In times of supply chain disruption, how do I appropriately dispose of my livestock mortalities?

Learn about mortality disposal options according to the Michigan Bodies of Dead Animals Act.

A man testing compost.
Composting animal mortalities can be timely, effective, and environmentally beneficial. | Photo by MSU Extension

When large meat processors are forced to close their doors due to employee sickness, the impact can be felt throughout the supply chain. Farmers who normally supply these markets are left with few options, often turning to small-scale meat processing operations. Many smaller processors are not equipped with the resources to absorb higher volumes of production. Limitations such as structural restrictions, fewer staff, limited capital and the lack of necessary equipment to operate such large volumes are often a challenge for smaller businesses. As a result, many livestock suppliers have nowhere to go with their livestock. Without an outlet for the supply, farmers may experience situations where alternative options are needed for their livestock. Michigan State University Extension has supplied some potential options for livestock producers in  Supply chain disruptions, the first article of this 3-part article series that describe methods to potentially implement before euthanasia is considered, realizing euthanasia may be the only option as a last resort. Should euthanasia need to be utilized, please reference Planning tool for welfare culling during farm disrupted operations, the second article in this 3-part article series for humane handling practices for animals being euthanized.

The COVID-19 pandemic has caused temporary processing plant closures, less food animal products consumed in restaurants, and less ability for producers to market animals into the food chain. Backups within the animal food chain can prevent the shipment of some healthy cull animals creating the potential for an increase in a farm’s normal and routine mortalities.

Michigan’s Bodies of Dead Animals Act (BODA) and its accompanying rules provide farmers with acceptable practices for the routine management of on-farm animal mortalities. Over time, the number of management options has increased. Some methods are completed on the farm while others are accomplished by moving dead animals off the farm. Which management plan you choose to use will depend on the availability of services, the suitability of sites, appropriately sized plans or methods for normal amounts of mortality, costs, timeliness, biosecurity and potential impact on the environment.

Timeliness matters. According to BODA, all mortality must be disposed of within 24 hours unless put into cold storage. Very few farms have cold storage facilities for mortality. Those that do may temporarily store a dead animal for a maximum of 7 days at a temperature of 40 degrees Fahrenheit or less or freeze a dead animal up to 30 days if the temperature of the storage is below 9 degrees Fahrenheit.

Off-farm disposal options

Off-farm dead animal disposal options are the most convenient options for a farm to consider. Licensed dead animal dealers (haulers) can remove mortalities from the farm. They then take the mortality to a landfill or a rendering plant. These are the two disposal options currently available with the services of a dead animal dealer. Biosecurity plans must be in place to protect the health of animals on the farm when using such services as these trucks move from farm to farm. Timeliness with this approach is most challenging, as the hauler may not be able to come to the farm within 24 hours.

Rendering

Rendering availability is based on volume and is used more often by large farms. Proximity to the rendering plant should also be considered. If a small farm has a temporary cold storage, rendering may be justifiable. Records of deliveries to rendering are not required by BODA, however they would be useful in secure supply planning for traceability purposes.

Landfill

A landfill may be used without the use of the services of a dead animal dealer. You must call the landfill ahead of time if you intend to bring the carcasses yourself. Some landfills accept dead animals, some do not. Transporting mortalities to landfills have biosecurity risks. As with rendering, records are not required by BODA, but may be useful for biosecurity and traceability reasons.

On-farm disposal options

On-farm disposal options have different advantages and disadvantages. Burial has been commonly used in the past. When considering the timeliness of this mortality option, be aware of the weather. Frozen and muddy ground can be difficult to construct a proper grave, so if possible, it is best to plan your burial during warm and dry weather. 

Burial

The biosecurity risks for burial are relatively low. Environmentally, BODA parameters for burial require that the entire animal carcass is buried at least two feet below the surface of the ground and can only be buried with the landowner’s permission. Furthermore, the carcasses should not be exposed to any bodies of water. Steps should be taken to determine if there is a high water table, because every 1,000 lbs. of carcass contains about 22 lbs. of nitrogen. It is also required that burial sites are located at least 200 feet from any well. There are two types of burial are allowed in the state of Michigan: individual graves and common graves.

  • Individual grave standards: no more than 100 individual graves per acre allowed with a combined total of five tons per acre. These graves must be separated by at least two and a half feet.
  • Common grave standards: the weight of all animal carcasses in a common grave may not exceed 5,000 lbs. per acre and if there is more than one common grave per acre, they must be separated by at least 100 feet.

The records should include dates, volume of mortality in pounds, location of burial, and common or individual grave. For MAEAP verification or Right to Farm investigation, a producer will be asked to produce these records.

Composting

Composting mortality can be timely, effective, and environmentally beneficial. Michigan State University Extension has two bulletins clearly describing how to compost mortality: Carcass composting - a mortality management option for Michigan equine owners - E3168 and Carcass composting - a guide to mortality management on Michigan cattle farms - E3197. Although written about composting horses and cattle, the details are applicable to properly compost all on-farm animal mortalities. Time and experience have proven that the use of overlapping piles under an open-sided pole barn facility works well. Bin and windrow composting are two other available composting methods some farms use.

Active composting is effective in destroying pathogens that cause disease, as pile temperatures will reach 130 degrees Fahrenheit to 150 degrees Fahrenheit. BODA requires three heat cycles that reach these temperatures. Aeration or turning of the compost begins the second and third heat cycle. Turning and mixing gives uniform exposure of the compost material to these temperatures. Activity is achieved using an acceptable recipe or compost mix. The carbon to nitrogen ratio and moisture content must be within acceptable ranges. Wood products, crop residue and other composting amendments must not be too coarse or too fine. BODA describes methods for preventing runoff and leachate from leaving the composting site, including site selection, shaping the pile correctly, covering the pile, and composing on a hard surface to prevent these liquids from getting into surface or groundwater. Regarding the use of barbiturates in the euthanasia of animals, if carcasses are composted appropriately and not directly consumed, the finished compost is safe for agriculture use. According to BODA, producers must maintain records of mortality composting.

Incineration

Incineration is another on-farm disposal option that works well because heat associated with incineration destroys pathogens. The size of the incinerator must match the daily accumulation of mortality. If too small, then disposal of all the day’s mortality could be delayed. If overloaded, the operating temperature may not reach the desired level, decreasing pathogen kill and increasing the release of undesirable emissions. It is also important to choose a location in which the burning does not cause a public nuisance and follows local ordinances. Residue or ash must be buried, land-applied at agronomic rates, or taken to a landfill. Records about incineration are not required by BODA, but may be useful in managing throughput and efficient use of the incinerator. An air use permit is required from the Air Quality Division of the Michigan Department of Environment, Great Lakes, and Energy (EGLE) for incineration.

Anaerobic digestion

Anaerobic digestion is the most recent method of on-farm mortality disposal approved in BODA. Energy is captured with this method, but the reduction of carcasses into pieces that fit digestion plumbing is a significant drawback. Consequently, this method may be most appropriate for neonates or very young animals, and not adults.

BODA does allow for other on-farm management approaches for normal or routine dead animals. These must be approved by the MDARD Director before being used.

MSU Extension recognizes and understands that the method of mortality disposal will differ between farm operations and encourages the use of sound practices with all of these disposal options. Having a set of standard operating procedures in place will help your farm to properly dispose of a dead animal when the time comes. It is also important to remember that records of farm mortality are required in BODA and any increase in mortality that is not normal must be reported immediately to MDARD. This is for the greater good of all animal industries in the state in the event of a highly contagious disease outbreak.

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