Managing dead animals is not pleasant, but is a necessary task for most livestock and poultry farms. This video discusses several options for disposing of carcasses in an environmentally responsible manner.
In most states, commonly approved disposal options include: burial, landfills, incineration, rendering and composting.
Perhaps the most common method of disposal is burial. Most states have regulatory burial guidelines outlining site location, distance from waterways, depth to groundwater, etc. When proper guidelines are followed, burial is a safe option. However, poor site selection, such as sandy soils or areas with high water tables, may pose a threat to groundwater. Furthermore, burial does not convert the carcass into a valuable by-product. Variable equipment and labor costs will influence the economic viability of this disposal option.
Disposing of carcasses at a licensed landfill that accepts animal mortalities is another form of burial. Landfills may require notification before delivery and/or documentation from a licensed veterinarian stating the cause of death. Landfill tipping fees should be assessed and may range from $20 to $30/ton. Other considerations are transportation costs and breeches of biosecurity by moving carcasses off- farm. Similar to burial, a valuable by-product is not produced.
Incineration is a safe and effective means of carcass disposal, especially from the standpoint of biosecurity. The carcass is completely consumed by fire and heat within a self-contained incinerator utilizing air quality and emissions controls. Some states may require air quality permits. Incineration is mainly designed for smaller carcasses and fuel costs should be considered. Due to odor and emission concerns, open air incineration (burning) is not recommended and banned in some states. Furthermore, obtaining complete consumption of the carcass in a timely manner is often difficult to achieve. Burning should only be used in emergencies for controlling infectious or contagious diseases with permission from a regulatory body.
Another recommended carcass disposal method is rendering. This is a heat driven process that cooks the product while killing pathogens and converting it into a value-added product such as an animal feedstuff. These feedstuffs, such as meat and bone meal, are generally used as pet food ingredients. Although rendering is a very effective method, currently, there are few rendering services available. The transportation expense of collecting small volumes creates a financial obstacle for most rendering companies. Some rendering facilities require the producer to transport carcasses to the plant and pay a fee. Biosecurity and disease transmission risks should be considered when allowing vehicles on the farm and when transporting carcasses off-farm.
Composting dead animal mortalities is an inexpensive, biosecure and environmentally sound approach to addressing the issue of carcass disposal. By definition, composting is a controlled biological decomposition process that converts organic matter into a stable, humus-like product. The carcass (nitrogen source) is buried in a bulking agent (carbon source), such as wood shavings, allowing for the proper carbon to nitrogen ratio (C:N) required by microorganisms to successfully decompose the carcass while absorbing excess moisture and filtering odor. The high temperatures achieved through proper composting will destroy most pathogens. Microorganisms will degrade the carcass leaving only a few small bone fragments, which are brittle and break easily. This valuable by-product can then be land-applied as a fertilizer source, adding nutrients and organic matter to the soil or recycled for new compost piles. As with burial, site selection is important. The site should be located in an area that does not pose a risk to surface or groundwater contamination.
Alternative methods are not specifically defined. They may include homogenization, digestion or chemical processes and technologies to recover products from mortalities.
Check out the other video FAQs on carcass management
Author: Joshua Payne, Oklahoma State University
Reviewers: Shafiqur Rahman, North Dakota State University and Jean Bonhotal, Cornell University