For this reason it is imperative to be familiar with best management practices for dealing with dead animals. It is also important to understand that most states have 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.
The purpose of proper mortality disposal is to prevent the spread of infectious, contagious and communicable diseases and to protect air, water and soil quality. Also, 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 mortalities must be defined.
Unacceptable Animal Mortality Disposal
Though dragging off a carcass to the bone yard has been a historical practice, abandonment is not recommended and is likely illegal in many places. Examples include: carcasses abandoned on the surface, in 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
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.
This is probably the most 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.
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.
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 temperatures, attain proper decomposition and prevent scavengers. Nutrients and organic matter in finished carcass compost can benefit forest and crop land; however, nutrient management guidelines should be followed.
Prepared by Morgan Firestine