Composting is now accepted as an environmentally safe and sound method for managing the carcass disposal of our deceased animals. Over the last decade, several events have forced the livestock industry to explore, develop and perfect new and safe methods for carcass disposal and remediation.
Every year, approximately 1% of the mature horse population (about 90,000 horses) in the US dies or must be put down. The current economic situation has increased pressure on horse owners who cannot afford to feed and maintain animals. Owners, adoption facilities, and rescue operations are not able to find adequate homes for all animals, leaving euthanasia as a respectable, dignified manner to end their lives. Increased bans on horses going for slaughter have made the disposal of unwanted animals more challenging.
For most of us, shipping horses to slaughter has never even been a consideration. When it comes time to plan for our friends’ final good-bye, we must explore the options. Historically, many of us have called in the backhoe operator. Burial though, is not without its health considerations. When animals are buried, the primary considerations are protection of ground and well water, and (in the era of “global warming”) the emission of methane gas from the anaerobic decomposition of the body (methane gas is 23 times more powerful as a greenhouse gas than CO2).
Composting, even of horses, is really quite easy. It is an aerobic process that allows naturally occurring microbes to recycle the entire animal back into humus, water, CO2 and heat. An important fact to remember is that horses, like humans, are more than 90% water. The bulk of their muscle and tissue is protein; in composting terms, that means nitrogen.
When aerobically composting other materials such as manure, yard trimmings and food waste, we try to create a blend of Carbon-based to Nitrogen-based materials in a ratio of 25:1 to 35:1. When composting an entire animal, the primary material we need is carbon, best found in wood chips. Call a few local Garden Centers, or check your Yellow Pages for tree surgeons or utility line maintenance. If you anticipate the need to put a horse down, stock piling wood chips in advance is a great thing to do. Usually, the tree service companies will drop off the wood chips for free or at a very reasonable price. Have the chips dropped near the composting site.
The mortality composting process is almost odorless if done properly. A few basic considerations will make it safer and easier:
* Your composting site should be at least 100 feet from any water source and 200 feet (ideally) from a drinking water well head or source.
* Create a structure within which the composting will be done. The containment vessel perimeter should be at least 8’x8’ for a large pony and 10’x10’ for a mature horse.
* The best way to construct these perimeters is to use either large round bales placed end to end, or use straw or non-feed quality hay bales placed 2-3 bales high. These will help keep wood chips in place.
* Once the bales are in formation, place at least 2 feet of wood chips (level) in the containment area.
* If you have an active compost pile or even fresh decomposing manure, place a 6-inch layer on top of the wood chips. The active compost and decomposing material will help inoculate the area with microbes, jump starting the process.
* Once the animal has been euthanized, place it on top of the chips and compost. Make sure that head and legs are at least two feet from the outside edge with the main body as close to the center as possible.
* Cover the body with another 6 inches to 1 foot of compost or decomposing manure.
* Last, cover the body with at least 2 feet (preferably 3) of wood chips. This acts as a bio filter and controls odors.
In the case of horses and cows, the entire decomposition process takes about five to six months, less in warmer climates. At the end of this period there will be nothing remaining except a few bone fragments.
After six months, use the tractor bucket to turn and flip the chips; this helps add oxygen and homogenize the mix. Let it sit another few weeks. Most of the chips should be humus and compost material at this point. This compost mix can then be safely field applied, returning your fine equine friend to the earth.
Josh Nelson started Beaver River Associates in 1987 and it soon became the largest worm composting operation in New England. Beaver River is the main supplier of worm composting supplies to Washington State University and Josh actively consults with municipalities in the northeast on organic waste recycling.