transmissible Spongiform Encephalopathy (TSE)
- One of several similar neurologic diseases thought to be caused by a
					 mis-folded protein (prion) in the nervous tissue which results in slow
					 degeneration of the nervous system and ultimately in death. These diseases
					 include Scrapie, 'Mad Cow Disease' and Chronic Wasting Disease.
Applicability
.
The primary approach described in this document is the
					 'pre-condition and turn' method of composting that has been developed as a
					 result of the research noted above. This approach is suitable for composting
					 large animal carcasses as well as smaller animals. It may also be adapted for
					 composting animal parts such as those generated from slaughterhouses and
					 butcher shops. The pre-condition and turn approach is well suited to either
					 routine disposal or large scale disaster disposal situations. Although the
					 other methods described may be used in all these situations, each has certain
					 limitations in some scenarios. For example, the Maryland Bin System would be
					 impractical to set up in an emergency situation since there would not be time
					 to pour cement and construct enough bins to handle a large mortality event. On
					 the other hand, the turned windrow system does not lend itself well to
					 composting large carcasses unless they have been cut into smaller pieces that
					 can be mixed with a compost medium and turned. In instances where the carcasses
					 are the result of a disease outbreak, certain materials and methods are
					 preferred over others. These will be identified in the sections addressing
					 these items.
Description of Composting Systems
Several compost systems are available. The most common are
					 the University of Maryland Compost Bin System, the turned windrow system, the
					 aerated static pile system, the pre-condition and turn system and in-house
					 composting. A less common approach is the use of some type of in-vessel
					 system.
a.
University of
				  Maryland Bin System
- The University of Maryland Bin Composting System
				  uses wooden or concrete block bins to compost poultry, other small carcasses or
				  poultry offal. The composting is done in two active stages plus a curing stage.
				  This system only applies to small carcasses or small body parts. (Other bin
				  systems are also possible.)
b.
Turned Windrow
- The turned windrow system is an approach, in
				  which the compost mixture is placed in rows and turned periodically during the
				  compost cycle. The turning action supplies oxygen through gas exchange, thereby
				  creating natural ventilation. The frequent turning insures the production of a
				  uniform product at the end of the compost process. Success with this system
				  depends on the ability to achieve a thorough mix and aeration through repeated
				  turning. This system only applies to small carcasses, small body parts or
				  ground carcasses.
c.
Static
				  Pile -
The static pile method uses a pile of composting material that is
				  not agitated or turned. The initial thorough mixing of the carcasses or body
				  parts with the compost media is essential to create a uniform mix and contact
				  between all carcasses and the media. Porosity in the pile must be sufficient to
				  allow proper air flow and effective composting. Aerobic conditions are
				  maintained by natural ventilation of the pile that is enhanced by using
				  materials that maintain relatively high pile porosity. The pile is covered with
				  an insulating blanket of four to six inches of finished compost, compost media,
				  or other suitable material to ensure proper temperatures are attained at outer
				  edges of pile. This approach applies primarily to poultry and other small
				  carcasses.
d.
Aerated Static
				  Pile -
In the aerated static pile method (also known as the Beltsville
				  Method or Rutgers Method), the compost is not agitated or turned. The initial
				  mixing of the carcasses with the bulking agent must be sufficient to allow
				  proper air flow and effective composting. Aerobic conditions are maintained by
				  mechanically drawing, or blowing air through the pile. The pile is covered with
				  an insulating blanket of four to six inches of finished compost, compost media,
				  or other suitable material to ensure proper temperatures are attained at outer
				  edges of pile. This approach applies primarily to poultry and other small
				  carcasses.
e.
Precondition
				  and Turn Method
- The pre-condition and turn system was developed
				  specifically for management of animal carcasses and slaughterhouse wastes.
In this method, the carcass or body parts are placed
					 between layers of dry absorbent bedding or other compost media. The carcasses
					 or body parts are then allowed to decompose without disturbance for a period of
					 time, which varies with carcass size and other factors. (See Table 1.) Once
					 this pre-conditioning period is done, the pile or windrow is then turned
					 similar to the turned windrow system. This method may be used for both routine
					 and emergency situations and for both large and small carcasses and
					 slaughterhouse wastes (offal) of all types. It has the advantage that early in
					 the process, the carcasses or offal remain buried deeply in the compost media
					 until a significant amount of decomposition has occurred. This significantly
					 reduces nuisances in these early stages, but allows the advantages of thorough
					 mixing and aeration in the later stages.
f.
In-house Composting -
This
				  option uses one of the windrow or pile based compost methods such as the turned
				  windrow or the pre-condition and turn approaches except that the windrow or
				  pile would be formed inside the barn using the litter from the barn and,
				  usually, some additional bulking agent as the compost medium. This approach
				  applies primarily to poultry that are raised on the floor of the poultry barn
				  with litter although it could also be used for other small or medium size
				  animals kept in loose housing.
g.
In-vessel Composting -
Many different in-vessel compost systems
				  have been developed for a variety of purposes. Some are static systems with air
				  introduced with blowers. Others are mechanically agitated or tumbled to mix and
				  aerate the contents. The common factor in all these systems is that the
				  composting is done within a container. Several compost systems that incorporate
				  some type of vessel in the compost process are available. Most of these systems
				  use some form of active aeration to provide the needed oxygen. One system that
				  has been used to compost poultry mortalities from an avian influenza outbreak
				  utilized the large plastic 'bags' designed for feed storage with aeration tubes
				  inside. These systems offer the advantage that they are completely enclosed and
				  so promise greater control over odors, vectors and loss of leachate than open
				  windrow methods. Most of these systems are best suited to small carcasses or
				  carcasses that have been ground or cut into pieces.
Siting Carcass Compost Operations
Because carcass composting has the potential to impact the
					 environment, most states have standards for locating carcass compost sites. The
					 standards include setback distances to sensitive features such as water bodies
					 and separation distances to groundwater and bedrock. Maine's standards are
					 spelled out in Tables 4 through 8 at the end of the Chapter 211 Rules.
					 Composters are advised to check with the standards for their own state prior to
					 establishing a carcass compost site. Here is some general guidance in siting a
					 compost facility:
1. Excess water is
				  the composter's enemy. Setting up your site to be sure that the compost is
				  never sitting in water and that your equipment is not working in mud is a key
				  to successful composting.
2. The
				  soil or other working surface should have a minimum slope of 2 percent and a
				  maximum slope of 6 percent that slopes to move water off from the site rather
				  than let is stand. Sites on natural soils need to have a little more slope than
				  paved sites since ruts are more likely on the soil surface.
3. Composting sites should be located as near
				  the source of carcasses as practical and in accordance with the regulatory
				  setback requirements. (For Maine composters, the requirements are laid out in
				  the Carcass Disposal Rules, Chapter 211.) Whenever possible, the siting should
				  also be done so that the prevailing winds will not carry odors from the site to
				  nearby neighbors.
4. Surface water
				  should be diverted away from the facility.
5. The compost pad and any area surrounding
				  it that will have equipment traffic should be designed so that it can handle
				  traffic involved in the compost process.
6. You should have a vegetated filter strip
				  or other approved area downslope from the compost pad to receive and treat any
				  leachate or runoff that might be generated.
Space Requirements
Once a potential compost site has been identified, the
					 amount of space required to accommodate the number of carcasses should be
					 calculated. See Diagram 1 for guidance in doing this calculation for large
					 animal carcasses. For medium size carcasses, assume that the space requirements
					 per animal will be about half those for a large carcass. Space requirements for
					 small carcasses should be based on an animal unit basis, where each 1000 lbs of
					 small carcasses is the equivalent of one animal unit. The guidance in Diagram 3
					 may be used to estimate space for small animal carcasses by replacing one
					 carcass with one animal unit. Once this is done, the site should be checked to
					 be sure sufficient space is available. If it is not, an additional area(s) will
					 need to be identified.
Materials/ Compost Media for Animal Carcass and Offal
					 Composting
The media used for composting carcasses or offal should
					 provide the conditions that will support hot aerobic composting
Characteristics
: Animal carcasses
					 and offal can be successfully composted in a variety of media. The ability to
					 achieve temperatures proven to kill most pathogens will depend more on the
					 conditions in the media than on the source of the media. Those conditions that
					 appear to be most conducive to rapid and sustained heating are:
a. Porosity - The compost media should have
				  sufficient porosity that it will allow air to be drawn into the pile through
				  natural ventilation but not so porous as to cause excessive drying or cooling.
				  Piles with a predominance of very fine textures or very wet materials fail to
				  heat due to lack of oxygen. Piles with a very high porosity, such as wood
				  chips, heat rapidly but are unable to sustain the high temperatures. Mixtures
				  having a large proportion of particles between 1/8 inch and one inch appear to
				  give the optimum results.
b. C:N
				  ratio - As with all composting, piles with C:N ratios too high (over 40:1) tend
				  to heat slower than those with a lower C:N. In order to accommodate the
				  nitrogen from the carcass, the C:N ratio in the compost media should be between
				  25:1 and 50:1, with the preferred range being between 25:1 and 40:1.
c. Moisture - The compost media should have a
				  moisture content between 40 and 65% with the preferred range being between 50
				  and 60%. This may be assessed through the use of the squeeze test or other
				  acceptable test procedures. A material that is so wet that water will run out
				  when squeezed is not likely to aerate well and will result in anaerobic
				  conditions in the pile.
d.
				  Biological activity - The compost media should be biologically active such that
				  it will reach temperatures of at least 120°F when placed in a pile at least
				  6 ft (two meters) in diameter and 3.5 ft (one meter) high. Materials such as
				  sawdust or woodchips that have limited biological activity and will not heat on
				  their own should be amended with other ingredients (such as manure or waste
				  feed) to create a biologically active environment.
e. Age of material - The compost media for
				  carcass composting should be fresh, active material. Materials that have been
				  composting for several months do not have the amount of energy or activity
				  needed to sustain the temperatures within the carcasses when compared to
				  relatively fresh active compost piles.
Compost Media Recommendations for Animal Carcasses. The
					 following media have been tested and found to give excellent results for
					 composting animal carcasses and offal:
hot municipal sludge compost
													fresh dry horse bedding
													mixture of waste feed ( 1/4 to 1/3 of the mix) and
						dry horse, heifer or calf bedding(2/3 to 3/4 of the mix)
													mixture of fresh fall leaves and poultry manure (in a
						ratio of 10 to 1 leaves to manure)
NOTE: Hot municipal sludge compost is recommended in
					 emergency situations in the State of Maine since it is readily available in
					 large quantities and has been proven to create the conditions necessary to
					 compost both large and small carcasses.
Any other media that meets the requirements in the section
					 above should also perform well for composting either carcasses or offal.
Compost Management
Processes
. Several compost systems
					 or processes are discussed in this document. The process recommended for most
					 situations may be described as a static compost pile followed by the turned
					 windrow method. In Maine, this has been named the 'Precondition and Turn
					 Method' of composting. In this system, a large carcass or carcasses would be
					 placed in a pile of actively composting material and allowed to decompose
					 undisturbed for up to 10 to 12 weeks. (This can be shorter if investigation of
					 the pile shows that very little soft tissue remains.) Other systems discussed
					 in later sections include the static pile system, turned windrow system, the
					 Maryland Bin System, in-vessel composting and in-house composting.
Turning
. Compost piles are often
					 turned to mix the various ingredients and to introduce air space to allow for
					 aeration. This may be done with a tractor or other piece of equipment with a
					 loader. Compost turning machines that are designed specifically for this
					 purpose are also available. Turning may be problematic early in the compost
					 process because of the difficulty of moving the carcasses while keeping them
					 properly covered. Many compost turners would not be able to turn an object the
					 size of a large farm animal while it was intact. After turning, care should be
					 taken to make sure there is no soft tissue on the surface of the pile. Bones on
					 the surface of the pile with any soft tissue should be reburied in the compost
					 pile immediately. (Note: Static pile systems and many in-vessel systems do not
					 include turning as part of the process.)
Odor, Insect and Vector Control
.
					 Animal carcass compost sites and operations should be managed to minimize odors
					 and the attraction of insects and other vectors. The first step toward doing
					 this would be to make sure no carcass is left uncovered long enough to attract
					 vectors. Generally, if carcasses are covered within 6 hours vector attraction
					 will be minimal. Offal, however, is more odorous so that it attracts vectors
					 quicker and should be covered as soon as possible. (Note: Maine's carcass
					 disposal rules, Chapter 211 require that carcasses be covered within 24 hours
					 and that offal be covered within four hours.). Proper pile construction with
					 sufficient material both below and above the carcass is critical. (See pile
					 construction section.) Good pile management and good housekeeping are also very
					 important. As the carcass(es) decomposes, especially within the first 5 or 6
					 days, the pile is likely to settle dramatically. It is essential to check the
					 pile and re-cover any part of the carcass(es) that may become exposed. The
					 settling process may also create cracks in the material, especially just above
					 the carcass(es). These cracks should be filled since they can form channels for
					 odor to escape the pile, attracting insects, birds, dogs and other
					 scavengers.
In some cases, it may be necessary to discourage animals
					 such as turkeys, dogs or coyotes from digging in fresh piles. Draping the
					 orange plastic 'safety fencing' over freshly built piles has proven to be an
					 effective deterrent to digging.
Types of Carcasses
. Compost
					 techniques have been successfully used with adult cattle, calves, horses, pigs,
					 sheep, poultry and other less common types of farm animals. Some work has also
					 shown success with composting large marine mammals. At this time, composting is
					 not being recommended for the disposal of animals showing symptoms of
					 neurological diseases such as Chronic Wasting Disease or Scrapie. Research is
					 currently being done to assess the extent of destruction of the causal agent
					 for these types of diseases so this recommendation may change in the
					 future.
Carcass Preparation
. In general,
					 no preparation is necessary for the most compost systems to work. In many cases
					 there are a couple of steps that may be taken to enhance the composting
					 process.
1. Venting the abdomen of
				  large animals helps reduce bloating and so reduces the chance of exposure of
				  parts of the carcass in the first few days of the compost process. For cattle,
				  effort should be made to vent the abdomen in several places since a single vent
				  hole will not release gas from all parts of the abdomen.
2. Some farms have reported that cutting a
				  large carcass, such as a dairy cow in half or quarters speeds up the
				  decomposition process. A modification of this would be to split open the
				  abdomen to allow more contact with air and the compost mixture.
Neither venting nor cutting is required for the overall
					 success of this process. In the case of carcasses with highly contagious
					 diseases, such as Foot and Mouth Disease, it is recommended that the carcasses
					 not be vented or cut in order to minimize the chance of transferring the
					 disease organism.
If large or medium size carcasses are to be composted using
					 a turned windrow system, then grinding the carcasses or reducing them to
					 smaller pieces in some way is highly recommended. Otherwise turning will be
					 very difficult at the outset.
Pile Construction and Management
.
Proper pile construction is a key to composting animal
					 carcasses without causing environmental problems or nuisances. Diagrams 2 and 3
					 illustrate the recommended approach to constructing compost windrows for large
					 animal carcasses. Diagrams 4 through 6 illustrate the recommended layout for
					 medium size carcasses, small carcasses and offal, respectively. Diagrams 7
					 through 9 illustrate the layout for Turned Windrow, Static Pile and Maryland
					 Bin systems.
Taking Temperatures
Systematically taking and recording temperatures is an
					 important tool in managing any kind of compost pile. Here are the MAINE COMPOST
					 SCHOOL RECOMMENDATIONS for taking pile temperatures:
1. For a Windrow:
TAKE 5 OR MORE READINGS FOR EACH WINDROW
READINGS SHOULD BE EVENLY SPACED ALONG THE WINDROW
RECORD INDIVIDUAL READINGS AND AVERAGE FOR THE WINDROW
TAKE READINGS FROM SAME LOCATIONS EACH DAY!
2. For a Round Pile:
TAKE 2 OR MORE READINGS
READINGS SHOULD BE FROM OPPOSITE SIDES OF PILE
RECORD INDIVIDUAL READINGS AND AVERAGE FOR THE PILE
TAKE READINGS FROM SAME LOCATIONS EACH DAY!
3. At each location, TAKE
				  TEMPERATURES AT DEPTHS OF
1 FOOT (30 cm) - HOTTEST LEVEL
3 FOOT (1 meter) OR CORE
RECORD TEMPS AT EACH DEPTH SEPARATELY
You should record the pile temperatures as often as
					 possible, preferably every day you are on the compost site. Keep in mind that
					 you will need to keep records at least until a pile meets the time/temperature
					 requirements in CHAPTER 211. In addition to pile temperatures, you should
					 record management information such as pile turning or addition of water or
					 other ingredients. To complete the record, you should keep track of any
					 rainfall or other significant weather event that has happened since the last
					 time temperatures were recorded. This will help in interpreting your
					 temperature data when you look at it at a later date.
Meeting Time/Temperature Standards
.
In order to distribute compost made from animal carcasses
					 to the public, the compost process must meet certain time and temperature
					 standards. These standards differ depending on the type of compost system being
					 used. Maine's time/temperature standards as laid out in Chapter 211 are as
					 follows:
1.
Maryland
				  Bin Composters -
: Temperature shall be monitored and recorded on a daily
				  basis at least until the time/temperature standard has been met. Temperature
				  readings shall be taken at a point near the center of the bin. The compost
				  shall attain a minimum temperature of 131° F (55° C) for a minimum of
				  one day in Stage I and for a minimum of three days in Stage II. Batches that
				  fail to meet this temperature requirement shall be incorporated into subsequent
				  batches and re-composted or be spread on the owner's land;
2
Windrow Composting Method
-
				  Temperature shall reach a minimum of 131° F (55° C) for at least 15
				  days during the composting period. During the high temperature period there
				  must be a minimum of five (5) turnings of the pile. Once this temperature
				  requirement is met, the windrow shall be turned at least once per week. Once
				  the temperature in the windrow drops below 110°F and does not increase
				  after turning, the windrow may be placed in a curing pile.
3.
Static Pile or Aerated Static
				  Pile.
The pile shall be maintained at a temperature of 131° F
				  (55° C) or greater for at least three (3) days at both the three foot and
				  one foot depths in the pile. Detention time in the static pile or aerated
				  static pile shall be at least 21 days, after which the pile may be dismantled
				  and moved to curing;
4.
Pre-Condition and Turn Method
. The compost shall attain a minimum
				  temperature of 131° F (55° C) at the three foot depth at each location
				  for a minimum of three days in the pre-condition stage (Stage I) or for a
				  minimum of fifteen days at either depth during the turning stage (Stage II).
				  The windrow must be turned at least five times during the high temperature
				  period.
5.
In-vessel Compost
				  Systems
. The contents of the vessel shall be maintained at a temperature
				  of 131° F (55° C) or greater for at least three (3) days throughout the
				  vessel. The composting mixture shall remain in the vessel until all soft tissue
				  is gone but in no case shall it be retained for less than 21 days, after which
				  the contents may be removed to a compost pile or placed in curing;
Minimum Volumes
For all composting methods other than the Maryland Bin
					 System, a minimum pile volume of five (5) cubic yards is required for the
					 process to be effective. Piles with larger carcasses will, of course, require a
					 much larger volume in order to adequately cover the carcass (es). See the pile
					 construction diagrams at the end of this document for guidance in estimating
					 volumes needed.
Curing
For all compost systems, the compost should be cured for
					 three (3) to six (6) months once the active compost phase has been completed or
					 after the pile has cooled to less than 110°
F(43°C). Compost that is to be field applied may be
					 utilized immediately after the active compost stage or may be cured for a
					 shorter time before use.
Pre-condition and Turn Method Step by Step
					 Process
Step 1. Lay out a bed of dry compost media mix. It is
					 important to make sure there is at least 18 inches of dry absorbent material
					 below the carcass. This minimizes the amount of fluids that are released as the
					 animal decomposes from reaching the ground water or exiting the pile. The bed
					 of material upon which the carcass is laid, should extend at least two feet
					 beyond the carcass in every direction. For most dairy cows, this would require
					 a bed about 8' by 10' - 12'. The size will need to be adjusted based on the
					 size of the carcass.
If multiple carcasses are to be composted at the same time,
					 the base of a windrow can be formed by creating a bed about 8 to 10 feet wide
					 and as long as needed to accommodate the number of animals to be composted. See
					 Diagram 1.
Step 2. Place the carcass on the bed of compost material.
					 The carcass should be laid on its side to reduce the chance that the legs will
					 be exposed as the pile settles. For a single animal, the carcass should be
					 oriented so that the length of the body is going lengthwise of the pile.
If multiple carcasses are to be composted at the same time,
					 a windrow can be formed. It is recommended that carcasses be laid at right
					 angles to the orientation of the windrow and placed so the body of one overlaps
					 the legs of the adjacent carcass. This helps reduce the overall length of the
					 windrow needed and the amount of compost material needed. See Diagram 1.
Step 3. Prepare carcass, if desired. This is the most
					 convenient point in the process to vent the carcass, open it up or to insert a
					 thermometer, if any of those steps are to be taken.
Step 4. Cover carcass(es) with at least two feet of compost
					 material. To be sure that at least two feet of cover is present over all parts
					 of the carcass, the equipment operator or preferably someone working on the
					 ground should probe all parts of the pile to determine how deep the carcass is
					 buried. A three foot long compost thermometer makes a good probe, as does a
					 length of sharpened steel rebar. Any type of rod that is at least three feet
					 long and has a tapered end will work.
When composting carcasses in the winter, additional cover
					 material will be needed to maintain pile temperatures. An additional six to
					 twelve inches of cover material will insulate the pile and allow the core of
					 the pile to stay warm and active for much of the winter.
Step 5. Monitor the pile regularly, especially for the
					 first 4 or 5 days. An active carcass compost pile will change dramatically over
					 the first week of composting. Piles often settle a foot or more and sometimes
					 develop cracks that can lead to odors and attract animals and insects to the
					 pile.
Step 6. Maintain the pile as needed. If a crack appears in
					 the pile or if any of the carcass becomes exposed, or if there is any animal
					 activity, the pile will need to be repaired. This usually consists of either
					 raking material into the cracks or adding more material to cover exposed parts
					 and to discourage scavengers. Any of these conditions should be corrected as
					 soon as possible since they can lead to greater problems if left
					 uncorrected.
Step 7. Pre-condition the carcass(es). To do this, allow
					 the pile to compost undisturbed for several days to several weeks depending on
					 size and type of carcass or offal. See the table below for suggested lengths of
					 time for different carcass types. The pile may be left for up to six months if
					 turning is impractical at the end of the pre-condition period. Some piles may
					 be ready to turn in shorter time. This can be determined by digging into the
					 pile to determine the level of decomposition. The length of the pre-condition
					 period can vary considerably based on the level of energy in the compost
					 medium, the size of the carcass and the time of year.
TABLE 1 SUGGESTED LENGTH OF PRE-CONDITION
					 PERIOD FOR CARCASSES AND OFFAL
Type of
								Material
Length of Pre-condition
								Period
(Days)
Poultry offal
7 to 10
Large animal offal
20 to 25
Large animal offal with bones
25 to 40
Poultry and other small carcasses
25 to 35
Deer, goats, sheep and mid size carcasses
35 to 45
Cows, horses and other large carcasses
40 to 90
Note that these suggested pre-conditioning time periods are
					 based on the use of an active, hot compost medium. Pre-conditioning times may
					 increase dramatically if the medium is old, wet, extremely dense or otherwise
					 inhibited in activity.
Step 8. Turn the pile or windrow. The pile or windrow may
					 be turned with a bucket loader, excavator or any other piece of equipment that
					 will lift, fluff and mix the material. A compost turning machine would be ideal
					 for this purpose. Turning should be done about once a week for as long as the
					 average pile temperature is above 110° F. At least two turnings are
					 recommended even if the temperatures are below 110° F when it is time to
					 turn the pile or windrow for the first time. For more detail on determining
					 turning schedules, see the section on Aeration for Turned Windrows.
Step 9. Cure the compost. Once the pile has cooled to less
					 than 110° F (43°C), it may be placed in a larger stockpile to cure.
					 Curing normally takes from 3 to 6 months after the active compost stage is
					 done. Compost that is to be field applied may be cured for a shorter time or
					 applied immediately after the active composting stage.
Turned
					 Windrow
.
In general, a turned windrow system is not recommended for
					 fresh whole large or medium size carcasses for a number of reasons. A turned
					 windrow may be used, however, if grinding equipment with sufficient capacity to
					 handle a whole carcass is available. A turned windrow may be used for smaller
					 animals such as chickens since it may be possible to mix them with the compost
					 media and then be turned on a regular basis. In order to avoid nuisance and
					 vector problems, it would be necessary to pick up any carcasses that fall out
					 of the windrow during turning and then re-bury them in the compost media. The
					 windrows may have to be re-covered with compost following the first few turns
					 to make sure that all carcasses are buried deeply enough in the pile. This
					 extra work of repeated burying and covering makes the turned windrow system an
					 unattractive option for most farms. (See the On-Farm Composting Handbook for
					 details on managing a turned windrow compost system.)
Mixing for Turned Windrows.
The
					 mixing of ingredients in a turned windrow may be done in two ways. If a mixing
					 device such as a feed mix wagon is available, the compost materials may be
					 premixed prior to forming them into a windrow. This approach is preferred for
					 carcass composting since the carcass(es) can be buried in a fully mixed medium
					 at the start. If no mixing device is available, the ingredients can be laid out
					 as in Diagram 7 and then mixed with a bucket loader or windrow turner.
Pile Construction for Turned
					 Windrows.
Windrows that will be turned may be laid out the same as
					 those that will be managed using the pre-condition and turn system. See
					 Diagrams 2 through 6 for windrows built using a pre-mixed compost medium. Or
					 they may be laid out as in Diagram 7 if the ingredients in the medium are not
					 going to be pre-mixed.
Aeration for Turned Windrows.
Aeration in a windrow system in general occurs as a result of the natural
					 intake of air along the sides of the windrow as the pile heats and vents the
					 hot air out the top of the windrow. The ease with which this happens depends on
					 the porosity of the compost medium. As the windrow or pile composts, it
					 settles, thus increasing compaction and reducing porosity. Periodically, it
					 necessary to fluff up the compost material to re-introduce the air space into
					 the pile to allow it to continue to 'breathe'. This can be done by lifting and
					 fluffing the material with a loader of some type or by turning it with a
					 compost turner.
The frequency of turning in a turned windrow system can be
					 determined based on time or on temperature. The initial turning schedule,
					 however, may be determined by the need to meet certain regulatory requirements.
					 In Maine, the Chapter 211 rules require that carcass compost being managed by
					 the turned windrow method must achieve a temperature of 131° F
					 (55°C).for a minimum of 15 days and that it will be turned at least five
					 times while the temperature is at or above 131° F (55°C).
After this regulatory requirement has been met, the windrow
					 or pile will still need to be turned periodically in order to facilitate the
					 aeration process and maintain pile temperatures. Generally, if a windrow is
					 turned once a week as long as temperatures remain at or above 110° F, the
					 aeration needs will be met.
Those who want to base turning on temperatures may use the
					 following rules of thumb to guide turning decisions:
Turn whenever there is a significant drop in pile
						temperature from one day to the next and no external cause is
						apparent.
														Turn whenever the pile temperature exceeds some
						temperature threshold. An example might be to turn any time the temperature
						exceeds 160°F.
														Turn if the temperature reading at the one foot depth
						in the pile is more than twenty degrees F hotter than the three foot
						temperature.
														For additional details on how to construct and manage
						a Turned Windrow System refer to the 'On-farm Composting Handbook'.
Curing
. Curing in a turned windrow
					 system is similar to curing in the precondition and turn system. Once the pile
					 has cooled to less than 110° F (43°C), it may be placed in a larger
					 stockpile to cure. Curing normally takes from 3 to 6 months after the active
					 compost stage is done. Compost that is to be field applied may be cured for a
					 shorter time or applied immediately after the active composting stage.
Static Pile and Aerated Static Pile
Mixing for Static Piles
Thorough up-front mixing of the compost ingredients is
					 essential for success in static compost systems since the material remains
					 undisturbed throughout the active composting phase of the process. This means
					 that the ingredients must either be placed in a mixing device in the right
					 proportions (see section on compost media) or layered in the right proportions
					 and mixed with a loader. For static pile systems, a mixing device such as a
					 feed mix wagon is highly recommended since a much more uniform mixture can be
					 created than with a bucket loader.
Pile Construction for Static
					 Piles
Once a thorough mix of ingredients, including the carcasses
					 or parts, has been achieved, they should be laid out as shown in the Diagram 8.
					 It is important that once the pile has been formed, a layer of compost, compost
					 media or other dry bulky material be placed over the mixture. This layer not
					 only insulates the pile allowing it to heat throughout, but acts as odor
					 control. If sufficient cover material is not used, animals are likely to be
					 attracted to the piles.
Aeration for Static Piles
Aeration for static piles may be either passive or active.
					 The difference is that in active aeration, a blower would be used to blow or
					 draw air through the compost mixture, while passive aeration depends on the
					 natural flow of air in the pile caused by the heating of the material.
Passively Aerated
Passive aeration depends on the pile maintaining sufficient
					 porosity throughout the compost process to allow the pile to naturally draw air
					 in through the pile sides. In order for this to happen, the original mix must
					 be made up of materials that will resist compacting as the pile settles and
					 reduces in size. Generally, this means that there are components such as wood
					 chips or coarse wood shavings that will continue to provide air spaces as the
					 process progresses. A relatively low starting bulk density (about 800 lbs per
					 cubic yard) for the mix will also be a benefit. Passively aerated piles may
					 include aeration pipes under the piles to try to improve the amount of air flow
					 in the pile. Results using aeration pipes under passively aerated carcass
					 compost piles has had mixed results. Although early pile temperatures may be
					 higher when using the aeration pipes, they have also led to more odor and
					 vector issues since the pipes can act as conduits for liquids to leave the
					 pile.
Actively Aerated
Actively aerated carcass compost piles would rely on using
					 a similar mixture of ingredients as described in the passively aerated compost
					 pile section above. These systems, however, all have either aeration pipes
					 underneath the pile or an air plenum built into the floor of the compost area.
					 These structures allow air to be blown into the pile mechanically. A key to
					 using an actively aerated static pile is determining the number, size and
					 scheduling for blowers. A common rule of thumb is to design a blower system to
					 deliver approximately 10 cfm (cubic feet per minute) of air per dry ton of
					 composting material based on continuous airflow. (Delivery rate would need to
					 be higher for intermittent aeration schemes.) Blowers for this type of system
					 generally are in the 1/3 to 1/2 hp size range. The 'On-farm Composting
					 Handbook' has details on how to construct and manage an aerated static
					 pile
Length of Time in Pile
Most regulations, including Maine's Chapter
					 211, that determine the minimum standards for carcass composting require that
					 static piles remain undisturbed for 21 days or more. The rules then allow the
					 compost to be moved to curing piles. Experience has shown that meeting this
					 standard will result in pathogen and weed seed kill and will significantly
					 reduce the vector attraction but the composting process is far from finished.
					 Generally, temperatures in the static pile will still be well over 130°F
					 (55°C) at the end of the 21 day period. Longer compost periods are
					 recommended if a stable final product is the goal.
Curing
Curing is especially important for compost produced using
					 either of the static pile systems since experience has shown that the material
					 is not uniformly composted at the end of the nominal active composting period
					 and may contain very immature active material in some locations. Allowing it to
					 cure for three to six months will allow harmful constituents in the immature
					 compost such as ammonia or volatile organic acids to further break down prior
					 to use. For the curing to be effective, however, the compost needs to be moved
					 from the original location and actively mixed and re-piled to allow the various
					 parts of the pile to be homogenized.
Bin Systems.
A permanent bin system may be set up to accommodate routine
					 mortalities on a farm. Generally, bins are sized and used for carcasses that
					 are 300 lbs or less. Some mid-western farm operations, however, have
					 successfully composted cow carcasses using large concrete bins with built in
					 air ducts or temporary bins made from large round bales of hay. The dimensions
					 of the bins should be determined based on the size of the carcasses to be
					 composted and the equipment that would be used to unload the bins. (See
					 reference section for publications about designing, building and managing bin
					 compost systems.) One of the most commonly used bin systems was developed for
					 the broiler industry by the University of Maryland. That system is used
					 throughout the Southeastern United States for the disposal of poultry. Some of
					 the basics are given below. More information on bin design, construction and
					 management may be found in several references in the Bibliography.
Maryland Bin System
The University of Maryland Bin Composting System uses
					 wooden (or sometimes concrete block) bins to compost poultry carcasses. The
					 composting is done in two active stages plus a curing stage. Stage I begins by
					 placing a 6" layer of dry poultry manure in the bottom of a bin then placing a
					 6" layer of straw, chopped hay or other loose bulking material, then poultry
					 carcasses and a layer of manure. The straw, carcass, manure sequence is
					 repeated until the bin is full. (See Diagram 9.) It is then allowed to compost
					 for 7-10 days.
Stage II begins when the material that has been composting
					 7-10 days is moved into a second bin. The moving should be done so as to mix
					 and loosen the material as much as possible.
After the material has been in the second bin for
					 approximately 10 days, the highly active composting period is complete. The
					 material may then be moved to a curing pile for 30 days.
1. Bin Construction - The compost bins must
				  be built of decay-resistant wood or other durable materials. They are built on
				  an impervious base and most have a roof to keep out excess moisture. Plans for
				  bin construction are available from several sources (See Bibliography.)
Bins are typically 5' high, 5' deep and 8'+/- wide, with
					 the width of the bin planned to accommodate the size of the equipment used to
					 load and unload each bin. The second stage, or secondary composter, may consist
					 of individual bins or one bin of the size equivalent to the sum of the
					 individual bins.
2. Bin
				  Volume - For each stage of the composting process, storage volume is calculated
				  as follows:
a. Volume (cf) = Number of birds
				  in flock x Design Factor (See Table 2)
b. Number of bins per stage = volume (from
				  above) (cf)/volume of one bin (cf)
TABLE 2. DESIGN FACTORS FOR SIZING COMPOSTING BINS*
Poultry Type
Design Factor cu. ft./bird
Broiler
0.0105
Roaster
* females
0.0071
* males
0.0214
Laying Hens
0.0035
Breeding Hens
0.0048
Breeders - Male
0.0238
Turkey
* female
0.0196
* tom
0.0468
* feather production
0.0741
*From SNTC Bulletin S210-0-05
3. Operation of Maryland Bin systems
a. Temperature should be monitored on a daily
				  basis. Temperature should peak at 130° to 140° F in each stage of the
				  composting process.
b. At the end
				  of each day that carcasses are placed in the bin, they should be covered with
				  manure and bulking agent to reduce odor, fly and vermin problems.
c. The Compost mixture normally remains in
				  primary (Stage I) bin for a minimum of seven (7) days after bin is filled and a
				  minimum of seven (7) days in the secondary (Stage II) bin. After leaving the
				  secondary (Stage II) bin, the compost should remain in a curing pile for at
				  least 30 days before use or distribution. The material will still be active at
				  this point.
d. To avoid fly and
				  odor problems, carcasses should be placed at least 6" from the sides of
				  composting bins.
e. The compost
				  medium ingredients that are recommended by the University of Maryland age given
				  in the table below. See the section on compost materials for additional ideas
				  for materials that may be used.
f.
				  Moisture in the composting material should be checked periodically and water
				  added if it is not moist to the touch.
Composting Mix Ratio Recommendations for the Maryland
					 Bin System
The mix ratio recommended by the University of Maryland and
					 the Natural Resources Conservation Service is given below in Table 3.
TABLE 3. MIX RATIO RECOMMENDATIONS FOR MARYLAND BIN
					 SYSTEM*
Component
Parts by Volume
Parts by Weight
C:N Ratio
Chicken Manure
1.5
1.2
15:1
Dead Birds
1.0
1.0
5:1
Straw (Bulking Agent)
1.0
0.1
50:1 to 300:1
Water *
*A mixture that has enough moisture (50-65 percent) to feel
					 moist to the touch but not so moist that water can be wrung out should be about
					 right, i.e. it should feel like a "damp sponge" to the touch.
Final Disposition of Compost
Compost produced from animal carcasses or animal body parts
					 may only be distributed to the public if the operation has temperature records
					 to show that the batch under consideration has met the time/temperature
					 standards for the specific composting system being used .(See section 'Meeting
					 Time/Temperature Standards' for a list of these standards.)
Compost that has not met the appropriate time/temperature
					 standard or for which there is no record indicating that it has met the
					 standard may be spread on the owner's own fields. It may also be incorporated
					 into other batches of compost and re-composted in order to meet the
					 time/temperature standard.
Compost that has met the standards may be used for any
					 purpose for which it is suitable based on its agronomic characteristics.
Management of Bones
In most compost piles, the soft tissue from the carcass
					 will disappear much more quickly than the larger bones. This means that the
					 operator must be prepared to manage the bones in the finished product. This can
					 be done by one of the following methods:
1. Grinding the bones/compost mix so that the
				  bone particles become a part of the final product.
2. Screening out the bones from the final
				  product. The separated bones may be buried, added to another active compost
				  pile and re-composted, ground up for use as a calcium-rich soil amendment or
				  even burned.
3. Spread compost
				  including bones on land. The compost product with bones may be spread on forest
				  land or agricultural fields. Consideration should be given to possible impact
				  of large bones on equipment that may be operated on the field in the near
				  future. Experience has shown that if compost with bones is spread on tilled
				  ground, the tillage equipment will break up the bones and incorporate them into
				  the soil. Spreading bones on hay ground, on the other hand, may be undesirable
				  since they can be picked up by the haying equipment.
Monitoring
Visual Inspection. Carcass compost piles should be visually
					 inspected daily for the first week after construction and then at least once a
					 week for the next 10 to 12 weeks. It is important to make sure that any
					 maintenance needed is recognized quickly and taken care of promptly.
Temperatures
. If distribution of
					 the final product to the public is being contemplated, then temperatures must
					 be taken and recorded daily (at least 5 days per week) until the
					 time/temperature standard has been met. (The procedures for taking temperatures
					 are given in the section on taking temperatures on page 10.) To be meaningful,
					 temperatures should be taken in the same locations each time. Marking the
					 locations for temperatures with a stake, flag or other marker helps make
					 temperature taking more consistent. Graphing pile temperatures is a good way to
					 visualize how the pile is performing over time and may help in making
					 management decisions in the future.
If carcasses are being added to the end of an existing
					 windrow and the time is more than 2 weeks between successive additions, there
					 should be a gap left and treat the continuation as a new windrow for the
					 purpose of taking temperatures and management activities.
Moisture
. Moisture can be checked
					 using a squeeze test. The compost medium should be damp to the touch when a
					 small amount is squeezed by hand but not so wet that water drips out
Record Keeping
Record keeping is important in composting as in all other
					 farm activities. Here are some records that should be maintained:
Location and Date piles built
. It
					 is important, especially if the compost is to be distributed to the public,
					 that each batch be identified uniquely. This unique identification should
					 include the pile location on the site and the start date. The date when the
					 last addition of raw ingredient is made is usually recorded as the start date.
					 It is from that date, that the time/temperature requirements are
					 tracked.
Temperatures
. (See sample
					 temperature chart in Appendix.) Temperature records must be maintained if the
					 compost product is to be distributed to the public. Even if the product is to
					 be used on the farm fields, the temperature records are a useful tool in
					 evaluating the compost process.
Disposition of Compost
. If the
					 farm operation is required to have a nutrient management plan under Maine law (
					 7 MRSA
					 §4201 - §
																4209 ), the farm must maintain a
					 record of the disposition of all nutrients, including compost, that were
					 generated on the farm or brought on to the farm. Even if a nutrient management
					 plan is not required, there should be a record of the final disposition of each
					 batch, whether it is distributed to the public or used on the farm's own
					 fields.
Emergency Disposal Situations
.
					 Chapter 211 requires that for emergency carcass disposal situations, the
					 following records shall be kept for
at least one year after the compost
					 product has been distributed
: Location and date piles built,
					 Temperatures measured in the compost piles, record of the disposition of the
					 compost.
Biosecurity
For Livestock operations, biosecurity has become an
					 important consideration. The threat of the spread of highly contagious diseases
					 is ever present. A compost operation on a farm should adhere to biosecurity
					 measures just as other farm operations do. (See the references for useful
					 publications on farm biosecurity measures.) Here are some biosecurity
					 considerations:
Good pile construction and
					 maintenance
. For routine mortality, one of the most important
					 biosecurity measures is taking care to build the compost pile correctly to
					 discourage disease vectors (scavengers) from disturbing the pile. Likewise,
					 prompt maintenance when cracks appear or part of a carcass is exposed is a
					 must. Take care not to use the same equipment for the raw inputs and finished
					 product unless it has been cleaned after handling raw materials.
Large scale disaster
. In cases of
					 where a large number of carcasses must be managed quickly, it may be necessary
					 to bring additional equipment, personnel or materials onto the farm to handle
					 the larger volume. Biosecurity protocols should be established to minimize the
					 amount of traffic on and off the farm, to ensure proper disinfection procedures
					 are used and to limit exposure of livestock to off-farm traffic.
Disease outbreak
. In the case of a
					 disease outbreak, the farm operation should contact their veterinarian as soon
					 as possible to assess the disease. If the veterinarian suspects that it is a
					 reportable disease, he or she will then notify the appropriate state and
					 federal animal health authorities for direction on implementing biosecurity
					 measures.
Small Backyard Poultry Flocks
Most of the systems or approaches described in this
					 document are intended for use by commercial agricultural operations. Small
					 flock owners should refer to University of Maine Cooperative Extension
					 bulletin: "Safe Disposal of Backyard Poultry Mortalities". (2006) for guidance
					 in disposing of a small number of birds in an emergency.
DIAGRAM 1
.
DIMENSIONS OF COMPOST WINDROWS FOR DAIRY
					 COWS.
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DIAGRAM 2
.
COMPOST WINDROW LAYOUT FOR LARGE ANIMAL
					 CARCASSES
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DIAGRAM 3
.
WINDROW CROSS SECTION FOR LARGE
					 CARCASSES
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DIAGRAM 4
WINDROW CONSTRUCTION for MEDIUM SIZE
					 CARCASSES
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DIAGRAM 5
WINDROW CONSTRUCTION for POULTRY AND OTHER SMALL
					 CARCASSES
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DIAGRAM 6
WINDROW CONSTRUCTION for OFFAL
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DIAGRAM 7.
LAYERING FOR A TURNED WINDROW PRIOR TO
					 TURNING
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DIAGRAM 8
LAYOUT FOR AN AERATED STATIC PILE
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DIAGRAM 9 .
LAYERING IN THE MARYLAND BIN COMPOST
					 SYSTEM
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Bibliography
Seekins, Bill. 2007. Best Management Practices for Large
					 Animal Carcass Composting. Maine Department of Agriculture, Food, and Rural
					 Resources.
King, M., B. Seekins, and M. Hutchinson. 2005. Observations
					 of Static Pile Composting of Large Animal Carcasses Using Different Media.
					 Unpublished report by the Maine Compost Team.
South NTC Bulletin No. 5210-0-05. South National Technical
					 Center. USDA. Soil Conservation Service. Fort Worth, Texas. February,
					 1990.
South NTC Bulletin No. 5210-0-10. South National Technical
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Maine Department of Environmental Protection. Maine Solid
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					 18, 2009.
Maine Department of Agriculture. Guidelines for Siting
					 Compost Operations. November 21, 2005 Cooperative Extension Service. Composting
					 Poultry Carcasses. MP 317. University of Arkansas.
Maryland Cooperative Extension Service. Maryland
					 Freestanding 2-Stage Composter; Isometric Poultry Composting Shed.
					 1988.1.
Brodie, H. and L. Carr. Composting Animal Mortalities on
					 the Farm. Fact Sheet 717. University of Maryland Cooperative Extension.
Rynk, R (Editor) 1992. On-Farm Composting Handbook.
					 NRAES-54. Northeast Regional Agricultural Engineering Service.
Dougherty, M (editor) 1999. Field Guide to On-Farm
					 Composting. NRAES-114. Natural Resource, Agriculture and Engineering
					 Service.
Natural Rendering: Composting Livestock Mortality and
					 Butcher Waste.
Cornell Waste Management Institute. Department of Crop
					 & Soil Sciences Rice Hall Ithaca, NY 14853
Carcass Disposal: A comprehensive Review. National
					 Agricultural Biosecurity Center, Kansas State University. 2004.
University of Maine Cooperative Extension. Safe Disposal of
					 Backyard Poultry Mortalities. 2006.
Maine Department of Agriculture, Food and Rural Resources.
					 2011. Chapter 211. Rules for the Disposal of Animal Carcasses.
Maryland Cooperative Extension. Fact Sheet 801: Guidelines
					 for In-house Composting of Catastrophic Poultry Mortality. 2002 Bowman, G. L.,
					 and W. P. Shulaw. 2001. Biosecurity Fundamentals for Extension Personnel.
					 Extension Fact Sheet VME. The Ohio State University.
Bowman, G. L., and W. P. Shulaw. 2001. Disinfection in
					 On-Farm Biosecurity Procedures. Extension Fact Sheet VME. The Ohio State
					 University.
Best Management Practices for the Prevention of Entry of
					 Disease onto Livestock Operations. 2001. New York State Cattle Health Assurance
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Ellis, R. 2001. Best Management Practices for Farm
					 Visitors. New York State Cattle Health Assurance Program Flory, Gary A.;
					 Bendfeldt, E.S.; Peer, R.W.; Zirkle, C.; Malone, G.W. 2006. Guidelines for
					 In-House Composting Poultry Mortality as a Rapid Response to Avian Influenza.
					 Virginia Department of Environmental Quality and University of Delaware.
Tablante, Nathaniel L.; Carr, L.E.; Malone, G.W.;
					 Patterson, P.H.; Hegngi, F.N.; Felton, G.; Zimmerman, N. Guidelines for
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					 Extension. Fact Sheet 801.
Hawkins, Ben; Fraser, H.; Groot-Nibbelink, B.; Joynes, K.;
					 Taylor, T.; Wand, C.; Bradshaw, S.; Fleming, C. Best Management Practices:
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Council for Agricultural Science and Technology (CAST).
					 2008. Poultry Carcass Disposal Options for Routine and Catastrophic Mortality.
					 Issue Paper 40. CAST, Ames, Iowa.
Seekins, William; Hutchinson, Mark; King, Mark; MacDonald,
					 George. 2011. Observations from Research Trials on Large Animal Composting
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					 here to view Image