Composting
Animal
Mortalities
Minnesota Department of Agriculture
Agricultural Development Division
in cooperation with
Minnesota Board of Animal Health
University of Minnesota Extension Service
Composting
Animal
Mortalities
Acknowledgments
Author
Debra Elias Morse
Project Team
Keith Friendshuh, Minnesota Board of Animal Health
Mary Hanks, MN Department of Agriculture
Robert Iwan, formerly, MN Department of Agriculture
David Schmidt, University of Minnesota Extension Service
Updated July 2006
If you would like additional copies of this report and/or
you have questions, please contact:
Agricultural Resources Management and Development Division
Minnesota Department of Agriculture
625 Robert Street North., St. Paul, MN 55155-2538
(651) 201-6673 • [email protected]
This report is also available on the Minnesota Department
of Agriculture web site: www.mda.state.mn.us
CONTENTS
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
The Mortality Composting Process . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
How Composting Works on the Farm . . . . . . . . . . . . . . . . . . . . . .6
Changes in Materials During Composting . . . . . . . . . . . . . . . . . .7
Why Composting is a Good Choice . . . . . . . . . . . . . . . . . . . . . . . .7
Commonly Asked Questions About Composting . . . . . . . . . . . . . . . .8
The Mechanics of Composting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
What You Need to Get Started
Bulking Agent. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Other Ingredients . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Other Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Composting Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Size of the Composting Structure . . . . . . . . . . . . . . . . . . . . . . . . . .16
Designing the Compost Structure . . . . . . . . . . . . . . . . . . . . . . . . .17
Factors in Site Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
How to Compost Step by Step
Building the Compost Pile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Monitoring the First Heat Cycle . . . . . . . . . . . . . . . . . . . . . . . . . .21
Turning the Pile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Monitoring the Second Heat Cycle . . . . . . . . . . . . . . . . . . . . . . . .22
Finishing the Composting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Notes on Winter Composting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Notes on Emergency Composting . . . . . . . . . . . . . . . . . . . . . . . . .23
Monitoring and Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Use of Compost on the Farm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Regulations
Minnesota Board of Animal Health Rules . . . . . . . . . . . . . . . . . .25
Local Rules and Regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Minnesota State Agencies and Other Key Organizations . . . . . . . . . .27
Further Resources
Publications and Web Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Thermometer Suppliers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Composting Animal Mortalities
7
INTRODUCTION
The management of animal mortalities is an important aspect of
livestock farming since even the best livestock farmers lose some of
their animals each year. Rendering, burial, and incineration have
been the typical carcass disposal methods. However, these options
are becoming less practical for many farmers because of decreasing
availability and higher costs of rendering, biosecurity concerns, and
potential adverse effects on groundwater and air quality. For these
reasons, composting is becoming more widely used as a method of
mortality disposal. A properly managed mortality composting system
is low cost, environmentally sound, biosecure, and virtually odor free.
While there is much in favor of composting, you must decide
whether or not it fits into your operation. Minnesota Board of
Animal Health regulations allow composting of poultry, swine,
sheep, and goats without a permit, and cattle can legally be
composted if a permit is obtained. Like any other farm operation,
successful composting requires a commitment to managing it well.
This publication describes mortality composting, answers commonly
asked questions, outlines what is needed to compost on your farm,
explains how to compost step-by-step, and outlines applicable
regulations. It also contains resources for more information.
THE MORTALITY COMPOSTING
PROCESS
Composting is a naturally occurring process in which bacteria,
fungi, and other microorganisms convert organic material into a
stabilized product termed compost. This means that microorganisms
do the composting work for you. Your role in managing the
composting process is to make sure that the microorganisms have
the environment they need in order to do their work quickly and
effectively.
In mortality composting, the animal carcass is placed in a composting
bin. A bulking agent such as sawdust or straw that is high in carbon
is placed around the carcass to completely surround it.
Composting is an aerobic,
natural process in which
microorganisms convert or-
ganic material into a stable
product called compost.
Minnesota Department of Agriculture
8
Within the carcass, anaerobic microorganisms work to degrade it, re-
leasing fluids and odorous gases such as hydrogen sulfide and ammo-
nia. These diffuse into the surrounding bulking agent. In this bulking
agent, aerobic microorganisms degrade these materials to odor-free
carbon dioxide (CO
2
) and water (H
2
O). The aerobic process produc-
es considerable heat, causing the temperature of the compost pile to
rise. The active bacteria in both the aerobic and anaerobic zones are
heat tolerant. However, the heat kills common viruses and bacteria
that may be present in the carcass. Odor is controlled by having an
adequate quantity of bulking agent around the carcass.
The compost pile is usually left undisturbed until the temperature
has subsided, meaning that the aerobic microorganisms are work-
ing less efficiently because they have exhausted much of the food
and air in their environment. At this point the flesh and small bones
will have decomposed. After this first heat cycle, the pile is turned,
introducing air into the pile. This increases aerobic activity and the
temperature rises again. After the temperature subsides a second
time, the compost should be finished, with no flesh, hide, or small
bones present, although some large bones may remain.
How the Mortality Composting Process
Works on the Farm
On the farm, at least three composting bins are used:
1. A primary bin in the process of being filled
2. Another primary bin in the first heat cycle of composting, and
3. A secondary bin in the second heat cycle
When you first start composting, new carcasses and bulking agent
are added to the first bin until the bin is full. This pile is then left
to compost and new carcasses are layered with bulking agent into a
second bin. When the first pile has completed the first heat cycle, the
pile is turned by moving it to a third empty bin, and it is left to com-
post for the second heat cycle. By this time, the second bin is usually
full and is left to compost. A new pile is started in the first bin, which
is now empty. When the first pile has gone through the second heat
cycle, it is removed from the bin and either stored or spread on crop
fields. This on-going process ensures that carcasses can be disposed
of continuously.
It takes from 7 to 24 weeks for carcasses to degrade and for the
compost to reach the finished stage. The amount of time required
depends on the bulking agent used, temperature, moisture, manage-
ment, and the size of the animal (large animals can take longer to
decompose than small animals).
Composting produces
• Carbon dioxide
• Water
• Heat
• Fertilizer
Composting Animal Mortalities
9
The Animal Mortality Composting Process
First Heat Cycle
• Carcasses and bulking agent layered in pile
• High rate of anaerobic and aerobic activity
• Temperature increases
• Breakdown of flesh and small bones
• Temperature subsides
Second Heat Cycle
• Turning the pile initiates increased aerobic activity
• Temperature increases
• Breakdown of long bones, skull and pelvis
• Stabilization of compost material
• Temperature subsides
Changes in Materials During Composting
By the time composting is complete, the material becomes more
uniform and less active biologically. The material (humus) becomes
dark brown to black in color. The particles reduce in size and
become consistent and soil-like in texture. The volume and weight of
materials are reduced due to loss of carbon dioxide and water to the
atmosphere and to bulky raw materials changing into crumbly, fine-
textured compost.
Why Composting is a Good Choice
Biosecure
Composting allows immediate year-round disposal of carcasses so
that disease is not spread. There is no entry of off-farm vehicles that
can bring disease onto the farm from other operations, and the high
temperatures in the compost pile kill pathogens.
Environmentally sound
A properly functioning compost pile gives off little odor and does
not harm or affect groundwater. Composting turns a waste into a
beneficial fertilizer and soil amendment, resulting in on-farm nutri-
ent recycling.
Cost effective
Composting has low to moderate start up costs and minimal
operating costs.
Easy to accomplish
Composting requires only good management and minimal training.
Finished compost is
• Consistent and soil-like
• Dark brown to black
• Reduced in volume
and weight
Composting is
• Biosecure
• Environmentally sound
• Cost effective
• Easy
Minnesota Department of Agriculture
10
COMMONLY ASKED QUESTIONS
About Composting
Will I have problems with odor?
No. A properly managed compost pile with enough bulking agent
will not produce offensive odors. Farmer cooperators in three
Minnesota demonstration projects found that the layer of sawdust
or bedding on top of the pile greatly reduced odor and, once the
compost heated up, offensive odors were essentially absent.
Will the composting piles attract flies and rodents?
No. Flies are not a problem because internal temperatures above
130
o
F will kill existing fly larvae. Also, when piles are covered by at
least 12 inches of bulking agent, flies and rodents are not attracted
to the area. If manure is used in the pile and not covered adequately
by a bulking agent, some flies may be present on the surface but they
will not be able to reproduce.
Will the compost spread diseases?
No. The high temperatures of proper composting will destroy most
harmful bacteria and viruses associated with livestock. Viruses that
cause avian influenza, Newcastle disease and pseudorabies are com-
pletely inactivated by the end of the second heat cycle. Bacteria such
as Salmonella enteritidis, Pasteurella multocida, Erysipelas rhusiopathiae
and Salmonella cholerasuis will be successfully destroyed by the com-
posting process.
Will composting work with all animals?
Yes. Poultry, swine, sheep, and goats can all be composted without a
permit. The Minnesota Board of Animal Health regulations require
a permit for cattle. With larger animals such as sows and larger
cattle, some of their large bones may take longer to decompose than
with smaller animals. These bones can be removed from the finished
compost and returned to an active pile for further composting.
Note that while any species can be composted, Minnesota Board of
Animal Health regulations do not allow composting of any animals
that died from anthrax or toxic materials.
Will I recognize animal parts in the compost when I turn it?
No. Farmer cooperators in three Minnesota demonstration projects
found that when the piles were ready for the first turning, the only
recognizable parts were larger bones, teeth, and pieces of hides.
These bones were rubbery and decalcified, and could be broken eas-
ily. There were even fewer after the second turning.
Composting Animal Mortalities
11
Is composting costly?
No.
The main cost is in building a composting structure. Some
farmers in Minnesota have renovated existing buildings for little
cost. Another cost may be a front-end or skid steer loader to handle
the mortalities and compost. The only on-going cost is the bulking
agent and the skid steer. Your farm may have bulking agents (such as
straw, litter, bedding, or corn stalks) available at no cost. If not, you
will have to purchase bulking agent. This cost should be minimal.
Will composting take a lot of labor?
No.
The labor involved is minimal, consisting of placing any new
mortalities in the bin every day and covering them with bulking
agent, checking the temperature of the pile every day, moving the
pile between the primary and secondary stages of composting, and
moving the finished compost to storage. One Minnesota farmer who
had a composting demonstration site on his farm estimated that it
took about ten minutes each day to manage.
Are there uses for the compost when it’s done?
Yes.
The finished compost can be used in your next compost pile
to replace part of the bulking agent and provide a large microbial
population right away. It can also be spread on crop fields to provide
beneficial organic matter and nutrients to the soil and the crops.
Can composting be done in the winter in Minnesota?
Yes.
Active piles will continue to heat during the winter. New piles
should not be started during the winter unless active, hot compost is
available as the bulking agent.
Can any size operation use composting?
Yes.
However, if small operations use a seasonal livestock
production cycle, they may have trouble composting in winter if the
input of carcasses is small and inconsistent. Small compost piles do
not heat as fast or as hot and are not self-insulated, and therefore
may not reach ideal temperatures in winter.
Can varmits be a problem around the compost pile?
Yes. Visiting dogs, coyotes, raccoon, skunk and fox can become
problems. A very hot and active compost pile where the carcasses
are adequately covered is the best solution.
Minnesota Department of Agriculture
12
THE MECHANICS of Composting
Your job in managing the compost pile is to provide the right food
and environment for the microorganisms so that they can get their
composting work done quickly and effectively. There are four as-
pects of the compost pile that are important to microorganisms and
that are important in your management of the process.
1. Carbon: Because animal carcasses are very high in nitrogen, you
must add large amounts of carbon (in the form of a bulking agent)
to the pile in order to provide the right environment and food for
the composting microorganisms. The carbon to nitrogen ratio (C:
N ratio) describes the amount of carbon compared to the amount
of nitrogen in the pile. Minnesota Board of Animal Health regula-
tions require that the C:N ratio of the pile be between 15:1 and 35:1.
However, you don’t need to be too worried about measuring the
exact C:N ratio, since the composting process is fairly forgiving and
will occur under a range of C:N ratios, as long as you keep the over-
all carbon to nitrogen balance in mind. If there is too little carbon
(low C:N), the high nitrogen supply is converted to ammonia and is
emitted from the pile, resulting in odors. If there is too much car-
bon (high C:N), the low nitrogen supply can limit microbial activity
resulting in slow carcass decomposition and cool temperatures.
2. Air Flow: Since aerobic microorganisms need oxygen to work,
oxygen must be able to move into the pile and carbon dioxide and
water vapor must be able to escape. This means that the bulking
agent must have a particle size that allows air to move freely. Bulk-
ing agents, such as newsprint, can pack down, inhibiting air flow to
the microorganisms, which will slow or even stop the composting
process and produce odors. Large particles, such as branches, can let
too much air in, cooling the pile and slowing down the work of the
microorganisms.
3. Moisture Content: Microorganisms require water as a medium
for chemical reactions, to transport nutrients, and to move about.
Compost with too little moisture will not supply sufficient water for
microorganisms to survive. Too much moisture inhibits oxygen flow
through the pile, causing aerobic microorganisms to slow down,
which can lead to odors.
4. Temperature: Temperature is both a necessity for and a result
of microorganisms’ work. The warmer the pile, the faster the
micro-organisms work, the more heat they produce, the warmer
the pile, and so on. If the temperature is too low (less than 120
o
F),
microorganisms are not very active, which means decomposition will
occur at a slow rate and pathogens and weed seeds will not be
Compost
microorganisms
need
• Carbon
• Air
• Water
• Elevated temperature
Composting Animal Mortalities
13
destroyed. The temperature should reach 130
o
to 150
o
F for several
days or weeks because at this temperature, microorganisms are ac-
tive, decomposition proceeds quickly, and pathogens are destroyed.
WHAT YOU NEED TO GET STARTED
Bulking Agent
Many organic materials can be used as bulking agents, but different
materials vary in their availability, cost, and physical characteristics.
Sawdust has been widely used and has excellent odor-absorbing
potential. Hay and straw will also work. Greener hay or hay with
more legumes will have less carbon (lower C:N ratio) while drier hay
or hay with more grass will have more carbon
(higher C:N ratio). Crop residues such as
wheat straw or corn stalks can be used but may
require shredding or some form of particle size
reduction.
You can also use finished compost as part of
the bulking agent in a new pile. This has the
advantage of inoculating the new pile with mi-
croorganisms. Some typical bulking agents and
their characteristics are shown here.
When choosing a bulking agent, you
should also consider:
1. Availability: You must have access all year to
enough bulking agent to make sure your piles
compost well. Check out both on-farm and off-
farm sources and make sure the bulking agent
you decide to use will be available consistently
and in high enough quantities from one or
more sources throughout the year.
2. Cost: While the cost of on-farm materials is
low, it is possible to find bulking agents from
other sources that may also be low cost. This
is especially true for materials that are consid-
ered waste products such as sawdust or wood shavings.
Bulking agent considerations
• Availability
• Cost
• Particle surface area
• Carbon to nitrogen ratio
Common Composting
Materials
Carbon to
Substance Nitrogen Ratio
(Weight to Weight)
Sawdust
1
200 - 750 :1
Straw
1
48 - 150 :1
Corn stalks
1
60 - 73 :1
Finished compost
1
30 - 50 :1
Horse manure
1
22 - 50 :1
Turkey litter
1
16 :1
Animal carcass
2
5 :1
Swine manure
2
1 - 3 :1
1
On-Farm Composting Handbook, NRAES-54, Natural
Resource, Agriculture, and Engineering Service, Ithaca,
New York.
2
Compost Materials, 1996, EBAE172-93, North Carolina
Cooperative Extension Service, Raleigh, North Carolina
Minnesota Department of Agriculture
14
3. Physical Characteristics: The physical characteristics of the
bulking agent will affect how well your compost piles work. In
addition to choosing a bulking agent with the appropriate C:N ratio,
you want to find a bulking agent with a large enough particle size to
let air flow, but not to the point that it cools the pile. It should have
enough surface area for the microorganisms to grab onto.
Whatever bulking agent you decide to use, you can calculate the
annual volume needed based on your annual death loss. Using
sawdust as an example to estimate the bulking agent volume you
will need for one year of composting, first determine the pounds of
death loss you have per year (use tables on pages 16 and 17), and
then multiply by .0067 yd
3
per pound of dead animal. This will give
you an estimate for planning purposes only. Other bulking agents
may differ. If you will use finished compost to replace part of your
bulking agent, remember to factor that into your estimates.
Water
Composting happens most ideally when the pile is moist. This means
that you may have to add water to your compost pile. The amount
of water you will add will depend on the moisture content of your
compost ingredients, especially of your bulking agent. In general,
you can judge the proper moisture content by feeling the compost.
It should be moist and leave your hand feeling moist, but you should
not be able to squeeze any water out of it.
Other Ingredients
Manure can also be used in the compost pile but is not necessary.
Manure tends to be high in nitrogen and low in carbon . The advan-
tages of using manure are that it adds microorganisms to the pile,
adds nitrogen which can help speed up the composting process, and
adds moisture. The disadvantage is the danger of excessive nitrogen
in the pile resulting in odor, flies and other composting problems.
You may have to add more bulking agent to compensate for the
increased nitrogen.
Composting Animal Mortalities
15
Liquid manure has very little carbon (low C:N ratio), while manures
cleaned from stalls may include bedding material which will increase
the carbon (higher C:N ratio). Turkey litter has been used in some
composting piles in Minnesota.
Other Supplies
Thermometer: A probe-type thermometer with a minimum 36-inch
stainless steel stem is needed to monitor the pile. Suppliers of ther-
mometers are included in Further Resources.
Composting Log: A logbook is needed where you can record dates
and weights of carcasses placed in the composter, temperature read-
ings, amounts of bulking agent used, dates when compost is turned,
and dates and amounts of finished compost.
Front-End or Skid Steer Loader: The loader is needed to move
carcasses from the production buildings to the composter, place
carcasses in the compost pile, cover the carcasses with bulking agent,
mix and turn compost, and move finished compost.
Manure Spreader: A manure spreader should be available for field
spreading finished compost.
Hoop structure with six bins;
note concrete apron and
sawdust pile in foreground.
Minnesota Department of Agriculture
16
COMPOSTING STRUCTURES
A wide range of structures is possible, including new or existing
facilities, and stand-alone units or add-ons to an existing building.
For new facilities, poured concrete, pole construction, and hoop
houses have all been used in Minnesota. Existing facilities, such as
machine sheds, corn cribs, or cattle sheds can be adapted if the ceil-
ing is high enough to allow the front-end or skid loader to lift and
turn the compost. This can be a low cost option. One Minnesota
farmer adapted a Cargill open-front unit for composting with no
remodeling costs.
Minnesota State Board of Animal Health regulations recommend
that the structure be:
• built on an impervious weight-bearing pad that is large enough to
allow the equipment to maneuver. A concrete pad or other surface
prevents seepage of nutrients and bacteria to groundwater. An
8-foot apron to at least support the front wheels of the loader is the
minimum recommended; concrete to support the entire tractor
is recommended.
• covered with a roof or other water-repel-
ling materials to prevent excessive moisture
on the composting material. A roof excludes
rainwater and snow from the compost piles.
The roof overhang should minimize rain
blowing into the bins.
• built of rot resistant material that is strong
enough to withstand the force exerted by the
equipment. Possible construction materials
for the bins include preservative pressure-
treated lumber and concrete. To avoid cor-
rosion, ventilation is needed and hot-dipped
galvanized nails should be used.
Bins should be located close to each other to facilitate moving com-
post from bin to bin. Consider snow and wind loads in the design. If
you find you have problems with dogs or other animals that dig in the
piles, you might want to add a removable gate. Opposite are some
photos of typical composting structures used in Minnesota.
Composting structure
regulations
• Impervious weight
bearing pad
• Covered
• Rot resistant building
materials
Multiple bin composting structure; note gates on
fronts of bins.
Composting Animal Mortalities
17
Hoop structure for composting
with three bins.
A Cargill unit converted
for composting.
New three bin composting
structure.
Minnesota Department of Agriculture
18
Size of the Composting Structure
The size of your composting structure will depend on the size and
amount of dead animals to be composted on a daily basis. The adja-
cent table lists average death losses for different animals. The pri-
mary bin volume averages three to 20 cubic feet for every
pound of death loss. The table on the next page gives the
ratio by size of animal. Secondary bins (those used to turn
piles into for the second heat cycle) should be the same
number and volume as the primary bins. The three steps
described on the next page in the text box will help you
calculate the size and number of your composting bins.
Composting structures that are too small may force
movement of material through the bins before the com-
posting process is complete. This can increase manage-
ment problems.
Bin Size
Your goal in determining the bin size is to maximize the
effi ciency of the composting process and make it easy
to manage the mortalities and the composting materials.
All bins should be equally sized. Bin size depends on
the size of equipment you will be using to turn the com-
post and the type of animal you will be composting. Bin
width should be at least twice the width of the bucket on
the equipment you will be using. The size of the struc-
ture you might be renovating must also be considered
when determining bin size. Experts recommend that the
bin area (width x length) should be 100 to 400 square
feet to ensure proper heating and for ease of fi lling and
emptying over a short period of time.
Number of Bins
The number of bins will depend on the bin size and
your total composting volume of carcasses and bulk-
ing agent. The minimum number of bins is three, two
for composting and one being fi lled. Larger operations may require
more than three. Your goal in determining the number of bins is to
be able to successfully compost all of your animal mortalities. Min-
nesota State Board of Animal Health regulations require that the
composting structure be large enough to handle each day’s normal
mortality through a minimum of two heat cycles to the endpoint of
the composting. You will also need to consider where you will store
the bulking agent and fi nished compost. Having extra bins available
for this can be helpful.
Mortality Estimates
Average
Species Weight (lbs)
Loss (%)
Swine
1
wean to nursery 10
10-12
nursery 30 2-4
grow finish 150 2-4
sows 300 2-5
Poultry
2
broiler 3 5
layer 3 10
turkey hens 10 7
turkey toms 17 13
Beef
3
pre-wean 90 8-10
young stock 600 2-3
yearlings 850 1
cows 1250 1
Dairy
4
pre-wean 90 8-10
heifers 600 2-3
cows 1400 1
Goats and Sheep
pre-wean 8 8-10
lambs 50
10-12
mature 170 6-8
Composting Animal Mortalities
19
Designing the Compost Structure
Step One: Estimate the Weight of Average Daily Death
Loss.
You can use your own farm records or estimate the loss using
industry average loss rate. See the table on preceding page for
industry averages. Take the total pounds of dead animals for
the year and divide by 365 days per year. This is the pounds of
dead animals that need to be composted each day.
Step Two: Estimate the Volume for the Composting Bins.
Multiply the pounds of dead animals per day from Step One by
the cubic feet per pound listed in the adjacent table for the av-
erage size of the animals to be composted. This is the required
volume for the primary composting area. Add an equal volume
for the secondary composting bins.
Example: You average 100 lb/day of death
loss. Average size of dead animal to be
composted is about 400 lb. The adjacent ta-
ble lists the bin volume of 14 ft
3
/lb of death
loss for animals of that size. (100 lb/ day
death loss) x (14 ft
3
/lb) = 1400 cubic feet of
primary bin space and an equal amount of
secondary bin space.
Step Three: Design the Bins.
Start with the bucket width on the loader
you will be using. Multiply that width by 2
and round the number up a couple of feet
to allow some maneuvering room. For example, if the bucket
is 4 ft. wide, you might start your bin design with a width of 10
ft. Depth of the pile should be between five to eight feet. Bins
should be at least eight feet long to obtain good pile heating.
Try various bin dimensions and number of bins so that the
volume available equals the volume calculated above. Bin area
(width x length) should fall between 100 and 400 square feet.
Include the same number of secondary bins of the same volume
and consider adding additional bins for bulking agent storage.
Example:
(10 ft. wide to accommodate loader bucket) x (14 ft.
long) x (5 ft. deep) = 700 ft
3
per bin. As calculated above, 1400
cubic feet of primary bin space is required to compost daily death
loss. 1400 ft
3
divided by 700 ft
3
per bin = 2 primary bins needed.
Add two secondary bins of the same size and one bin for bulking
agent storage gives a total of 5 bins measuring 10’ x 14’ x 5’.
Multiplier Factor to Estimate
Bin Volume by Animal Size
Multiply
Carcass Size (lb) Death Loss by
0-10 3 ft
3
/lb
10-25 5 ft
3
/lb
25-300 10 ft
3
/lb
300-750 14 ft
3
/lb
750-1400 20 ft
3
/lb
Minnesota Department of Agriculture
20
Factors in Site Selection
of the Composting Structure
Besides the following factors, Minnesota State Board of Animal
Health regulations require that Minnesota Pollution Control Agency
and local rules also be followed in siting your structure.
Water quality
Avoid wet areas or flood plains. The facility must be high and dry.
Locate at least three feet above high water table and at least 300 feet
from streams, ponds, or lakes in the same drainage area. Divert clean
water and provide for runoff collection and treatment or storage
areas.
Biosecurity
Avoid locating the compost structure directly next to production
units and use appropriate cleaning procedures on transportation
vehicles.
Public perception
Minnesota State Board of Animal Health regulations require that
consideration be given to prevailing winds and public view in choos-
ing a site. Provide limited or appealing view for neighbors or pass-
ing motorists and consider aesthetics and landscaping.
Traffic flow
Consider access and traffic patterns required for moving mortali-
ties and bulking agent to the composter and removing finished
compost, as well as other farm traffic. Minnesota Board of Animal
Health regulations require that carcasses be transported over public
roads only in vehicles or containers that are leakproof and covered.
Ensure all weather access. Locate safe distances from buried and
overhead utilities.
Availability of water
Consider the distance between a water source and the bulking agent
storage or the composting bins. If you need to add moisture to your
composting materials, either to the bulking agent or to the piles, con-
sider locating the structure within one hose length of a water source.
Site selection
considerations
• Water quality
• Biosecurity
• Public view
• Traffic flow
• Water source
Composting Animal Mortalities
21
HOW TO COMPOST STEP BY STEP
Building the Compost Pile
Before you start composting, review the Board of Animal Health
Regulations found at the end of this publication.
• Place at least 12 inches of bulking agent on the floor of the com-
posting bin. This layer will insulate the composting material from the
outside environment, provide carbon to fuel the composting process,
and absorb liquids.
• Place the carcasses in a single layer on top of the bulking agent one
foot from the wall of the bin and at least six inches apart. This allows
air to circulate around the carcasses and insulates them from the en-
vironment. Depending on the size of the bin and of your loader, you
may not want to build a whole single layer first, because your loader
may not be able to reach the back of the bin when you want to add
more carcasses later. You can avoid this by building the pile from the
back, building it up and forward simultaneously.
• Cover the carcasses with about 12 inches of bulking agent. Add
water as needed to maintain the proper moisture level. Because it is
difficult to add water evenly, you might want to consider adding it to
the bulking agent before it goes on the pile. Caution: If the pile dries
out (25% to 45% moisture) and if piles are too large, spontaneous
combustion can occur, just as with hay or silage. Attention to mois-
ture, temperature, and pile size is the best protection. An accessible
water supply is a good safety precaution. If you are going to use
manure, add it either beneath the bulking agent or incorporated with
the bulking agent. The pile is now ready for the next layer.
Building the compost pile
• Bulking agent base
• Layer carcasses
• Cover with bulking agent
• Record information
in log book
Minnesota Department of Agriculture
22
Transporting dead sow to
composting structure.
One thousand pounds of
pigs added in two layers.
• Record the species, class, and weight of the carcasses, and the
amount and type of bulking agent and into the compost log.
• Place additional carcasses as they become available on the pile in
layers following these same steps, allowing 6 to 12 inches of bulking
agent between layers. Minnesota Board of Animal Health regula-
tions require that animal mortality be processed daily. You can com-
post more than one species in the same bin. It may be necessary to
use the loader bucket to dig a depression to hold the fresh carcass in
place before covering it with bulking agent, especially if it is a large
animal. Continue adding carcasses until the pile is close to the top of
the bin. Cover the top of the pile with 12 inches of bulking agent to
reduce odor and protect against pests. Minnesota Board of Animal
Health regulations require that flies, rodents, and vermin be con-
trolled so as not to be a health hazard to human or animal popula-
tions.
• After the bin is full, start a second bin following these same steps.
Leave the first bin to compost. This first bin has carcasses at various
stages of decomposition from largely decomposed (first one in) to
just beginning (last one in).
Composting Animal Mortalities
23
Dead sow placed in depression
formed in bulking agent.
Covering with bulking agent;
note that skid loader fits
into bin.
Monitoring the First Heat Cycle
• Monitor the pile daily to make sure that all carcass parts stay com-
pletely covered by bulking agent. The pile will settle, so you may need to
add additional bulking agent over the top.
• Check the temperature daily and record it in the compost log. The
temperature should be taken at multiple locations in the pile, especially
near the last animal that was added. Temperatures should be increasing
and should soon be between 130
o
and 150
o
F.
• If it seems that the pile is not composting correctly
because of the temperature or because there are odors,
you will need to do some troubleshooting and make
adjustments. See the section on troubleshooting for
more information.
• Once the pile reaches at least 130
o
F, it should stay
above that temperature for at least one week. Do not
start counting the days until the area that you added to
the pile last reaches this temperature. When the tem-
perature drops, the pile is ready to be turned.
• The typical primary composting time is approximate-
ly 45 days for carcasses weighing from 25 to 300 lbs. See the table of
estimates for primary composting times by carcass weight.
Monitoring
• Record temperature daily
• Check odor and moisture
• Troubleshoot and adjust
Primary Composting Times
Estimated
Primary
Carcass Size (lb) Composting Days
0-10 15
10-25 22
25-300 45
300-750 60
Minnesota Department of Agriculture
24
Turning the Pile
• Layer the bottom of an empty bin with 12 inches of bulking agent.
• Use a front-end or skid loader to move the
material from the primary bin to the second-
ary bin, one bucket at a time. This aerates
the pile. Minimal flesh or soft bones should
be present, but long bones, skulls, teeth, and
pelvis, and some hide, feathers, and fleece
may remain. There may be some odor while
turning due to disturbance of the anaerobic
zones. Look to see whether you need to add
water. If you do, add it to the existing pile as
needed before or while you turn it, so that it
gets evenly incorporated.
Caution: High temperatures created by the composting material could
lead to burns of the skin if caution is not exercised during compost han-
dling.
• Cover the fresh pile with another 12 inches of bulking agent to
prevent odor and visits by scavenging animals.
• Record the date turned and bulking agent type and volume used in
the compost log.
Appearance of carcasses after
first heat cycle.
Monitoring the Second Heat Cycle
• Monitor and record the temperature of the turned pile daily. Since
the composting materials are more consistent now, you don’t need
to be as careful about taking the temperature in multiple locations.
• Once the pile maintains a temperature in excess of 130
o
F for
seven days and then drops, the compost may be finished.
• Secondary composting times will be similar to the number of days
in the primary cycle.
Compost Bin Management
Example for a 3-bin, 2-turn system with 15 days in
primary heat cycle.
Days Primary Bin 1 Primary Bin 2 Secondary Bin
1-15 filling empty empty
16-30 1st heat filling empty
31-45 filling 1st heat 2nd heat (#1)
46-60 1st heat filling 2nd heat (#2)
61-85 filling 1st heat 2nd heat (#1)
Composting Animal Mortalities
25
Finishing the Composting
Inspect the pile. If you can no longer see any flesh, the compost can
be termed “finished.” It should be dark, humus-like material with very
little odor. At this stage, any bones should be so brittle that they can
be easily crushed. Minnesota Board of Animal Health regulations re-
quire that the finished product contain no visible pieces of soft tissue.
If there is still some flesh visible, you need to turn the pile again and
let it go through another heat cycle. With larger animals such as cattle
and sheep, more time is needed to completely compost their larger
and denser bones. If the compost is finished other than the bones,
remove them and place in a new pile for further decomposition.
Notes on Winter Composting
In order to compost in the winter, the compost pile must never be al-
lowed to go cold. New carcasses should not be allowed to freeze and
should not be added to a pile that has dropped below 60
o
F, which
is too cool for microbial activity to start. The compost pile must be
large enough to provide self-insulation. A thick layer of bulking
agent between the carcasses and the floor and walls of the bins will
insulate the microbial activity from cold air. Turning on extremely
cold days should be avoided. You can also do your composting in or
next to a heated area in the winter.
Notes on Catastrophic Herd/Flock Loss
Composting assistance is available if you suffer catastrophic animal
mortalities. Your capacity to effectively and safely compost your
carcasses may be rapidly exceeded with large losses. In the event
of a large scale loss due to disease, it is critical that you contact the
Minnesota Board of Animal Health for disease and emergency com-
posting guidance. In order to minimize spread of disease, poultry af-
fected with diseases, such as avian influenza can be composted inside
poultry barns.
Finished compost.
Information needed for
composting assistance
includes:
• Current on-site compost-
ing capacity
• Potential on-site compost-
ing capacity
• Availability of Compost-
ing supplies (e.g., wood
chips, sawdust or other
materials)
Emergency Contacts:
MN State Duty Officer
651-649-5451
Board of Animal Health
651-296-2942
Minnesota Department of Agriculture
26
MONITORING AND TROUBLESHOOTING
USE OF COMPOST ON THE FARM
Once the compost is finished, it may be used for some of the bulking
agent in a new composting pile. A rule of thumb is 50 percent, but
you may want to use more or less depending on how degraded the
bulking agent is in the finished compost. Using finished compost in
new compost piles reduces the amount of bulking agent you need in
the new pile and provides microbial inoculant.
Compost may also be applied to your fields. This should be consid-
ered part of your current manure management plan.
Troubleshooting Guide for Carcass Composting
Adapted from the National Pork Producers Council Swine Mortality Composting Module
Problem/
Symptom
Probable Cause Suggestions
Improper
Temperature
• Too dry
• Too wet
• Improper C:N ratio or bulk-
ing agent used is too porus
• Adverse environment
• Add water
• Add bulking agent and turn pile.
• Evaluate bulking agent and
adjust amount as necessary.
• Ensure adequate cover with
bulking agent to provide insula-
tion.
Failure to
Decompose
• Improper C:N ratio
• Carcasses layered too
thickly
• Carcasses placed on the
outside edge of the pile
• Turn pile and adjust amoun of
bulking agent.
• Single layer the carcasses
• Maintain one foot of space
between carcasses and outside
edge of bins..
Odor
• Too wet
• Too low C:N ratio
• Air flow restricted
• Inadequate cover over
carcasses
• Extended periods of low
temperature
• Add bulking agent and turn pile.
• Evaluate type of bulking agent
used. Add bulking agent.
• Maintain one foot of bulking
agentnear outside of bin. Turn
pile.
• Cover carcasses with one foot of
bulking agent.
• Follow steps in temperature
section.
Flies
• Inadequate cover over
carcasses
• Poor sanitation conditions
• Failure to achieve proper
temperature
• Too wet
• Cover carcasses with one foot
bulking agent.
• Avoid leaching from pile. Main-
tain a clean, debris free area near
the pile.
• Follow steps in temperature
section.
• Open/remove pile contents and
add additional bulking agent
Scavenging
Animals
• Inadequate cover over
carcasses
• Maintain one foot of cover.
carcasses
• Avoid initial entry by establishing
a fence or barrier.
Composting Animal Mortalities
27
Since there are no state rules or regulations that specifically address
land application of mortality compost, you should use the application
requirements for manure as guidelines. Compost nutrient estimates
are 15 lb of N, 5 lb of P
2
O
5
and 10 lb of K
2
O per ton of compost.
Nutrients would be higher if manure or turkey litter were used in the
compost. In order to determine the proper application rates for your
compost, you will need to determine its nutrient content and avail-
ability. Most soil and manure testing labs will do this.
REGULATIONS
Minnesota Board of Animal Health Rules
Composting structure
• built on an impervious weight-bearing pad that is large
enough to allow the equipment to maneuver. An 8-foot
apron to support the front wheels of the loader is the mini-
mum recommended though concrete to support the entire
loader is recommended.
• covered with a roof or other water-repelling materials to pre-
vent excessive moisture on the composting material. The roof
overhang should minimize rain blowing into the bins.
• built of rot resistant material that is strong enough to with-
stand the force exerted by the equipment. Possible
construction materials for the bins include preservative
pressuretreated lumber and concrete. To avoid corrosion,
ventilation is needed and hot-dipped galvanized nails should
be used.
• large enough to handle each day’s normal mortality through a
minimum of two heat cycles to the endpoint of composting.
• sited with consideration to prevailing winds and public view.
Compost Pile
• C:N ratio between 15:1 and 35:1.
• 12” base of bulking material.
• carcasses six inches from edges.
• reach a minimum of 130
o
F.
• carcasses covered and sealed with litter as they are
added to pile.
• flies, rodents, and vermin controlled so as not to be a
health hazard to human or animal populations.
• temperature taken and recorded daily.
• minimum of two heat cycles.
Livestock
• permit required for composting cattle.
• no composting of any animals that died from anthrax or
toxic materials.
Minnesota Department of Agriculture
28
• animal mortality processed daily.
• carcasses transported over public roads only in vehicles or
containers that are leak proof and covered.
Finished Compost
• minimum of two heat cycles have reached 130oF.
• finished product must not contain visible pieces of soft tissue.
• finished product must be handled and stored according to
Minnesota Pollution Control Agency and Department of
Agriculture regulations.
Protocol
The owner of the compost facility should have a written
protocol for the operation containing at least the minimum
steps outlined above in the composting process and should
instruct and be responsible for all employees to follow the
protocol.
Inspection
Representatives of the Board may inspect a composting facility
and may review the operation protocol at any reasonable time.
Penalties
Construction or operation of a compost facility in violation of
the rules results in penalties pertaining to improper disposal of
dead animals as well as possible charges for violations of the
rules of other state or local agencies.
Local Rules and Regulations
In addition to state regulations, most counties will require a
building permit to construct or modify an existing building for
composting. Before construction, contact your local zoning
office to obtain the necessary permits. Local governments may
have ordinances that are stricter than state regulations, or they
may not have ordinances that cover animal mortality compost-
ing. In this case, local feedlot rules governing animal waste are
generally used as guidelines for building the composting struc-
ture. Special or conditional use permits may be needed on a
local level for composting. County feedlot ordinances may have
carcass disposal requirements as part of the feedlot permit.
Composting Animal Mortalities
29
MINNESOTA STATE AGENCIES AND
OTHER KEY ORGANIZATIONS
Animal Mortality Composting Demonstration Sites.
For farmer demonstration sites, contact the Minnesota Department
of Agriculture, Agricultural Development Division, 90 W. Plato
Blvd., St. Paul, MN 55107. (651)296-7673.
Board of Animal Health (BAH).
625 Robert Street North, St. Paul, MN 55155-2538.
(651)296-2942. BAH Communications Staff: (651)201-6827
www.bah.state.mn.us/
Department of Biosystems and Agricultural Engineering.
University of Minnesota Extension Service. Room 213 Agricultural
Engineering Building, 1390 Eckles Avenue., St. Paul, MN 55108.
(612)625-7733 Fax: (612)624-3005.
www.bae.umn.edu/
Minnesota Department of Agriculture (MDA)
625 Robert Street North, St. Paul, MN 55155-2538. (651)201-6000.
General Composting Questions:
Matt Drewitz, Senior Planner, Agricultural Resources Management
and Development Division: (651)201-3820
Emergency Response and Catastrophic Losses:
Heidi Kassenborg, Emergency Response Director, Food and Dairy
Division: (651)201-6625
Michele Puchalski, Hydrogeologist, Incident Response Unit, Pesti-
cide and Fertilizer Division: (218)444-3403
www.mda.state.mn.us
Minnesota Pollution Control Agency (MPCA)
To find the regional office closest to you, contact the MPCA at
520 Lafayette Road, St. Paul, MN 55155-4194. (651)296-6300.
MPCA website: www.pca.state.mn.us
MPCA Feedlot website: www.pca.state.mn.us/hot/feedlots.html
University of Minnesota
David Schmidt, P.E.
Department of Biosystems and Agricultural Engineering Dept.
1390 Eckles Avenue, St. Paul, MN 55108-6005, 612-625-4262
www.bae.umn.edu/
Emergency Number
for Catastrophic
Animal Loss:
Minnesota State Duty Officer
651-649-5451
Minnesota Department of Agriculture
30
University of Minnesota Extension and Outreach Centers
U of M Southern Research and Outreach Center.
A composting demonstration site using swine, cattle, and
sheep. 35838-120th Street, Waseca, MN 56093-4521.
(507)835-3620. Fax: (507)835-3622.
http://sroc.coafes.umn.edu/
U of M Southwest Research and Outreach Center
23669 130th Street, Lamberton, MN 56152
(507)752-7372 Fax: (507)752-5097
http://swroc.coafes.umn.edu/
U of M West Central Research and Outreach Center.
A composting demonstration site using swine and cattle.
46352 State Highway 329, Morris, MN 56267-0471.
(320)589-1711. Fax: (320)589-4870.
http://wcroc.coafes.umn.edu/home.html
U of M North Central Research and Outreach Center.
A composting demonstration site using swine and cattle.
1861 Highway 169 East, Grand Rapids, MN 55744.
(218)327-4490. Fax: (218)327-4126.
http://ncroc.coafes.umn.edu/
U of M Northwest Research and Outreach Center
2900 University Ave., Crookston, MN 56716
(218)281-8604 Fax: (218)281-8603
http://nwroc.umn.edu/index.htm
United States Department of Agriculture-Natural
Resources Conservation Service (USDA NRCS)
375 Jackson Street, Suite 600, St. Paul, Minnesota 55101
(651) 602-7900
National USDA NRCS website:
www.nrcs.usda.gov/
Minnesota USDA NRCS website: www.mn.nrcs.usda.gov/
Composting Animal Mortalities
31
FURTHER RESOURCES
Publications and Web Sites
Animal Disposal Web Page.
Minnesota Department of Agriculture.
www.mda.state.mn.us/composting/default.htm
Composting Animal Mortality Resource Notebook.
Lynn Carpenter-Boggs, editor. 1999. Miscellaneous publication
number 100-1999. Minnesota Agricultural Experiment Station.
St. Paul, MN. Available from the West Central Research and
Outreach Center, 46352 State Highway 329, Morris, MN 56267.
(320)589-1711. Fax: (320)589-4870.
http://wcroc.coafes.umn.edu/
Carcass Disposal Web Page.
Minnesota Board of Animal Health
www.bah.state.mn.us/animals/carcass_disposal/carcass_disposal.htm
Dis-Solving Swine Mortality Problems.
2001. Iowa State University. Available from ISU, Department of
Agricultural and Biosystems Engineering, Ames, IA 50011.
www.abe.iastate.edu/PigsGone/index.htm
Guidelines: Land Application of Manure for Water Quality
Protection.
1996. Minnesota Pollution Control Agency (MPCA). Available
from MPCA-Nonpoint Source Compliance Section, 520 Lafayette
Road N, St. Paul, MN 55155-4194. (651)296-6300.
Minnesota Livestock Producer’s Feedlot Planning and Opera-
tions Manual.
2002.: Agricultural Resources Management and Development
Division, Minnesota Department of Agriculture, 625 Robert Street
North, St. Paul, MN 55155-2538, (651) 201-6520
www.mda.state.mn.us/feedlots/feedlotguide.htm .
Minnesota Board of Animal Health Rules.
Available from the Minnesota Board of Animal Health, 625 Rob-
ert Street North, St. Paul, MN 55155-2538. (651)296-2942. Fax:
(651)296-7417. www.revisor.leg.state.mn.us/arule/1719/4000.html
Minnesota Department of Agriculture
32
On-Farm Composting Handbook.
Robert Rynk, editor. 1992. NRAES-54. Available from the Natural
Resource, Agriculture, and Engineering Service, Cooperative Exten-
sion, 152 Riley-Robb Hall, Ithaca, NY 14853-5701. (607)255-7654.
Fax: (607)254-8770. E-mail: NR[email protected].
www.nraes.org/publications/nraes54.html
Swine Composting Facility Design.
1997. Ohio State University. Factsheet AEX-713-97. Available from
OSU Department of Food, Agricultural and Biological Engineering,
590 Woody Hayes Dr., Columbus, OH 43210.
http://ohioline.osu.edu/aex-fact/0713.html
Swine Mortality Composting Module.
Kellie McGuire, editor. NPPC National Office
10664 Justin Drive Urbandale, IA 50322. (515) 278-8012 .
Fax: (515) 278-8011.
www.nppc.org/
Thermometer Suppliers
Suggested: a bimetal composting thermometer with a 20-36 inch,
heavy duty 3/8 inch diameter stem, with a back connected, three inch
dial with a temperature scale of 0 to 200
o
F. Cost: $11 to $90.
Nasco Farm & Ranch.
901 Janesville Ave., P. O. Box 901, Fort Atkinson, WI 53538.
(800)558-9595. *Product number C14312N, baled hay and compost
thermometer, 20 inch stem for about $11.50.
www.enasco.com/
Reotemp Instruments Corp.
10656 Roselle St., San Diego, CA 92121.
(858)784-0710.
www.reotemp.com
Tel-Tru Manufacturing Co.
408 St. Paul Street, Rochester, NY 14605. (800)232-5335.
www.teltru.com
Trend Instruments, Inc.
1000 Wiegand Blvd., Lawrenceville, GA 30043. (888)WIKA-USA.
www.wika.com
Weksler Instruments.
(800)328-8258.
www.weksler.com/
Composting Animal Mortalities
33
BIBLIOGRAPHY
Carpenter-Boggs, Lynn, editor. 1999. Composting Animal Mortality
Resource Notebook. Miscellaneous Publication Number 100-1999.
Minnesota Agricultural Experiment Station. St. Paul, MN.
Carter, Thomas A., et al. 1996. Composting Poultry Mortality.
Publication Number PS&T-47. North Carolina Cooperative
Extension Service. Raleigh, NC.
Collins, Eldridge R., Jr. 1996. Composting Dead Poultry.
Publication Number 442-037. Virginia Cooperative Extension.
Blacksburg, VA.
Fulhage, Charles. 1996 (Reprint). Composting Dead Swine.
Publication WQ351.University of Missouri Extension Service.
Columbia, MO.
Glanville, Thomas D. 2001. Dis-Solving Swine Mortality Problems.
Iowa State University, Ames, IA. ae.iastate.edu/pigsgone/
Glanville, Thomas D., and Darrell W. Trampel. 1997. Composting
Alternative for Animal Carcass Disposal. Journal of the American
Veterinary Medical Association. Vol. 210, pages 1116-1120.
Langston, John, Karl VanDevender, and Jack C. Boles, Jr. Undated.
Disposal of Poultry Carcasses in Arkansas. Cooperative Extension
Service, University of Arkansas. Little Rock, AR.
McGuire, Kellie, editor. Undated. Swine Mortality Composting
Module. National Pork Producers Council. Clive, IA.
Mescher, Terry, et al. 1997. Swine Composting Facility Design.
Publication AEX-713-97. Ohio State University Extension.
Columbus, OH.
Minnesota Board of Animal Health Rules.
Chapter 1719.0100 - 1719.4600.
Walker, Roger, and Bill Crawford. 1997. Composting Swine
Mortality in Minnesota. Presented at 1997 University of Minnesota
Pork Conference. University of Minnesota. St. Paul, MN.
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The management of animal mortalities is an important aspect of
livestock farming since even the best livestock farmers lose some
of their animals each year. Rendering, burial, and incineration
have been the typical carcass disposal methods. However, these
options are becoming less practical for many farmers because of
decreasing availability and higher costs of rendering, biosecurity
concerns, and potential adverse effects on groundwater and air
quality. For these reasons, composting is becoming more widely
used as a method of mortality disposal. A properly managed
mortality composting system is low cost, environmentally sound,
biosecure, and virtually odor free.
While there is much in favor of composting, you must decide
whether or not it fits into your operation. Minnesota Board of
Animal Health regulations allow composting of poultry, swine,
sheep, and goats without a permit, and cattle can legally be
composted if a permit is obtained. Like any other farm operation,
successful composting requires a commitment to managing it well.
This publication describes mortality composting, answers
commonly asked questions, outlines what is needed to compost
on your farm, explains how to compost step-by-step, and outlines
applicable regulations. It also contains resources for more information.
Minnesota Department of Agriculture
Agricultural Development Division
90 West Plato Blvd., Saint Paul, MN 55107
www.mda.state.us
