Deadstock are normal
of raising sheep.
Simple compost bin
There is an old saying, "where there are livestock, there are
'deadstock'." Death is a normal part of any animal production enterprise.
Dead animals and other wastes (afterbirth and slaughter wastes)
can be a risk to biosecurity and hazardous to the environment. They need to be disposed of
in a proper manner to minimize soil and water contamination and
the risk of spreading disease and attracting wildlife.
Laws pertaining to the disposal of animal mortality
vary by location and species. Be sure to follow the laws of your
county, province, and/or state.
Depending upon location, disposal options may include incinerating,
landfills, burial, rendering, and composting.
Incinerating dead animals is an option, but may not be
economical feasible, except in very large operations. Some state diagnostic
labs and veterinary offices may incinerate dead animals for
a fee. Incinerating is energy-intensive and has the potential
for polluting the environment if the incinerator is not operated
and maintained properly. However, the ashes from properly incinerated
dead animals are harmless and do not attract rats, mice, or
In some locations, dead animals can be placed in sanitary landfills.
Before taking dead animals to a landfill, producers must check
to see if the landfill will accept dead animals. Even if a landfill
is permitted to take dead animals, it may not be the policy
of the landfill operator to accept dead animals.
Burial is still a common method of dead animal disposal, but it is becoming less preferred due to the
potential for water pollution. However, it may be the only practical
option for some producers. Burial involves digging a grave or
pit, filling it with the dead animal, and covering it with soil.
In time, the dead animals will decay. In cold climates, burial
is difficult when the ground is frozen.
Areas that have permeable soils, fractured bedrock, and a seasonable
water table must be avoided. The burial site must be located
away (at least 300 feet) from water sources and structures and
neighbors. It needs to be protected from scavengers. Not all
counties and states allow burial of dead animals.
Rendering usually recycles the nutrients contained in dead animals
into an ingredient for animal food, especially for pets. However,
lack of rendering plants and animal disease concerns make it
difficult to use this option.
In 1989, the rendering industry in the U.S. and Canada began
excluding sheep (1 year or older) from entering the rendering
system. This action was the result of the unsubstantiated claim by the British government
that rendered sheep carcasses (infected with scrapie) were the
cause of the mad cow disease outbreak.
Nowadays, it is even getting more difficult to have dead cows rendered, due to mad cow disease concerns.
Composting is rapidly becoming the preferred method of dead
stock disposal. Composting is an aerobic biodegradation process
used to decompose organic material. It transforms a waste product, such as manure and animal carcasses, into a useful soil amendment. Most
compost is spread on agricultural land.
Composting works well because it releases nutrients slowly during
the warm, moist solid conditions that encourage plant growth.
The compost N, P, and K should be considered part of the nutrient
management plan for the field. The compost generated from the
decomposition of animal carcasses should not be given or sold
as compost for use off-farm.
To make composting work, you need to create and maintain the
ideal environment for the microorganisms to function in your
pile. There are four essential elements for successful composting:
1) carbon and nitrogen; 2) oxygen; 3) moisture; and 4) temperature.
The carbon to nitrogen ratio (C:N) is very important to the composting
To facilitate the composting process, you will need to add a
substrate that is high in carbon to balance the high levels
of nitrogen contained in the mortalities. Too low a C:N ratio
may cause odors. Too high a C:N ratio may limit microbial activity,
resulting in lowered temperatures and slowed decomposition.
A C:N ratio ranging from 25:1 to 35:1 is ideal.
Clean sawdust has proven to the best substrate for composting
animal mortalities. However, other materials with high carbon
content can be used, such as straw, corn stalks, corn silage,
wood chips, straw-manure mixture, or old feedstuffs.
Oxygen must be present in the pile to support necessary microbial
activity. An adequate moisture level is also needed to ensure
proper microbial activity in the compost pile. The ideal moisture
content is 45 percent, but levels from 40 to 60 are acceptable.
Low moisture levels can reduce microbial activity while high
moisture levels inhibit the flow of oxygen and can lead to odors.
Heat is the result of the composting process and is necessary
for composting to work. The more heat there is, the more heat
is produced, and the faster the composting process. For proper
composting, the temperature must reach at least 131° F (55°
C) and remain there for several days or weeks.
Temperatures above 131°F for 72 hours are necessary to destroy
human pathogens and most plant pathogens. Extremely high temperatures
are detrimental to the composting procedure.
How to Compost
The practices of composting animal mortality are simple. You
start by constructing a base of sawdust or acceptable amendment
at least one foot thick. This base will collect fluids that
are released during carcass decomposition. Next, place the carcass
on the sawdust base. Cover the carcass with 1 to 2 feet of damp
amendment. This cover acts as a biofilter for odor control around
the pile and insulates the pile to retain heat.
When a new carcass is added to the pile, hollow out a hole in
the amendment, while maintaining 4 to 6 inches of amendment
over the carcass already in the pile. Place another carcass
on the pile. Cover the carcass with 1 to 2 feet of amendment.
Adequate depth of materials on top of the carcass should minimize
odors and the risk of scavengers disturbing the pile. To decrease
composting time and to allow the carcass to be laid flat, the
body cavity of the animal can be opened.
Composting Dead Sheep by David L. Greene =>
Common composting materials
Carbon to Nitrogen
| Source: various
Facility site is important to successful composting. A site
must be selected so that surface and ground water sources will
not be adversely affected. It is beneficial to locate the facility
away from neighbors and human dwellings. The facility should
be away from the production unit to lessen the risk of disease
transmission by rodents.
The composting pad should be firm but
does not need to be paved. A roof may or may not be necessary.
A tarp can be used to cover the pile during periods of excessive
rainfall. Usually only one bid is needed for a small flock of