On Farm Mortality: Consider Composting

Many horse owners will eventually face tough decisions regarding animal mortality and disposal. The Unwanted Horse Coalition receives many calls from concerned owners regarding the legalities and options for disposing of horse carcasses. The problem arises with the diminishing disposal options for animals and livestock. Burial is not legal in all areas, many landfills do not accept animals, rendering plants are not accepting as many animals and are now charging larger fees and incineration is expensive. What other legal options do horse owners have, especially in today’s economy? Many farms are successfully using composting as a legal, beneficial, and inexpensive disposal alternative. The Unwanted Horse Coalition has researched the method of composting in order to assist horse owners during troubled times.

Shea Porr, PhD, superintendent of the Middleburg Agricultural and Research Extension Center, suggests composting as a disposal method for larger farms and facilities, "Composting works better on larger farms with a higher population of animals and farms that are isolated and not close to neighbors. I would not suggest this as an option for small farmettes."

Composting can be a relatively inexpensive process for livestock and farm owners, as most of the materials necessary for the process can already be found on farms. To successfully compost an animal, a front-end loader is needed, as are composting materials such as old hay, manure, grass clippings, chicken litter, rotten corn silage, and finished compost. Bobby Clark, an extension agent with the Virginia Cooperative Extension, estimates the cost of composting per head as $50-$75.

Farms can utilize the finished compost material to fertilize crops, re-vegetate barren areas, create forage, or compost other animal mortalities. If done successfully, composting can be extremely beneficial to farm owners; not only is it an inexpensive process, but the process is environmentally friendly.

When done correctly, composting can reduce an animal to just bones after 60-90 days. So, how is composting achieved?

In order to compost effectively, you need a porous material as a base layer to allow airflow, such as old hay, straw or woodchips. Next, you need a composting material such as manure, grass clippings, chicken litter, rotten corn silage, or finished compost. Successful compost material will heat to 131-161°F. The compost material should have a moisture level of about 50-70% and have a carbon to nitrogen ratio of 10:1 to 40:1. Lastly, you will need an insulating layer such as woodchips. To create a cost effective process, contact tree removal companies in your area to ask about the donation of unnecessary woodchips.

Creating the Compost Pile
The base material should be about 18-inches deep in order to process moisture and air effectively. The animal is placed on top of the base, and then completely covered with composting material. The insulating material, preferably 18-inches deep, will be placed last and cover the existing pile. The finished pile should be around 6-8-feet in height and have a peak or pyramid shape to allow rainfall and snow to shed, and to allow the correct amount of airflow to the compost. The pile should be turned once (with the front-end loader) and temperature should be checked often. The pile should reach 131°F or more for at least three days. If you happen to find sections of digging or traces of varmints cover the sections immediately. A successful compost pile will destroy all soft animal tissues, eliminate odors, destroy pathogens and protect human health and the environment after 60-90 days.

The Finished Product
After 60-90 days of composting at a successful temperature, moisture rate and carbon to nitrogen ratio, you may sift through the pile to see the remnants of the composted animal. The Virginia Cooperative Extension recommends:

  • Deep stacking the compost for an additional year to decompose bones.
  • Re-use of the finished compost in composting of additional animal mortality. This will facilitate the decomposition of bones.
  • Screening or grinding compost to remove the bones.
  • Applying finished compost to land or farmland. It is recommended that the compost be incorporated into the ground if bones are not removed or fully destroyed. The compost should be sampled and analyzed to determine the nutrient value to ensure it is applied at agronomic rates. If the mortality was euthanized by barbiturate overdose it is not recommended to land apply finished compost until more data is released. Further research is being conducted on the residual amounts of euthanasia solution remaining after the composting process.

Composting Laws
Be sure to research any laws or regulations governing composting in your state and locality. Laws will vary from place to place.

Consider Composting
Contrary to popular belief, composting can be done at any time of the year. Instead of throwing carcasses into the woods for potential scavengers and disease transmission, consider the low labor, low cost method of composting. Not only will you rid yourself of unnecessary materials on your farm, you may gain an environmentally safe material for future use on your land. For more information on composting, contact the Unwanted Horse Coalition at 202/296-4031.

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