Proper management of animal carcasses on the farm/ranch has implications in nutrient management, herd and flock health, as well as farm family and public health. It is imperative to be familiar with best management practices (BMPs) for dealing with dead animals. These BMPs may be dictated by state laws related to proper disposal or processing of mortalities. State departments of agriculture and regulatory agencies are great places to start looking for information on local laws.
Composting-Beyond the Basics:
Part 2 includes quality assurance and safety, euthanasia drugs, and pathogen and prion degradation.
Managing Mortalities in an Avian Influenza Outbreaks
Proper mortality disposal prevents the spread of infectious, contagious and communicable diseases and protects air, water and soil quality. There are legal issues and requirements related to nutrient management and the permitting of animal feeding operations. In the nutrient management plan, disposal of routine operational mortalities and catastrophic (when large numbers of animals die at once because of weather events, equipment failure or other reasons) mortalities must be defined.
Teachers and extension staff should check out the animal mortality curriculum materials for materials you can use in your classroom and programs.
Unacceptable Animal Mortality Disposal
Though dragging a carcass off to the boneyard has been a historical practice, abandonment is NOT recommended and is likely ILLEGAL in many places. This includes carcasses left to decompose in place, open pits, ditches, water features and sinkholes or in wells. Abandonment promotes extreme biological and disease hazard, threats to water quality, odors, flies, scavengers, rodents and visual pollution.
Methods of Animal Mortality Disposal
Disposing of animal mortality by open pyre burning is not recommended. Finding proper fuel to maintain temperature and flame is difficult; obtaining complete consumption of the carcass or carcasses in a timely manner is also difficult to achieve. Air emissions are uncontrolled and likely dangerous, especially depending on the fuel source. Burning should only be used in emergency situations with proper advisement and permission from a regulatory body.
This is a safe method of carcass management from a bio-security standpoint. Incineration is different from burning because it is intended for the entire carcass to be quickly and completely consumed by fire and heat. This practice must be done in an approved device with air quality and emissions controls. It is mostly limited to small carcasses (such as poultry) and can be energy intense. The cost of fuel can be an important factor in adopting this practice.
Burial is a very common method of dead animal disposal in many states, although it may NOT be allowed in some. Most states have regulatory burial guidelines outlining site location, distance from waterways, depth to groundwater, etc. If proper procedures are used, burial is safe; however the land owner should be aware that certain portions of carcasses can persist for years in an anaerobic environment. During construction projects on former poultry farms, old burial pits have been discovered that contain intact birds. Areas with high water tables and sandy soils do not allow proper depth or cover of burial without threatening ground water. Burial pits are considered mass graves and, if not managed properly, may pose additional risks to spreading disease and contaminating the environment.
Disposing of carcasses at a licensed landfill is considered a method of burial. Land filling may be an option in some areas; however, the legality of this will be based on the classification of the facility, local regulations and the policy of the individual site. Even if the landfill is classified to accept carcasses, the management must also grant permission. It is a good idea to have a written agreement if this method is to be utilized with any regularity. Even if permission is granted, drawbacks may include additional handling of the mortality, transportation and tipping fees, and breeches of bio-security.
Rendering is a heat driven process that separates and converts waste animal tissue into value-added materials. It is an easy method of mortality management for the farmer and it leaves no lasting legacy on the farm. However, there are very few rendering facilities across the U.S. There can often be fees and charges associated with a rendering service. However, if a producer has access to a rendering service and it is affordable, then it is a highly recommended practice. The cost of rendering should be weighed against time management, input cost, and possible bio-security breeches when compared to other available methods. Local farmers and the County Extension Agent may be the best resource for determining if this service exists in the area.
For many species, carcass composting is an environmentally preferable method of managing mortalities. When performed correctly, the end product may be incorporated into existing land application of manures. Much information is available on poultry composting and it is not an uncommon practice. It is also possible to compost larger carcasses. Many operations, even in cold climates, successfully compost larger stock including sows and full grown cattle. Related: What Carbon Source Can I Use To Compost Animal Mortalities?
Though composting of medium to large carcasses and land applying the material is proving to be feasible, this is NOT currently under consideration for goats and sheep due to the prevalence of scrapie, a prion disease, in flocks across the U.S. This disease is a transmissible spongiform encephalopathy (TSE) similar to BSE (mad cow disease) and the human Creutzfeldt-Jakob disease and poses a bio-security risk if compost from these animals would be spread on land. Fate of compost from sheep and goats should be carefully considered; seek local advice.
Technical procedures on composting cattle carcasses are available and continue to be studied and refined; this appears to be a viable option for the future. Most composting requires storm water protection and covering. Additional management and monitoring is required to refine the process, maintain high temperature and optimum moisture levels, attain proper decomposition and prevent scavengers and odors. Nutrients and organic matter in finished carcass compost can benefit forest and crop land; however, nutrient management guidelines should be followed. Contact your local Extension Office or USDA Service Center for information on designing and operating carcass composting facilities and best management practices. Related: How Much Does It Cost To Compost Animal Mortalities?
Alternative methods are not specifically defined. They may include homogenization, digestion or chemical processes and technologies to recover products from mortalities.
Catastrophic Mortality Events
These events can result from a variety of causes. Examples include a simple act of nature like a storm knocking out the barn ventilation system, an animal disease outbreak or even intentional agro-terror attacks. A producer’s plan to deal with mortalities during regular operations will likely be inadequate during a major event. All catastrophic events should be reported to appropriate agencies in a state, including federal agencies operating there. Likewise, assistance may also involve multiple agencies such as, federal and state emergency management agencies, environmental agencies and public health agencies.
If a catastrophic mortality event is the result of disease outbreak, bio-security considerations may dictate the method of transportation and disposal. At a minimum, a catastrophic mortality plan for an individual farm should identify a safe location onsite for burial, composting or other approved management technique. Many state and federal agencies are developing action plans for a variety of scenarios.
Additional reading on catastrophic mortalities is at: Animal Mortalities From Fire
Resources and Webcasts About Livestock and Poultry Mortality Management
- Frequently Asked Questions About Animal Mortalities
- Oklahoma State University fact sheet On Farm Mortality Composting of Livestock Carcasses
- June, 2009 webcast presentation on Managing Livestock Mortalities Discusses regulations and an overview of several methods with an emphasis on composting.
- LPES Curriculum Mortality Review
- Purdue Review of Methods
- Cornell University Mortality and Offal Composting
- University of Nebraska Lincoln compost spreadsheet tool
Authors and Reviewers
Page Authored and Maintained by: Thomas Bass, Montana State University, firstname.lastname@example.org; Joshua Payne, Oklahoma State University, email@example.com; and Saqib Mukhtar, Texas A&M University, firstname.lastname@example.org
Page Reviewed by: Jennifer Zwicke and Troy Chockley, USDA NRCS