Step 1

Place 2 ft (60 cm) layer of co-compost material on the floor of the primary bin 1.
 

Step 2

Lay the carcass in the centre of the base on its back or side.
 

Step 3

For ruminants larger than 300 lbs (136 kg), it is recommended to cut open the thoracic, abdominal cavities, viscera, as well as, slice large muscle mass to accelerate the compost process and prevent possible explosion of the intestinal cavities. For non-ruminant animals, no lacerations are required. Before the animal is covered, wet the animal hair or fur with water; this provides good carcass to co-compost contact.
 

Step 4

Cover the entire carcass with at least 2 ft (60 cm) of co-compost material. The 2 ft layer of material will act as a biofilter to reduce unwanted odours. For more than one animal mortality, make sure there is at least 1 ft of co-compost between the carcasses.
 

Step 5

When adding more carcasses, skim the top layer down to 1 ft.
 

Step 6

Place the carcasses on top of the pile ensuring that the carcasses are not touching. It is recommended to leave approximately 1 ft of co-compost between mortalities. Once primary bin 1 is full you are in the primary stage. In this stage, the temperature should increase to 40-65°C. 
 

Step 7

Once primary bin 1 is full, start filling primary bin 2 following steps 1-7 above.
 

Step 8

Once the temperature in primary bin 1 stays above 40°C for seven consecutive days and then drops, the pile is ready to be emptied into the secondary bin (approximately 3 months). By this time the compost pile should contain bones and minimal flesh.
 

Step 9

Once the pile is turned you are in the secondary stage. The secondary composting period is usually equal to the primary composting time (approximately 3 more months). Monitor the pile daily, the composting process is usually finished after the temperature is greater than 55°C for seven consecutive days and then drops.  Check the pile, if there are no signs of flesh and only brittle bones left, the composting is done and can be applied on-farm.  If all of the flesh has disappeared, the compost from the secondary bin can be emptied out and spread on-farm.
 

Step 10

After approximately 3 months, the contents from primary bin 2 should be turned into the secondary bin (see diagram A).  If there are still signs of flesh in the contents in the secondary bin (remnants from primary bin 1), mix the contents from primary bin 2 with the contents in the secondary bin (see diagram B). Again, monitor the temperature daily, if the temperature is greater than 55°C for seven consecutive days and then drops (temperature drop should be close to ambient temperature) the compost should be finished.  If there are no signs of flesh, composting is complete.  Large bones may be present and can be sieved out and thrown back into a primary bin for further composting.

(A)

(B)

The Finished Product