Progress With Composting as a Means of Swine Mortality Disposal
Livestock Update, January 2002
Allen Harper & Mark Estienne, VA Tech Tidewater AREC
Recently, on November 13, over 50 swine producers, nutrient management planners and Department of Environmental Quality inspectors converged on the Virginia Tech Tidewater AREC to participate in a half-day swine mortality disposal workshop. The workshop emphasized composting as a means to effectively dispose of normal mortality that occurs on hog farms. Some producers made the trip to southeast Virginia from as far west as Bedford, Buckingham and Halifax Counties. The strong interest in this topic and the willingness of producers to make long road trips to participate signifies the importance of this problem on working hog farms.
Even on well-managed farms with high herd health status, a small percentage of hogs and pigs will die. Traditional methods of dead hog disposal, including on-farm burial, on-farm incineration and transport to rendering plants, each have certain limitations. Burying hogs requires significant time, labor and digging equipment if done properly. Regulatory agencies are now discouraging burial of dead hogs following the recent discontinuance of burial as a means of dead poultry disposal for ground water protection reasons. On-farm incineration requires specialized incinerator equipment and also requires a separate permit from the Department of Environmental Quality. Transport to rendering plants increases health and bio-security risks when people and transport vehicles move to and from hog farms and the rendering plant. And some hog farms are just too distant from a rendering plant to justify this method of disposal.
Is composting right for your farm? Composting involves combining and fully covering nitrogen-rich hog carcasses with carbon-rich materials such as wood chips, saw dust, chopped straw, or peanut hulls. When the mixture is prepared to contain adequate air (oxygen) and moisture (about 50% to 60% moisture), thermophilic bacteria grow and cause increased temperatures (130 to 160 F) and rapid breakdown of the carcasses. Finished compost is a stable mixture of organic material that can be incorporated into a nutrient management plan and applied to cropland.
Experience with composting in other states and our demonstration work here at the Tidewater AREC indicate that composting is a viable means to dispose of dead swine that routinely occur on hog farms. Small pigs can be composted quite rapidly and in that regard are similar to composting dead birds on poultry farms. Sows and larger market hogs require more time, as much as 3 months in a primary composting phase and as much as 3 months following turning for a secondary composting phase. A few bones may remain when composting larger hogs but this material is usually easily broken and crumbled.
Initial investment will depend on the size and type of composting facility that is put in place. In Missouri, some producers have been successful in preparing temporary composting structures using large round bales to form open-front "bins" containing sawdust and dead pigs. Such a structure would have a relatively low initial investment cost. But a well-planned roofed structure with multiple bins allows better control of moisture conditions and the overall composting process. The demonstration unit constructed at TAREC contains 8 bins that are 5 _ by 8 by 5 feet in volume. This small unit would accommodate a finishing farm producing 3500 market hogs annually. It was constructed for a cost of approximately $8,000 including all building materials, delivery of ready-mix concrete for the floor, and extension of electricity and water service to the building. Larger hog operations would require a larger composting unit. An effort is currently on going to make state cost-share funds available for construction of swine mortality composting facilities similar to that available for poultry composting units.
Other equipment needed would include a front-end loader or similar implement for loading large hogs and turning compost. A means of mechanically spreading the finished compost onto crop fields would also be needed.
Producers who recognize the principles behind effective composting and plan accordingly can employ the method successfully. The following table summarizes general procedures for successful composting of swine mortality. For more detailed information on setting up a composting process to dispose of hog farm mortalities, contact Allen Harper by phone at 757-657-6450, ext 106 or email at firstname.lastname@example.org.
General Operating Procedures for Successful Composting of Swine Mortality.
|Site for composting||
|Sizing of compost unit||
|Management (Primary bins)||
|Management (Secondary bins)||