Proper Disposal of Dead Animals on Michigan Farms

The Bodies of Dead Animals Act (BODA) is important for many reasons, not least to protect human as well as animal health, according to Dale W. Rozeboom from Michigan State University's Department of Animal Science.
calendar icon 2 December 2009
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The Bodies of Dead Animals Act (BODA; Act 239 of 1982, as amended) regulates the management of dead animals in Michigan. The intent of this law is to:

  1. protect human and animal health
  2. reduce risk of disease transmission
  3. control flies, vermin and scavenging animal problems, and
  4. protect ground and surface water and air quality

A person violating BODA is guilty of a misdemeanour punishable by a minimum fine of $300 or imprisonment for a minimum of 30 days, or both. Three or more convictions for violating BODA is a felony punishable by imprisonment for up to one year or a fine of up to $2,000, or both.

Under this act, there are currently six alternatives for dead animal disposal in Michigan:

  1. burial
  2. incineration
  3. rendering
  4. land-fill
  5. composting, or
  6. anaerobic digestion (Pending promulgation of rules)

MDA may require an alternative disposal method, at the owner’s expense, if all of the current disposition methods for dead animals inadequately address potential toxicological contamination threats to human or animal health, or to the environment.

Regardless of which method of disposal is being used, all mortalities must be disposed of within 24 hours after death. The three exceptions to this rule are:

  • dead animals stored secure at less than 40°F for no more than seven days or at less than 0° F for no more than 30 days
  • small mammals, deer and birds taken under the authority of a damage and nuisance animal control permit issued by the MDNR (Part 401, NREPA, 1994 PA 451, MCL 324.40101 to 324.40119), and
  • road kill.

Mortality must only be those animals ‘intrinsic to an operation under common ownership or management.’ Carcasses may originate from multiple farm sites and be a mixture of livestock species, if all are owned by the same person or firm.

Dead animals may be transported from several sites as long as BODA rules for transport are followed. Vehicles and/or container(s) cannot leak or spill, and must be covered so that public viewing of the dead animals is not possible.


Burial sites must have no contact with bodies of water; both surface and ground, and must be at least 200 feet from wells. Frozen ground makes burial difficult in winter.

Individual graves must be:

  1. at least two feet beneath the natural surface
  2. limited to 100 graves per acre or five tons of tissue per acre
  3. separated by a minimum of 2.5 feet, and
  4. closed within 24 hours of opening

Common graves must:

  1. be limited to 2.5 tons of tissue per acre
  2. be separated by minimum of 100 feet
  3. have each day’s mortality covered with minimum of one foot of soil
  4. not remain open for longer than 30 days, and
  5. have at least two feet of soil as final cover.


Burning must not cause a public nuisance. Act 451, Part 55 ‘sources of air pollution’ states that incinerators must be permitted by Air Quality Division of MDEQ. Residues from the burning process must be buried as outlined above, land-applied at agronomic rates or properly disposed of in a land-fill licensed by the MDEQ.


Rendering services must be provided by a licensed dead animal dealer, rendering plant or animal food manufacturing plant. As of 27 April 2009, rendering facilities are required to remove the brain and spinal cord of all cattle ages 30 months and older if by-products are to be used for animal feed. FDA is trying to lessen the chance of bovine spongiform encephalopathy getting into the human food supply. The rule presents new challenges for renderers and farmers, including documenting and identifying such animals.


Farmers should contact local landfills to learn if they will take delivery or pick-up farm mortality. The number of Michigan landfills that take dead animals has been decreasing and may currently be 10 or less. Arrangements can be made for carcass pick-up by the waste management firms, but they must comply with provisions for transportation as written in BODA. If a farmer delivers to the landfill, BODA rules for transport must be followed and the risks of transporting disease from the landfill site back to production facilities need to be addressed in a the farm’s biosecurity plan.


This is the biological decomposition of animal tissues under controlled or managed conditions. After composting, soft tissues should not be recognisable, bones should be broken in small pieces, and the compost should be aesthetically acceptable to other people.

All composting rules under BODA must be followed. A comprehensive document named the Michigan Animal Tissue Compost Operational Standard (MATCOS) was written to explain in detail the composting options provided to farmers in BODA. These may be found on the MSU web site [click here].

Under BODA, mortality composting on-farm may be done in piles or in-vessel. Piles may take shape: in bins, in open piles, in overlapping piles or in windrows. With any of these methods, aeration of the compost material may be forced (mechanised with fan and ductwork), active (mechanical turning of material), or passive (air exchange within the composting material as fresh air is pulled into the lower portion of the pile as heat takes gases out of the upper portion of piles).

For smaller farms with 20,000 pounds or less of mortality annually, composting may be done in piles on bare soil without floor or roof (a.k.a. ‘open’). The soil must be land used for crop production. Collection of compost leachate is not required, but it must not cause a violation of any other federal, state or local laws.

For larger farms, with more than 20,000 pounds of mortality annually, open piles or windrows may also be used, but they must be on a concrete pad or liner which is laid down according to the NRCS 313 practice standard. Using a concrete pad or liner with open pile and windrow compost ensures adequate environmental protection and provides a solid surface year-round for driving of large equipment even with freezing, thawing and precipitation.

Site selection is important. On-farm traffic patterns, equipment access, animal housing, feedstuff movement and adequate space around the compost materials for loading, unloading and mixing should be considered. All composting sites must meet the following criteria:

  1. well drained soil with a minimum setback of 200 feet from waters of the state such as lakes, streams, wetlands, sinkholes, seasonal seeps, or other ‘hydrologically sensitive’ areas
  2. a minimum of two feet above the seasonal high water table
  3. a minimum of 200 feet from any well, and
  4. a minimum of 200 feet from the nearest non-farm residence.

Management of active composting is required to be done under the conditions:

  1. carbon-to-nitrogen ratio: 15:1 to 40:1
  2. moisture content: range of 40 to 60 per cent, and
  3. oxygen concentration of greater than five per cent, which accompanies a compost density in the range of 800 to 1200 pounds per cubic yard.

All composting systems require the controlled formation, identification and management of compost batches. BODA requires that each batch undergoes a minimum of three heat cycles over 130° F before final utilisation as ‘finished’ compost. Timely aeration and moisture additions will allow active composting to continue in repeated heat cycles for months and minimise total composting time.

Bulking agents (a.k.a. feedstocks, amendments, carbon sources) are organic materials placed around carcasses to provide nutrients, desirable density, and aeration. An approved list of bulking agents is given in BODA.

Flies, rodents, pests, vermin and other scavengers or predators must be controlled so as not to disrupt the compost or constitute a risk or health hazard to human or animal populations. A biofilter, or layer of fresh, bulking agent, placed over a pile after each addition or each aeration, reduces odors and discourages pests. Carbon-rich materials such as chopped bean stover, chopped corn stover, chopped straw, dried grass, grain hulls, chopped dried hay and sawdust or shavings should be used as biofilter materials. Animal manure solids, partially decomposed feedstocks, green grass clippings, fresh hay, green leaves, and litter cake are less effective in controlling odours, insects, and vermin and should not be used as a biofilter.

Finished compost should have no visible pieces of soft tissue when reused in new compost batches or spread on cropland. Large bones of mature animals generally take two to three times as much time as soft tissues to compost. Bones should be placed in a new batch of compost for further decomposition until easily crumbled during the mechanical spreading process. Finished compost need not be fully cured.

Records containing all of the following information must be kept by the owner or operator of the composting facility for a minimum of five years and must be made available to MDA immediately upon request.

  1. the start date of each compost batch
  2. date of and approximate weight of dead animal additions to new compost batches. Animal tissue additions to a new pile should be concluded in two months or less to facilitate proper management of the compost batches
  3. the internal temperature of each actively composting batch measured weekly, except twice per week for a rotat ing drum, continuous flow, in-vessel system. The internal temperature of curing material measured once each week
  4. the date compost material is aerated if done with loader or turning equipment, and
  5. the final use or distribution of finished compost, including the method, location, date and volume for the batch.

Cooperative or Commercial Composting

Michigan currently does not have language in its regulations allowing for cooperative and (or) commercial animal tissue composting. MDA, MDEQ and MSU are currently giving consideration to the regulation of both options.

Anaerobic Digestion

Anaerobic digestion was approved as an alternative in the past year (BODA, Amended 2008, Act 311, effective 18 December 2008), but is not currently allowed to be used as Part 665, Sub 15 states that the Department of Agriculture shall promulgate rules for the ‘methodology for the anaerobic digestion of organic materials.’ This process has not been completed.

Mass Carcass Disposal in a Major Animal Health Emergency

A memorandum between MDA, MDEQ and the Michigan Department of Natural Resources was entered into in September 2004 to define their respective roles and responsibilities when mass carcass disposal is needed because of a major animal health emergency, e.g. a foreign animal disease or a natural disaster). Work with your veterinarian quickly when you become aware of the potential for disease. BODA address only the normal and natural mortality occurring on a farm. Sub-rule 5 in section 19 of BODA says that any increase in normal natural daily mortality, due to any cause known or unknown, shall be reported to the MDA Director immediately. This is a biosecurity measure intended to protect our state’s and nations’ animal agriculture industry.

A document entitled Standard Operating Procedures for Michigan Mass Carcass Disposal is available [click here].

December 2009

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