Animal mortality management is not a popular discussion topic. However, the reality of animal agriculture is mortalities will happen in any livestock operation. While the losses are usually a small percentage (1-5%), illness, defects, age, and other natural causes will claim an occasional animal. Composting provides an option for livestock farmers to manage mortalities on-farm, in an immediate manor, any time of year.
The recent Animal Mortality and Major Disease Outbreak Management workshops reminded me that composting is an option for any size operation. A compost pile can be started any time of year with a little prior preparation. Even the smallest operation can easily be prepared to start a compost pile by identifying a suitable site and having a usable carbon source available. Planning and management are the keys to success.
The site selection for an animal mortality compost pile or bin involves finding a dry location away from neighbors and wells. Concrete or packed gravel are preferable for the base. Cleared, tight soil is an option for small/ emergency setups. Select a location that is level or slightly above grade, not where water will stand or a major flow toward/through it.
Carbon source options include sawdust, wood chips, corn residue, and poor quality forage bales. Small particle size is important to success, but particles still need enough structure to allow some air movement in the pile. Sawmill sawdust is too small; ground wood chips are ideal. Course wood chips, baled corn residue, and other baled forages/straw should be processed through a chipper or grinder to reduce article size to improve the process.
Once site and carbon source are selected, animal mortality composting can be started when the necessity arises. Place at least 6 inches of carbon material down on the base. Lay the animal(s) near the middle and cover with 12 inches of carbon material above and around the carcass. To ensure proper heating, the pile should be at least 3 feet high and 3 feet across the base.
Proper and quick composting will be achieved through management of the pile. The pile should heat to internal temperature of 130 to 160 degrees on its own initially. After a few weeks, the pile will start cooling; stir the pile to add oxygen and redistribute the carbon and nitrogen. This should result in another heating cycle within the compost. Usually, an additional stirring or two will be necessary to achieve completion of the composting process. In dry conditions, additional water may need to be added during the stirring process.
The final step is utilization of the material. As with any composting system, the compost is complete when no recognizable components of the parent material remain and has an earthy smell to it. A few heavier bones from large animals may remain. Most of these should be brittle, but can be put back through the process with the next compost pile to ensure complete breakdown. The compost should be applied to a crop field as a soil amendment for organic matter, minerals, and some nutrients.
This is a quick overview of the process to get producers thinking about the option. To learn more about the process or to contact Extension staff for more information, check the Animal Mortality Composting page at extension.illinois.edu/lfmm/animal-mortality-composting-workshop. You can access this and other livestock facility management information from the Livestock Facilities and Manure Management website, extension.illinois.edu/lfmm.
Stanley (Jay) Solomon, Jr. is University of Illinois Extension educator, environmental and energy stewardship