Summary of New OMAF Factsheet On-farm Composting of Livestock and Poultry Mortalities
The proper disposal of livestock mortalities is critical in preventing environmental contamination and the spread of disease. In Ontario, the Dead Animal Disposal Act (DADA) regulates the disposal of dead farm animals, specifically cattle, swine, sheep, goats and horses.
Under DADA, producers are required to properly dispose of on-farm mortalities in a safe and environmentally friendly manner within 48 hours of death. The act permits the following three disposal methods:
Pick-up by a
provincially licenced deadstock collector
Burial under 0.6 m (2 ft.) of soil on farm
Composting on farm.
There are several composting system options. The composting bin unit is an effective on-farm system that could be made with hay or straw bales.
What is
Composting?
Composting is a natural process by which micro-organisms, such as bacteria and
fungi, break down organic material into a stable product that can be applied
to land.
It can be a practical, environmentally sound and cost effective way for livestock and poultry producers to dispose of mortalities. If done properly, there is no odour or excessive leachate.
Planning
Your Composting Unit
There are several factors to consider in the planning and design of an on-farm
composting unit.
Site selection Select a level, well- drained location away from wells, watercourses
and tile drains. The site should also be easy to access so you can properly
manage and monitor the unit. Check with the chief building official and by-law
officer in your municipality to make sure you understand and can comply with
the environmental guidelines and regulations for your area.
Size of unit A composting unit consists of two primary bins, one secondary
bin and storage space for a high carbon substrate, such as wood mulch or straw,
and finished compost. The size of the composting unit will depend on the size
and nature of your operation. Some large farming operations may require more
than one unit. Calculations will need to be done on a farm-by-farm basis.
Construction A number of structures lend themselves to efficient on-farm
composting, including newly built, stand-alone units and renovations or add-ons
to existing buildings. The base and walls of bin composting systems should be
impervious. A roof will help to control moisture levels by protecting the composting
pile from rain and snow.
The Mechanics
of Composting
A complete composting cycle has three main stages: bin filling, the primary
heating stage and the secondary heating stage. In a typical situation, one primary
bin in a composting unit is filled over several months with mortalities placed
between layers of substrate. When full, the first primary bin is left to heat
while the second primary bin is filled. Once the first primary bin has finished
heating, it is moved into the secondary bin to incorporate oxygen and start
the secondary heating stage. At this time, the second primary bin (now full)
is left for its primary heating stage. After emptying the first primary bin,
you can start to fill it again to begin another composting cycle. One full cycle
may take 5 to 9 months, depending on the size and type of mortalities. Large
bones take longer to compost so you may need to screen them out of the compost
and add them to the primary bin being filled.
| Getting
Ready to Compost There are four essential components of an effective composting process. Carbon and Nitrogen in Balance The carbon to nitrogen ratio (C:N ratio) is critical for providing the required environment for the micro-organisms. A high-carbon substrate is needed to balance the high nitrogen content of mortalities. Clean sawdust has proven to be an excellent substrate for composting mortalities, although other materials with high carbon content such as wood mulch, straw, corn cobs, and corn silage may be used. At least 1.5 kg of substrate is needed for each kg of mortality for a high carbon substrate such as sawdust. Oxygen Oxygen must be available in the pile to support necessary microbial activity. The size of the substrate particles influences the amount of oxygen in the compost pile. Moving the pile from the primary bin to the secondary bin incorporates oxygen into the pile so composting can continue. Moisture An adequate moisture level is also needed to ensure proper microbial activity in the compost pile. You may need to add moisture or substrate to adjust the moisture level. Temperature Heat is the result of the composting process and is necessary for composting to work. For proper composting, the temperature in each heat stage must reach at least 55°C (131°F) and remain there for several days or weeks, depending on the size of the mortalities. |
Monitoring
the Compost
It is important to monitor the substrate cover, temperature and moisture, and
record the information. Throughout the composting cycle, you will also need
to watch for and take steps to prevent scavenging by animals, excessive leachate
and odour.
Finished
Compost
Properly finished compost has a slight earthy odour and resembles humus, or
potting soil, in colour and texture. A nutrient analysis
of the finished compost will accurately determine nutrient content so you can
include the compost in your nutrient management plan or strategy.
Get the
New Factsheet
Find more detailed information about establishing and maintaining a composting
unit in the new On-farm Composting of Livestock and Poultry Mortalities document.
It is available now on the OMAF website at www.omaf.gov.on.ca.
It will be printed as a factsheet by November 30, 2003. To get your copy, call
1-888-466-2372 or order it by email at products@omaf.gov.on.ca.
Gary
Koebel, former livestock mortality specialist, retired at the end of September.
Bill Groot-Nibbelink, Livestock Regulatory Affairs Specialist, has taken responsibility
for some of the livestock mortality specialist work, in addition to his other
duties. Bill works out of the Brighton OMAF resource centre and can be reached
at (613) 475-5887.