Carcass Composting –- Session Chair: Bill Seekins

The following abstracts were prepared for the Symposium on Composting Mortalities and Slaughterhouse Residuals

Portland, Maine

May 24-25, 2005

Evaluation of Composting for Emergency Disposal of Cattle Mortalities in Iowa

Thomas Glanville

Note: To see complete abstract, go to ABSTRACT FOLDER, CARCASS COMPOSTING FOLDER, Maine Livestock Disposal – pdf

Large Animal Mortality Carcass Composting Field Trials: 2001-2004

Submitted by:

Bill Seekins

Maine Department of Agriculture

State House Station

28 Augusta ME

Phone: 207-287-7531

E-mail: bill.Seekins@me.gov

AUTHORS: B. Seekins, M.A. King, M.L. Hutchinson, N. Hallee

INTRODUCTION

The Maine Department of Agriculture became aware of the outbreak of Foot and Mouth Disease (FMD) in Great Britain during the winter of 2001. The two Maine State Veterinarians and the Federal Veterinarian in Maine all spent time in England assisting with managing the crisis. Upon their returns to Maine, they reported on the devastation caused by the disease and the problems that resulted from trying to dispose of the thousands of carcasses. Their experience heightened the concerns already felt by the Department and by the Maine livestock industry about what would be done here if an outbreak occurred. A task force was established by the Commissioner of Agriculture to develop a plan of action to deal with such an emergency. One of the efforts of the task force was to evaluate the disposal options available and to develop a plan for implementing those best suited to the conditions in Maine.

The methods of disposal that were considered were:

  • burial
  • burning
  • rendering
  • composting

When these options were evaluated, each was found to have a weakness, or concern.

As a result of these findings, the Maine State Soil Scientist, David Rocque suggested that the compost process should be tried using hot, active compost instead of sawdust or shavings as the compost media. The reasoning behind this suggestion was that hot compost would already have an active microbial population that was breaking down organic material. The heat and active microbes would create an environment that should be very hostile to pathogenic organisms such as the FMD virus.

The task force felt that this idea had merit and requested the assistance of the Maine Compost Team* (Compost Team) in evaluating this approach. The Compost Team was already planning to conduct animal carcass compost trials using farm based compost and so gladly accepted the charge. They determined that the most readily available source of active compost would be the large compost facilities that composted municipal waste water treatment sludges (biosolids).

* Note: The Maine Compost Team includes: Mark King, Maine Department of Environmental Protection; Bill Seekins, Maine Department of Agriculture and Mark Hutchinson, University of Maine Cooperative Extension. Neal Hallee, formerly of the University of Maine Cooperative Extension was also a member of the team at the time the trials began.

Literature on FMD virus survival suggested that the FMD virus did not survive beyond about 8 days in either liquid or solid manure if the manure was at or above 32°C (90°F). It also indicated that survival time was shortened significantly with every 2°C rise in temperature above this level. It was hypothesized that survival in a compost environment would be similar if it could be shown that the internal temperature in the carcass could be raised to this level and maintained for at least eight days.

DESCRIPTION OF PROJECTS

The Compost Team set up a demonstration/research project at Highmoor Farm, a research farm owned by the University of Maine. Several sets of trials were conducted at Highmoor and at other farm locations in the state. The first was done in the summer of 2001, trying different approaches for composting. A second trial was conducted in the winter of 2001­2002. This second trial focused on using the most successful of the approaches tried in the Summer Trials.

Summer Trials 2001

Four different approaches were tried during the Summer Trials. The initial trials began on June 5, 2001. Four dairy cows and two calves were used in the initial trials. These trials were set up to determine if there was any difference between just covering the carcass with active compost and completely surrounding it with compost and if placing the piles in a trench offered any benefits. The trials were set up as follows: Two were done in trenches, one with compost under and over the carcass and the second on the soil with compost as a cover.

Two others were done above ground. One used farm compost materials above and below the carcass, while the other used the municipal sludge compost above and below the carcass.

Monitoring consisted of daily visits to the site by a Compost Team member, who took and recorded temperature readings and made observations about odors, vector activity, moisture conditions and general pile appearance.

On September 6, 2001, the Compost Team dug into each of the trial piles to examine the condition of the carcasses. The amount and condition of the soft tissue was determined and the bones were examined for indications of decomposition.

General Results of 2001 Trials

Throughout the project, the piles were watched for signs of leachate escaping from the piles. No moisture was observed leaving the piles at any time. Odors at the compost site were minimal throughout the project. The odor that was detectable on site most of the time, was the relatively mild odor associated with the compost materials themselves, not the carcasses. Vector activity at the site was minimal. None of the sludge compost piles were dug into at any time during the project.

Temperatures in 2001 Trials

The temperature response within the carcasses was an important indicator, both of the suitability of each method for achieving the pathogen reduction and of the relative performance of each of the trials.

Figure 1 shows a comparison between the internal carcass temperatures for all four trials. Note that Trial 4 (carcass on a sludge compost bed laid on the turf) had the most rapid and highest temperature response of any of the trials. It quickly reached temperatures of over 140°F(65°C) and sustained temperatures over 130°F (55°C) for several weeks. Trials 2 (carcass laid on a bed of sludge compost in a trench) and 3 (carcass laid on a bed of farm based compost on the turf) had similar temperature responses, with both exceeding 120°F (52°C) for several weeks. Trial 1 (carcass laid directly on the soil in a trench) had the lowest temperature response of all the trials. The temperatures rose slower, but eventually exceeded 110°F (47°C) and maintained that temperature for several weeks. All four trials exceeded 90°F (32°C) for at least 8 days.

Decomposition

On September 6, Piles 1 and 2 had been in place for 13 weeks; Pile 3 had been in place 12 weeks and Pile 4 had been in place 6 weeks. At that point in time, Pile 3 had achieved the greatest degree of decomposition. Most of the soft tissue was gone and the larger bones showed signs of advanced decay. The large bones were pitted on the surface and were easily broken or sliced with a knife. Pile 1, which was the carcass laid directly on the soil, also had a layer of gooey odorous material at the bottom of the pile next to the soil. Pile 4 had a similar level of decomposition to Pile 2, even though it had been in place for only 6 weeks. (Note: Pile 3, the farm based compost, was moister than the other piles and so had better conditions for composting, even though it did not have the uniform mix and higher temperature of the sludge compost.)

Evaluation of 2001 Trials

All of the trials were successful at achieving the goal of 32°c for 8 days. Given this, any of the methods tried should be suitable for containing and reducing the survival time of the FMD virus. The trials using the bed of compost (either type) placed on the turf rather than in a trench worked better than the trials in trenches from both the point of view of temperatures achieved and rate of decomposition. In addition, odors associated with the above ground piles was less than those in the trenches. This was probably due to the greater amount of air that could infiltrate the piles.

The farm based compost laid out as a bed on the soil surface and a cover of farm based compost over the carcass would be the preferred approach for managing normal mortality. The preferred approach for managing a large number of carcasses from a disease outbreak, however, would be the use of sludge based compost as in Trial 4, where the compost is laid out as a bed on the ground surface and is used as a cover over the carcass.

Other Trials – 2001 – 2003

Following the summer trials at Highmoor Farm, the Maine Compost Team conducted a winter trial using the approach that proved to be the most successful during the summer trials. One cow carcass was composted on a bed of hot municipal sludge compost with a hot compost cover. The trial ran from December 2001 to February 2002. After exactly 10 weeks the carcass was exhumed. Almost 100% of the soft tissue was eliminated and significant deterioration of the bones was observed.

Three additional trials were conducted on other farms in Maine between 2002 and 2003. The first of these occurred on a game bird farm that had an outbreak of avian influenza. Hot sludge compost was used to break down the birds and to create an environment that would kill the AI virus. A trial was conducted on a working dairy farm as a demonstration for Farm Days. This trial showed that it was possible by using dry calf bedding to achieve temperatures over 130° F for several weeks. A third trial was conducted the following winter at a small diversified farm. In this trial, the pile was started with a frozen carcass in February. It demonstrated that even under these adverse conditions, the soft tissues could be eliminated in as little as 13 weeks.

Media Comparison Trials – 2004 – 2005

The most recent trials in Maine were again at Highmoor Farm. This was a much more ambitious project that used 8 different compost media and two types of animal carcasses. This set of trials was established to serve as a basis for developing best management practices (BMPs) for Maine farmers to use in composting mortalities on their farms. Observations were made about the environmental and nuisance impacts associated with each media material as well as the performance in terms of temperatures and rate of decomposition.

The original design called for 22 individual trials. Seven different media were to be used for composting cow carcasses and four were to be used for horse carcasses. Each combination of media and carcass type was to be done twice. As the trials progressed, the design changed slightly in response to early findings and the availability of additional media materials. These changes resulted in dropping three of the original piles and adding four others. The table below indicates the combinations of media and types of carcass used.

Table 1. Combinations of Compost Media and Carcass Type Used in 2004 Trials

Media Cow Horse Foal Comment
Horse bedding X(2) X(2)
Heifer manure/bedding X(1) Only 1 trial due to lack of material
Sawdust/shavings X(2) X(2)
Woodchips X(2) Second trial included horse bedding around carcass
Municipal sludge compost X(2) X(4) 1st cow used fresh compost, 2nd used older compost
Leaf/manure mix X(2) 1st cow used fresh compost, 2nd used older compost
Silage/bedding mix X(2) 1st cow had 2/3 wet grass silage & 1/3 horse bedding; 2nd had 1/3 corn silage & 2/3 heifer bedding
Nviro Soil X(2) one used a woodchip base
Nviro Soil/Sludge Compost mix X(1)

Each trial was set up using the same methodology that proved most successful in the earlier trials. Each carcass was laid on an 18” bed of material and covered with 2 ft of material. (See photos #1 through 4.) All carcasses were vented prior to covering and had a 4 ft thermometer inserted into the abdomen to track internal temperatures. Thermometers were also placed in the compost media to read temperatures at the one foot and three foot depths. Temperatures were taken approximately 5 days per week throughout the summer, fall and early winter. Observations were also made of odors, animal activity, insect activity, leachate, pile structure changes and management activities. (A separate report details the findings associated with these observations.)

Temperature Observations 2004

Trials Temperature observations were made regarding peak temperatures achieved on all three thermometers in each pile, overall temperature profiles and number of days the internal carcass temperatures exceeded 130 °F. Compost media temperatures were also tracked for 1 and 3 ft depths in the piles.

Internal temperatures over 130° F

The most critical observation was felt to be the internal temperatures achieved in the carcasses themselves. Only seven of the 24 trials failed to achieve at least 130° F inside the carcass. For four of the seven, insufficient porosity in the media, either due to moisture or fine texture, was most likely responsible for not achieving 130° F. The other 3 all lacked energy due to a high C: N ratio or the compost mixture being too old. All of the trials that had sufficient porosity and relatively fresh materials, heated up sufficiently to achieve pathogen reduction, even in the core of the carcass. See Figure 2 for a break down of peak temperatures by media type. Seven of the trials actually achieved peak internal temperatures of over 140°F.

The duration of the high internal temperatures was also noted. Twelve of the trials maintained temperatures over 130° F for 10 days or more and eight sustained those temperatures for more than 20 days. These eight ‘top performers’ were:

Cow in fresh municipal sludge compost – 42 days

Cow in fresh leaf/chicken manure compost – 25 days

Cow in horse bedding – 34 days

Horse in fresh municipal sludge compost – 20 days

Cow in horse bedding – 40 days

Horse in fresh municipal sludge compost – 25 days

Foal in Nviro soil w/ woodchip base – 32 days

Cow in 1/3 silage, 2/3 horse bedding mix – 53 days

Figure #3 displays the results for all the trials.

Evaluation of 2004 Trials

In general, it appeared that the conditions achieved in the compost media made a bigger difference than the actual media itself. Some examples:

Municipal sludge compost performed very well in terms of both peak temperatures and duration of temperatures when it was relatively fresh i.e. had only been composting/curing for about 3 to 4 weeks. Older municipal sludge compost (over four months old) from the same facility did not have as much energy and so did not result in internal temperatures as high or for as long.

A spoiled silage/ bedding mix proved to be the best overall performer in all the trials while another spoiled silage/ bedding mix turned out to be one of the most disappointing performers. The one with the poor performance was mostly grass silage which was very wet and dense with very poor structure. Consequently, the air space collapsed out of the pile within a day or two, causing the pile to cool down and resulting in a number of other nuisance problems.

Two 400 lb. foals were buried in two piles of Nviro soil. (Nviro soil is a soil amendment made from municipal sludge, wood ash and lime.) One of these was the worst performer in terms of peak temperature achieved, only reaching about 102° F. The other was among the top eight performers, achieving temperatures of over 140° F and maintaining temperatures over 130° F for over a month. The difference was that the second carcass had a bed of woodchips underneath for better aeration.

One leaf/ chicken manure compost mix was among the poorest performers while another was among the top eight. The difference was that the first was a relatively new mix with a low C:N ratio that still had a lot of energy, while the second was several months old with a higher C: N ratio and no longer able to sustain the higher temperatures.

Conclusion

Animal carcasses can be successfully composted in a variety of media. The ability to achieve temperatures proven to kill most pathogens will depend more on the conditions in the media than on the source of the media. Those conditions that appear to be most conducive to rapid and sustained heating are:

Porosity – Piles with very fine textures or very wet materials fail to heat due to lack of oxygen. Piles with a very high porosity, such as wood chips, heat rapidly but are unable to sustain the high temperatures a long as materials with a little less air space. Textures with particles between ¼ inch and ½ inch appear to give the optimum results.

C: N ratio – As with all composting, piles with C: N ratios too high (over 40:1) tend to heat slower, in general than those with a lower C: N. One exception to this is the woodchip piles in which there is very little available carbon due to the coarse texture.

Age – Piles with materials that have been mixed and composting for several months do not have the amount of energy or activity needed to sustain the temperatures within the carcasses when compared to relatively fresh active compost piles.

BIBLIOGRAPHY

Parker, J. 1971. The Veterinary Record. Presence and Inactivation or Foot and Mouth Disease Virus in Animal Feces. June. 659-662.

Photos: 2001 Carcass Compost Trials – Highmoor Farm

Photo #1. Placing Cow Carcass on Bed of Hot Municipal sludge Compost

Photo # 2 – Covering Cow Carcass in a Trench with Hot Municipal Sludge Compost

Pile #1 – Carcass placed in trench on soil

Pile #2 – Carcass placed in trench on bed of hot compost

Pile #3 – Carcass placed on bed of farm compost (no trench)

Pile #4 – Carcass placed on bed of hot compost (no trench)

Figure 2. PEAK TEMPERATURES FOR COW & HORSE CARCASSES IN DIFFERENT MEDIA

2004 Trials

Figure 3. NUMBER OF DAYS OVER 130° F in COW & HORSE CARCASSES IN DIFFERENT MEDIA

2004 Trials

Photos: 2004 Carcass Compost Trials – Highmoor Farm

Photo #3. Ventilation of Cow Carcass on Horse Bedding Base

Photo # 4 – Covering Cow Carcass with Silage/bedding Mix.

New York State’s Implementation of Mortality Composting

Jean Bonhotal

Cornell Waste Management Institute

Dept. of Crop and Soil Sciences

101b Rice Hall

Ithaca, NY 14853

607/255-8444 (w), jb29@cornell.edu

On-Farm Mortality — Current Situation

Until recently rendering plants have offered prompt, reasonably priced pickup of dead livestock at the farm. However, recent declines in prices of hides, tallow, meat and bone meal and the other useful commodities produced from animal carcasses have curtailed many rendering operations. In 2002, remaining plants are charging up to $70 for cows, $60 for pigs and $200 per horse to pickup animal carcasses from farms in their area. As a result, many livestock farms no longer have affordable access to rendering service.

Many livestock producers are unsure of what they should or could be doing to properly dispose of the occasional animal carcass. Brief anonymous surveys conducted in western New York and northern Pennsylvania reveal a widespread practice of improper mortality disposal. Animal carcasses left to decay naturally above ground or buried in shallow pits pose risks to surface and groundwater and endanger the health of domestic livestock, wildlife and pets. Likewise, land spreading of farm hospital pen wastes and fetal membranes may have implications for the biosecurity of the herd.

In the year 2001, there were 670,000 milk cows and 80,000 beef cows in New York State (Source: NYS Agriculture Statistic Service, www.nass.usda.gov/ny). With a typical death loss in dairy herds of two percent each year and beef herds of one-half percent per year, and a disposal cost of $30-70 per head, the state’s livestock producers could save over half a million dollars with an easily managed, low cost mortality disposal alternative.

Response

Cornell Waste Management Institute has developed a 20 minute video, “Natural Rendering: Composting Livestock Mortality & Butcher Waste” and 10 page fact sheet and posters that are used to help teach farmers and butchers to implement these practices. Additional materials will be produced to address road kill.

Demand from farmers and butchers combined with CWMI expertise in the compost field made this program a natural fit. To date demonstration sites in 22 counties (serving 38 counties) have been set up with over 10,000 people in NY, VT and PA attending workshops 2001-05. Workshops generally consisted of presentation and pile openings in a 3-hour workshop. As workshops were set up hosts tried to ensure the local educators/ regulators were invited including NYS Dept of Environmental Conservation, Health Dept, NRCS, veterinarians, Cornell Cooperative Extension Agents and agriculture educators so they could enhance relationships and better understand the process.

Through workshops, tours and events CCE agents and others were trained to carry out local programs with technical support from CWMI. Display and demonstrations were utilized at trade shows like Empire Farm Days, fairs and conferences to raise the awareness of thousands of attendees. Newsletter, newspaper, and magazine articles will reach 16,500 producers throughout the Northeast Region. Cornell Waste Management Institute has posted the fact sheet and linked to other sites such as the Pro-Dairy web site. The “Natural Rendering”, program has received national awards from American Society of Agriculture Engineers, state and national agriculture associations and Outstanding New Extension Publication Award.

Impacts on Policy and Guidance

When composting mortality and butcher waste the process reduces odor, volume and pathogen. This is helping farms with their bio-security and has become part of CAFO plans. Research is currently on going for pathogen and use of the end product.

  • NYSDEC promotes composting of mortality including road kill. They have a general mortality composting guidance in draft and they have released a report promoting road kill composting. New regulations will reflect these recent developments.
  • NRCS has revised their national mortality standard. We also worked with NYS NRCS to revise (provide more detail) the compost and mortality standards to better suit NYS needs.
  • NYS DOT Region 8 has written a guidance document to help their regions implement mortality composting.

Static Pile Composting Method for Mortality

Consider Composting

The livestock and custom butcher industries need a convenient, socially and environmentally acceptable, biosecure way of disposing carcasses and butchering residuals. Landfills generally will not accept residuals or carcasses. The livestock farmer and custom butcher find themselves, in many cases, without disposal services or facing high disposal fees. Most people don’t realize that composting is a legal and acceptable way of disposing these materials. They fear that if regulators find out, they may be cited and fined. Regulators, on the other hand, fear that with the current disposal situation, farmers and butchers may cause serious problems with improper disposal. Composting can be accomplished in compliance with environmental regulations in many states, but check regulations before you start.

Composting provides an inexpensive alternative for disposal of all dead animals, butcher wastes and other biological residuals. The temperatures achieved during composting will kill or greatly reduce most pathogens, reducing the chance to spread disease. Properly composted material is environmentally safe and a valuable soil amendment for growing certain crops.

Composting animal carcasses is not new. Chickens, pigs, calves and occasional larger animals are composted. Ohio, Utah and Maryland have written resources and Maryland has a video on chicken carcass composting. Little information, however, is available to guide farmers that want to compost adult cattle or butcher residuals.

Composting

Static pile composting of dead, intact, fully-grown livestock and calves, aborted fetuses, placental membranes and butcher residuals is a practice that can fit into the management of livestock farms and butcher operations. The practice does require space on your land to construct the compost piles and takes from two to six months for the animal to decompose. Composting provides an inexpensive alternative for disposal of animal-based wastes.

Lowest Risk

  • Picked up by rendering company within 48 hours after death or properly composted on the farm.
  • Buried 6-ft deep in appropriate soils and buried more than 200 feet from a water body, watercourse, well or spring.
  • Partially buried less than 6-ft deep or buried closer than 200 feet from a water body, watercourse, well or spring.

Highest Risk

  • Carcass is left outside for scavengers or to decay. Because of the cost of disposal, it will be tempting to dispose of carcasses by leaving them exposed in a woodlot to be scavenged. This is very risky from an environmental standpoint and that of disease transmission on your farm.

Caution

Animals showing signs of a neurological disease must be reported to authorities and disposed of in the manner they recommend. It is not clear whether prions, the agent that causes Bovine Spongiform Encephalitis (Mad Cow Disease), would be destroyed in the composting process. Animals that show signs of a neurological disease should not be composted. Animals under quarantine that die and those with anthrax, should not be composted.

Key Points of Static Pile Carcass Composting

  • Select site that is well drained, at least 200 feet from water courses, sinkholes, seasonal seeps or other landscape features that indicate the area is hydrologically sensitive.
  • Lay 24-inch bed of bulky, absorbent organic material containing sizeable pieces 4-6 inches long. Utility and municipal wood chips work well. Ensure the base is large enough to allow for 2-foot clearance around the carcass.
  • Lay animal in the center of the bed. Lance the rumen to avoid bloating and possible explosion. Explosive release of gases can result in odor problems and it will blow the cover material off the composting carcass.
  • Cover carcass with dry, high-carbon material, old silage, sawdust or dry stall bedding (some semi-solid manure will expedite the process).
  • For young animals, layer mortalities with a minimum of 2 feet of carbon material between layers.
  • Let sit for 4-6 months, then check to see if carcass is fully degraded.
  • Reuse the composted material for another carcass compost pile, or remove large bones and land apply (see Use of Finished Product and Bones section). Site cleanliness is the most important aspect of composting; it deters scavengers, and helps control odors and keeps good neighbor relations.

Turning Note

Carcass and butcher residual piles should not be turned early in the process unless there are no neighbors that would be affected. Odor is a big issue most of the time. After 3 months, turning is an option and will speed the curing process.

Monitoring Compost Piles or Windrows

A log of temperature, odor, vectors (any unwanted animals), leachate (liquid that comes out of the pile), spills and other unexpected events should be kept as a record of the process. This will allow the composter to see if sufficiently high temperatures were reached and adjust the process if there is any problem. Also, odor can be an issue and compost piles are an easy target for complaints. When there is an odor problem, a compost pile may be blamed and may not be the cause.

Monitoring of the pile is done mostly by checking temperatures. Internal compost pile temperatures affect the rate of decomposition as well as the destruction of pathogenic bacteria, fungi and some seeds. The most efficient temperature range for composting is between 104ºF and 140ºF (40ºC and 60ºC). Compost pile temperatures depend on how much of the heat produced by the microorganisms is lost through aeration or surface cooling. During periods of extremely cold weather, piles may need to be larger than usual to minimize surface cooling. As decomposition slows, temperatures will gradually drop and remain within a few degrees of ambient air temperature. Temperature monitoring is crucial for managing the compost process. Thermometers with a 3-4 foot probe are available (see Thermometer Sources).

Pathogen Control

Pathogens are organisms that have the potential to cause disease. There is a wide array of pathogens found in our environment and pathogens may be elevated in compost operations. While there are currently no temperature regulations for mortality and butcher residual composting, following NYS DEC regulations currently applicable for biosolids is highly recommended to ensure adequate pathogen control and minimization in this type of composting.

If using an aerated static pile, the pile must be insulated (covered with a layer of bulking material or finished compost) and a temperature of not less than 131ºF (55ºC) must be maintained throughout the pile for at least 3 consecutive days, monitored 6-8 inches from the top of the pile.

Very little work has been done on documenting pathogen kill in composting of dead animals and butcher residual. Research at Ohio State University suggests that common bacterial and viral pathogens are killed in regularly turned compost piles containing carcasses. Static-pile composting is being recommended as a more easily managed mortality composting technique. By properly constructing the compost pile to allow for adequate natural aeration, mortality composting can be completed on intact animals without physically turning and mechanically aerating the pile. Degree and duration of temperatures achieved in static-pile composting are adequate to significantly reduce pathogen survival. Compost amendment variables, temperature and pathogen kill in static compost piles are currently being investigated.

Use of Finished Product and Bones

It is recommended to reuse finished compost as the base for the next pile. The remaining bones add structure to the base material for improved aeration. The composted material can also be used on hay, corn, winter wheat, tree plantations and forestland. Applying this compost to “table-top” crops directly consumed by people is not recommended at this time. In the future, testing and quality assurance standards may enable expanded uses or sale of the finished compost product. Nutrients in carcass and butcher residue composts are higher in N, P and K than compost containing only plant material, giving it more fertilizer value on and off farms.

When animal carcasses or butcher waste is composted, the large bones do not completely break down. Bones from immature animals degrade very quickly, but bones from mature animals take several seasons to breakdown. After the material is composted, bones can be reused as part of the base for the next compost pile. The bones that did not completely break down will add structure to the pile. Bones can be buried or disposed of in bone piles. Animal in the wild eat bones to meet calcium requirements.

When spreading the composted material, the bones can be removed and put in a hedgerow or forested land. Because they contain phosphorus and calcium, rodents will eat them; the smaller bones can be land spread and will disappear quickly. Smaller bones can be land spread, but large bones may splinter and can puncture tires. Also, avoid leaving skulls in the fields. Neighbors and the passing public may not fully understand the sight of a skull in the fields!

Economics of Mortality Disposal

Options

Pick-up

Where available, the fee for pickup of dead animals ranges from $25-70/cow, $60/pig, and $200/horse. Some species are not accepted at all in rendering.

Burying

A Pennsylvania survey reports backhoe and loader rentals cost approximately $43.50 per hour. If we use one hour of labor at $10.00 per hour and about 0.6 gallons of fuel at $1.50 per gallon, the total cost for burial of a large carcass would be $54.40. Though carcass burial is permitted in New York, some states have outlawed the practice citing potential groundwater contamination. Burial at the recommended depth is also impractical in areas of shallow bedrock and when soils are deeply frozen.

Composting

The amount of carbon material (i.e., wood chips, sawdust, etc.) required to compost a full-grown cow is 12 cubic yards. Many of these materials can be used more than one time. Example: incorporating the residual bones and chips into the next season’s base material.

Presently, wood mulch is selling at about $550 per tractor trailer load, or $5.50 per cubic yard. The cost per carcass for the five cubic yard base would be $33. If we assume reuse of the composted material from other piles and a 30% loss of material during composting, the cost for the base would be $9.90 per carcass. The remainder would be used as cover on a new base of wood chips and mulch. Kiln-dried sawdust is selling for $550 per load, or $4.50 per cubic yard. If we used six cubic yards the cost would be $27. With a 30% loss of material during the process, the cost per carcass would be $8.10. The total cost of material per carcass would be $18.

If we estimate 30 minutes for preparation and covering, the cost for labor would be $5; fuel for a 100 hp tractor at 0.4 gallons or $0.60. Tractor and loader rental in the northeast as reported by Doanes is $28 per hour. The total cost for the material, equipment, fuel and labor would be $37.60 per large carcass.

As you can see, the cost of death is expensive in more ways than one.

Source: Bonhotal, J.F., Telega, S.L., and Petzen, J.S. 2002. Natural Rendering: Composting Livestock Mortality & Butcher Waste, Cornell Waste Management Institute, 12 page fact sheet and 3 posters. For the complete fact sheet and further information visit http://cwmi.css.cornell.edu

Observations of Static Pile Composting of Large Animal Carcasses Using Different Media

Submitted by: Mark A. King, Maine Department of Environmental Protection, 17 State House Station, Augusta, Maine, 04333, Mark.A.King@Maine.gov

Authors: M. A. King, B. Seekins, M.L. Hutchinson

Introduction:

During the summer of 2004, the Maine Compost Team, a collaborative interagency team including members from the Maine Department of Environmental Protection, Maine Department of Agriculture, and University of Maine Cooperative Extension, began a study to determine if large animal carcasses (bovine and equine) could be properly composted using a host of residuals that are commonly found on-farm and at various solid waste processing facilities.

We chose to conduct our trials at Highmoor Farm, a University of Maine owned agricultural research center located in Monmouth, Maine. Highmoor Farm operates as a “working” farm, focusing on fruit and vegetable production.

The entire site consists of 250 acres of hay fields, interspersed with various garden trials and apple orchard plots. Our study site consisted of an eight (8) acre parcel of hay field underlain by moderately well-drained soils with 0-8% slopes. The entire study area was surrounded by a dense mixture of hardwood and coniferous trees (Figure 1). This combination, soils with the ability to properly treat leachate losses and excellent visual-screening afforded by the tree buffer, gave us an opportunity to conduct our trials in a real-life situation.

Aerial views of Highmoor Farm agricultural research center.

Study Design:

A total of eight (8) separate trials, with up to four (4) variants each (two (2) horse carcasses and two (2) cow carcasses) were set up and allowed to run for a two to three month “active compost” period, without turning or disturbance. Compost piles were formed using a farm tractor and combinations of the following residuals (exact trial recipes are listed in Table 1, below): horse manure, poultry manure, leaves, sawdust shavings, wood chips, animal bedding, N-Viro© Soil, and, hot, immature municipal sludge compost. Once the pile base was formed with 18-24 inches of compost media, the carcass was added and then covered with an additional 24 to 36 inches of mixture.

Prior to final covering, the carcass abdomen was vented, in numerous areas, using a six-foot-long piece of re-bar. A four-foot thermometer was inserted into the abdomen to allow carcass temperature monitoring. Finally, the carcass was covered and two more thermometers were added to the pile at one foot and three foot depths.

Table 1. Compost Trial Mixture Recipes
Trial Pile Composition Density (lbs./yd3) C:N
C1A Horse Bedding 450 62
C1B Horse Bedding 450 62
C2B Cow Manure (wet) + Horse Bedding 750 21
C3A Wood Shavings 250 578
C3B Wood Shavings 250 578
C4A Wood Chips 250 677
C4B Wood Chips + Horse Bedding (core)
C5A Sludge Compost (3 weeks old) 550 28
C5B Sludge Compost (3 months old)
C6A Hen Manure +Leaves 550 16
C6B Hen Manure/Leaves 300 52
C7A 2/3 Silage + 1/3 Horse Bedding 700 18
C7B 1/3 Silage + 2/3 Horse Bedding 550 17
C8A Sludge Compost + N-Viro© Soil 800 30
H1A Horse Bedding 450 62
H1B Horse Bedding 450 62
H3A Wood Shavings 250 578
H3B Wood Shavings 250 578
H5A Sludge Compost (3 weeks old) 550 28
H5B Sludge Compost (3 months old)

Note: A “C” prefix in the trial column indicates a cow carcass trial and an “H” indicates a horse trial.

Each completed pile was sampled and tested for: bulk density (lbs. /yd3), Carbon to Nitrogen Ratio (C: N), and pile nutrients (N, P, K and Total C). Additionally, overall mixture quality was observed, focusing on pile texture and relative porosity. During the “active” compost period, temperatures were taken, on a daily basis, from the three points within each pile: one foot deep, three feet deep and within the core of the carcass itself. Finally, pile observations were made

regarding odor generation, animal (vector) scavenging activity/disturbance, and leachate generation. A field monitoring system (thermometer and rain gauge) was set up to provide data on ambient temperatures and precipitation volumes. This paper focuses on field observations noted during the course of the compost trials, including: pathogen reduction performance, odor generation, animal (vector) activity, and leachate generation.

Study Results:

Pathogen Reduction Performance

All but four (4) of the compost trials (N = 20) met or exceeded the EPA time and temperature standards for pathogen reduction (three consecutive days at 130° F). The trials using horse bedding (C1A, C1B, and H1B), municipal sludge compost (C5A, C5B, H5A, and H5B), one mixture combining 1/3 silage and 2/3 horse bedding (C7B), and one mixture using hen manure mixed with municipal leaves (C6A), performed exceptionally well, sustaining temperatures in excess of 130° F for greater than 17 consecutive days (range 17-53 days). Trial H1A (equine carcass in horse bedding) was the first study pile constructed, and consisted of a large draft horse. Although this pile never reached the pathogen reduction goal, it is important to note that it did manage to sustain 128° F for most of the active compost period. The trials using wood shavings (C3A, C3B, and H3A) had moderate success (averaging greater than eight consecutive days above 130° F). The remainder of the piles failed to reach target temperatures for a variety of reasons explained below.

Pile C2B (adult Holstein in 50% cow manure + 50% horse bedding) reached a maximum temperature of 116° F. This mixture had a very high bulk density (750 lbs. /yd3) which made it difficult to achieve a homogenous blend using the farm tractor bucket. As a result, this pile performed poorly due to inadequate porosity and texture, although it had a near optimal C: N ratio of 21.

Pile C6B (adult Holstein in 50% poultry manure + 50% municipal leaves) reached a high of 114° F. This pile, like C2B, was difficult to mix thoroughly (bulk density 300 lbs. /yd3), even though a manure spreader was used to enhance the mixing process. Additionally, C6B suffered due to the relative lack of “energy” afforded by the leaves and manure mixture. The municipal leaves had been stored on-site for several years, and were fairly decomposed when added to the manure, which was also about two months old. The combined mixture had a fairly high C: N of 52.

Pile H3B (adult horse in 100% wood shavings) reached a high of 111° F. This pile was formed in early August and never seemed to take-off. The final mixture had a bulk density of 250 lbs. /yd3 and a C: N ratio of 578. Although the texture and porosity allowed for ample aeration, the carcass did not provide enough nitrogen to “fuel” the compost process and overcome the high C: N ratio. Additionally, this pile was susceptible to cooling from heavy winds and drenching rain.

Pile C8A (50% N-Viro© Soil + 50% municipal sludge (three months old) achieved a peak temperature of 103° F. This mixture had a “high” bulk density (800 lbs. /yd3), a very fine texture, and poor porosity. This combination greatly inhibited self-aeration of the pile during active composting. Additionally, the relative high pH of the N-Viro© Soil (pH = 10-11) also served to inhibit microbial activity, resulting in a poor temperature response.

Odor Generation and Vector Attraction

Six of the compost trials (N = 20) experienced numerous odor releases (# >2) and animal disturbances (# > 2) during our study. This was especially true for the trials using recipes comprised entirely of wood chips or wood shavings. Additionally, the site was frequented by scavenging animals (vectors) due to a local farm dump, consisting of waste fruits and vegetables, located adjacent to our study area. The odorous piles proved to be very attractive to vectors, resulting in the need for diligent site management (Figure 2).

animal disturbance in compost pile

Pile C4A and C4B (adult Holsteins in wood chips) had the highest incidences of odor releases and animal disturbances (14 odor incidents and four (4) animal disturbances for C4A, and four (4) odor incidents and 5 animal disturbances for C4B). Both of these trials had a very low bulk densities (250 lbs. /yd3) and very coarse texture that self-aerated easily. These mixtures also had the highest C: N ratios recorded during the study (677) and very little fine textured material available to capture soluble nutrients or to provide energy for microbial activity. As a result, as the carcasses decomposed, anaerobic (odorous) gases escaped the pile unabated and proved to be irresistible to vectors. Additionally, flies and maggots were observed on numerous occasions on the surface of these piles. Our belief is that the lack of aerobically driven microbial activity in the pile, coupled with the lack of fine carbon particles (to help absorb leachate) and resultant low temperatures in the media surrounding the carcass provided an optimal environment for the maggots, allowing them to travel back and forth between the carcass and the pile surface without consequence.

Pile H1A (adult horse in horse bedding) and H3A (adult horse in wood shavings) also had numerous odor releases and animal disturbances (three (3) odor releases and five (5) animal disturbances for H1A, and six (6) odor releases and four (4) animal disturbances for H3A). Like the wood chip trials, both of these piles had relatively low bulk densities (H1A = 450 lbs. /yd3; H3A = 250 lbs. /yd3) and excellent porosity. Trial H1A, as previously noted, was the first pile constructed as part of this study. Because of the large size of the horse (lengthwise), the pile was constructed in a long rectangular shape. Initially, we believe that we had applied sufficient cover, but later found that as the animal decomposed and shifted, there was not enough cover material to maintain pile structure. Another confounding factor was venting of the animal. This carcass was punctured once in the abdomen to release trapped gasses. This proved to be insufficient, as the carcass continued to expand and contract as it released trapped gasses; resulting in further compromise of pile structure. As a result of the odor releases and lack of proper cover material, this pile was continually disturbed during the first couple weeks necessitating numerous rakings and additions of horse bedding. We finally decided to add a thicker coating of horse bedding, place snow fencing over the pile surface, and erect a snow fence around the entire pile as a “biosecurity” measure. Additionally, a scarecrow (with visual and auditory distracters) was added to help discourage on-site animal activity (Figure 3). These collective acts resulted in elimination of the vector problem.

scarecrow

Pile H3A experienced a somewhat different vector issue. This pile was formed in late August and almost immediately maggots were noted at the top of the pile surface. In fact, the maggots became so populous that the top of the pile literally appeared to be moving. Not long after the maggots appeared, the study site became populated with 10 to 20 wild turkeys. The turkeys, initially attracted by the adjacent dump site and an on-site hen manure stockpile, began feeding on the maggot-infested pile. Turkeys are notorious for tearing apart the ground as they forage. Pile H3A was no exception. Large portions of the pile face were torn away as the turkeys foraged for maggots (see Figure 2, above). Turkeys continued to disrupt the piles even after numerous re-coverings of the compost pile with horse bedding, and application of hot sludge compost to kill back the maggots. Therefore, we finally decided to obtain an “Animal Nuisance Control” permit from the Maine Department of Inland Fisheries and Wildlife to help discourage turkey scavenging at the study site.

The remainder of the piles had infrequent odor releases and incidental animal disturbances (animal tracks on pile surface or slight exploratory digging events). For most of these piles, surface raking and additional amendment placed over the chimney area (upper top of pile) was sufficient to suppress additional odor events and to discourage animal disturbances.

Leachate Occurrences

The final area of observation involved incidents of leachate generation following precipitation events. As with other factors, leachate incidents were most prevalent for the piles constructed entirely of wood chips (C4A, six (6) occurrences and C4B, eight (8) occurrences). Both of these piles exhibited pools of leachate at the base following rain events in excess of one inch. The leachate was usually pink to dark red during the first part of the active compost phase and brown to dark brown near the very end of the compost phase. The low bulk density and coarse pile structure (very few fines) of these piles, allowed precipitation to percolate down through; flushing nutrients as it exited. This continual loss of nutrients is of concern as it affects the overall quality of the finished product, as well as raising the potential for dissolved nutrients to leach to groundwater and/or enter nearby surface waters. Based on these observations, along with the odor and vector issues noted previously, we decided not to conduct additional wood chip trials using horse carcasses. The remainder of the piles experienced fewer than two (2) leachate episodes during the course of the study, and only following precipitation events in excess of two (2) inches.

Recommendations:

The observations from this study indicate that on-site management is crucial throughout the composting event, especially during the first two weeks. Good site and carcass preparation facilitate carcass decomposition without causing nuisance odors, vector attraction issues, or generation of nutrient-rich leachate. Piles should be constructed using compost mixes with moderate bulk densities (300-550 lbs./yd.3), optimal C: N ratios (25 to 40), good texture (appropriate mix of fine and coarse particles) and optimal porosity and pile structure. Horse bedding and municipal sludge compost performed very well during our trials and are ideal for most carcass disposal situations. Carcasses must be vented in numerous locations to release trapped gasses and allow abdominal contents an opportunity to mix with compost ingredients. In many cases, carcass legs may be tied together, depending on state of “rigor mortis”, to help prevent extension out of pile as the carcass expands. Carcasses should be covered with 24 to 36 inches of cover material. This should be monitored during the first two weeks of composting, as carcasses slump, causing pile structure to collapse. Additional amendment may be needed, especially following pile collapse. Any occurrences of odors or maggots must be addressed before scavenging animals arrive. Covering with an appropriate amount of amendment will aid in reducing odor. Covering piles with hot, active compost will deter maggots. Likewise, leachate pools may also be amended and then re-incorporated into the compost piles.

In-House Composting of Turkey Mortalities as a Rapid Response to Catastrophic Losses

Eric S. Bendfeldt4, Robert W. Peer5, Gary A. Flory6, Greg K. Evanylo7, and George W. Malone8

4 Extension Agent, Environmental Sciences, Virginia Cooperative Extension, 965 Pleasant Valley Road, Harrisonburg, Virginia 22801-0963 Phone: (540) 564-3080 Fax: (540) 564-3093 Email: ebendfel@vt.edu

5 Agricultural Program Coordinator, Virginia Department of Environmental Quality, Valley Regional Office, P.O. Box 3000, Harrisonburg, Virginia 22801 Phone: (540) 574-7866 Fax: (540) 574-7844 Email:

rwpeer@deq.virginia.gov

6 Agricultural and Water Quality Assessment Manager, Virginia Department of Environmental Quality, Valley Regional Office, P.O. Box 3000, Harrisonburg, Virginia 22801 Phone: (540) 574-7866 Fax: (540) 574-7844 Email: gaflory@deq.virginia.gov

7 Extension Specialist, Department of Crop and Soil Environmental Sciences, Virginia Tech, 426 Smyth Hall (0403), Blacksburg, Virginia 24061 Phone: (540) 231-9739 Fax: (540) 231-3075 Email: gevanylo@vt.edu

8 Extension Poultry Specialist, University of Delaware, 16684 County Seat Hwy., Georgetown, Delaware 19947 Phone: (302) 856-2585 Fax: (302) 856-1845 Email: malone@udel.edu

An avian influenza (AI) outbreak in the central Shenandoah Valley of Virginia in the spring and summer of 2002 affected 197 poultry farms and had an estimated cost of $130 million to the poultry farmers and state economy. The total federal cost of avian influenza eradication in Virginia, including indemnity, was $81 million (Akey 2003; Swayne and Akey, 2004). Seventy-nine percent of the farms depopulated were turkey breeder and growout flocks. Five different methods were used to dispose of avian influenza infected poultry: on-farm burial, landfilling, incineration, slaughter, and composting (Ag-Bag and in-house). More than 3.1 of the 4.7 million birds infected or 13,000 tons were disposed of in landfills (DEQ 2002). Landfilling has been the preferred option for disposal because the infected flock can be removed from the poultry farm relatively quickly, which enables the farmer to begin cleaning and disinfecting the poultry houses. Drawbacks of landfilling include expense, transportation logistics, biosecurity risks, public perception issues, and environmental considerations. In 2002, turkey disposal costs exceeded $7.25 million with an average cost per farm of $30,175. The cost per ton with depopulation and disposal approached $145 not including the costs of additional litter handling at the farm.

Avian influenza depopulated poultry houses remained under quarantine on an average of 75 days each and for as long as 177 days (DEQ 2002). Composting was implemented as a disposal technology for two flocks during the outbreak with limited supervision and success. In-house composting has not been considered a viable option by the industry because of the potential loss of production space and the perception that composting would not work on larger birds. Successful in-house composting of 5-pound broilers on the Delmarva Peninsula in 2004 proved

the effectiveness of composting as a method of disposal and containment for an AI outbreak (Malone, 2004a; Malone et al., 2004b). Avian influenza was confined to 3 farms despite the high density of poultry farms in the area. In-house composting appears to be the most acceptable method of disposal because it limits the risks of groundwater and air pollution, high fuel costs, potential for farm-to-farm disease transmission, transportation costs, and tipping fees (Tablante et al., 2002).

The project objectives were:

  • To test in-house composting as a method of disposal and disease containment for large birds (i.e., 17 to 40 pounds);
  • To determine how quickly the in-house process could be completed;
  • To test the effectiveness of carbon sources and rates;
  • To compare the effectiveness of composting whole carcasses, shredded and tilled carcasses, and crushed carcasses;
  • To demonstrate the composting process for farmers, industry and agency personnel.

The demonstration was initiated on December 2, 2004. Eight windrows (12’ wide by 6’ high), each representing a treatment, were formed. Each windrow contained 2500 to 3000 pounds of turkey carcasses weighing from 17 to 40 pounds each. An additional experiment was conducted to compare the effectiveness of crushing the carcasses versus whole birds and to determine the minimum amount of carbon material needed to prevent leakage and encourage composting at the highest possible density per square foot. The temperatures of all the windrows (i.e., at 10 and 30 inch depths) reached between 135 and 145 degrees F and maintained temperatures adequate for pathogen kill. The windrow with woodchips as the carbon source achieved the highest temperatures (Figure 1).

Carbon materials compared for their effectiveness in composting turkey carcasses included:

  • Hardwood Sawdust;
  • Aged, weathered woodchips with relatively high moisture;
  • Built-up Litter;
  • Starter litter or wood shavings from brooder house;
  • Blend of starter litter and built-up litter.

The turkey carcass treatments included:

  • Whole carcasses mixed and piled;
  • Shredded and tilled carcasses, mixed and piled;
  • Crushed carcasses mixed and piled.

The results of the research and demonstration are summarized as follows:

  • After two weeks, few carcasses remained in any of the windrow treatments.
  • All four carbon materials (i.e., hardwood sawdust, woodchips, built-up litter, and starter litter) were effective in composting the turkey mortalities.
  • Temperatures of all the windrows (at 10 and 30 inch depths) reached 140 degrees and maintained temperatures adequate for pathogen kill.
  • Woodchips reached and maintained the highest temperatures due to good porosity, varying particle size, and relatively ideal moisture content.
  • The starter litter required that some water be added during the mixing process, but only enough to make the litter and mixture glisten.
  • Shredding and tilling the carcasses increased the effectiveness of composting approximately 2 to 3 days by increasing the surface area to volume ratio and exposing the bones and marrow to further decomposition and releasing more moisture into the compost mix.
  • Whole carcasses composted as well without tilling.
  • Tilling the litter floor after depopulation to break up excessive caked or crusted litter helped to increase the composting process and prevent any seepage.
  • Maintaining the base and cap on the windrow is essential to composting and preventing any carcasses from being exposed to the air which can prevent decomposition.
  • An alternative to tilling and shredding the birds would be to crush the birds by running them over with a skid loader or tractor.

To determine the minimum amount of carbon material needed, an additional experiment was setup to simulate the worst case scenario (i.e., where a farmer had very little litter or carbon material available following a clean-out and was attempting to compost heavy toms (~ 35 to 40 pounds)). The treatments compared were crushed carcasses versus whole carcasses. These were mixed with a blend of starter and built-up litter to achieve a density 12.5 pounds of carcass per square foot (Table 1) above a 5 inch base layer and below a 5 inch cap.

Table 2. Average characteristics of different turkey types and population densities.*

Bird Type Age (weeks) Weight (lbs.) % Mortality Population(after mortality) Size of House (ft2) # of meat/ft2
Brooder hens 5 3.5 3 11,058 10,000 3.87
Brooder toms 5 4.0 4 8,640 10,000 3.46
Growout hens 14 17.5 2 10,837 20,000 9.48
Heavy hens 16 22 2 10,837 20,000 11.92
Light toms 15 24 8 7,949 20,000 9.54
Heavy toms 20 40 8 6,250 20,000 12.50

* The production goals and requirements for individual farms may vary from these averages.

The results from the experiment to determine the minimum carbon material needed for composting heavy toms are summarized as follows:

  • Temperatures of 140+ degrees were achieved within 5 days for the crushed treatment and 16 days for the whole carcass treatment (Figure 2). Therefore, the poultry house could potentially become available 11 days sooner if the carcasses are initially crushed.
  • With a 5 inch base layer and 5 inch cap (10” total), no seepage occurred at a density of 12.5 pounds per square foot and composting was promoted.
  • Without crushing the carcasses, the whole birds tended to roll off the pile, require more labor, and take longer to begin composting.
  • In the whole carcasses treatment, at least 0.8” of carbon material per pound of carcass was needed as a base and cap to adequately cover the carcass. More material, approximately 1” of carbon material per pound of carcass, was needed to promote composting.
  • In the worst case scenario, where there is very little base litter (i.e., < 5”) and heavy toms in the poultry house, two tractor trailer loads of additional carbon material may be needed per house to promote composting. (In 2002, seven tractor trailer trucks were needed per house to haul carcasses off the farm to the landfill.)

A typical turkey farm affected with avian influenza in 2002 was as follows:

  • 45,600 turkeys
    • 22,800 – 14 week old hens, Avg. body Wt. 16 lbs.
    • 22,800 – 4 week old hens, Avg. body Wt. 3 lbs.
  • 352,000 pounds + 66,000 pounds = 418,000 pounds or 209 tons
  • 14 Semi truck loads.

Cost estimates for in-house composting after euthanasia and depopulation:

  • 2 skid loaders ~ $140 per house;
  • 2 skid loader operators ~ $180 per house;
  • 1 person knowledgeable of composting ~ $150 per house;
  • 2 laborers ~ $120 per house for cleaning up litter and disinfecting skid loaders;
  • 5 to 6 hours of operation per house including crushing the carcasses.
  • 1 hour to clean and disinfect the skid loaders.

Cost estimates if no additional carbon is needed to compost the turkey carcasses:

  • ~ $590 per house/ 104.5 tons of carcass per house = $5.65 per ton (if no additional carbon material is needed).
  • ~ $700 for one 200’ roll of reusable compost fleece per house if a litter storage shed is not available.

Cost estimates if additional carbon is needed to compost the turkey carcasses:

  • ~ $1000 per house for hardwood sawdust.
  • ~ $590 per house for labor and equipment.
  • 104.5 tons of carcasses per house.
  • $15.22 per ton (if additional carbon material is needed).
  • ~ $700 for one 200’ roll of reusable compost fleece per house.

Additional considerations for utilizing in-house composting as a disposal and disease containment method are summarized as follows:•

  • Farmers and industry have expressed concern about the quality of the finished product and the presence of bones. In the research with heavy toms, only the upper part of the leg bones was visible. Other bones broke down during the compost process.
  • Application of the final compost to tillable row crops like corn, small grains, and soybeans would be the preferred method of utilization.
  • Applications to pasture or hay land would require a simple method of screening the bones such as through a box spreader.
  • In 2002, moving the untreated litter from AI infected farms was a problem and stigma. An incentive payment of $10.00/ton of litter was needed and implemented to facilitate movement of 5000 tons of litter off farms.
  • In-house composting could resolve some of these issues because composting reduces the volume of litter 40 to 60%, provides sufficient heat to deactivate most pathogens, and produces a quality final product that would not require an incentive payment to facilitate movement of the litter off farms.

Action items and potential research needed to make in-house composting the preferred option for disposal in a disease outbreak and catastrophic loss:

  1. Identify suitable compost sites on individual farms for final composting and curing;
  2. Identify and research which types of farms (i.e., broiler breeder, turkey breeder, double-deck houses) may need to compost outside of the house after euthanasia and depopulation;
  3. Evaluate biosecurity and farm-to-farm transmission concerns prior to bird and litter movement;
  4. Identify and secure several sources of carbon material (e.g., sawdust and woodchips) before an outbreak occurs. Sources might include county landfills, lumber mills, electrical power companies, tree trimming companies, and compost from wastewater treatment facilities.
  5. Negotiate a long term contract for at least enough carbon material to compost five average size farms in an outbreak (i.e., about 10 tractor trailer loads@100 cy./load).
  6. Encourage integrators to identify a site to stockpile carbon materials such as a county landfill or one of their facilities. 7) Request each integrator to designate a team or person to be trained for managing in-house composting in an outbreak and catastrophic loss.

In-house composting is an acceptable cost-effective method of disposal and disease containment. In-house composting has not been considered a viable option by the industry and farmers because of the potential loss of production space and the perception that composting would not work on turkeys. In-house composting of turkeys demonstrates that with a good base, cap, and proper disease monitoring, the compost could be turned and moved out of the poultry house within 3 to 4 weeks. This time would be comparable to the minimum down time experienced by farmers in the 2002 avian influenza outbreak. Each farm and type of flock would have to be evaluated, but with proper planning and training of farmers and industry personnel, in-house composting is an effective rapid response tool for managing catastrophic poultry losses.

References

Akey, B.L. 2003. Low-Pathogenecity H7N2 Avian Influenza Outbreak in Virginia during 2002. Avian Diseases 47:1099-1103.

Malone, G. 2004. In-house composting of avian influenza infected flocks. Proceedings 2004 Virginia Poultry Health & Management Seminar. Roanoke, VA. pp. 23-24.

Malone, G., S. Cloud, R. Alphin, L. Carr and N. Tablante. 2004. Delmarva in-house carcass composting experiences. Proceedings 2004 National Meeting on Poultry Health and Processing. Ocean City, MD. pp. 27-29.

Swayne, D.E., and B.L. Akey, 2004. Avian influenza control strategies in the United States of America. pp. 113-130. In: G. Koch (ed.) Proc. of the Wageningen Frontis International Workshop on Avian Influenza Prevention and Control. Wageningen. The Netherlands: Kluwer Academic Publishers. (Available on-line at http://library.wur.nl/frontis/avian_influenza/13_swayne.pdf.) (Verified 17 March 2005).

Tablante, N.L., L.E. Carr, G.W. Malone, P.H. Patterson, F.N. Hegngi, G. Felton, and N. Zimmerman. 2002. Guidelines for In-house Composting of Catastrophic Poultry Mortalities. Maryland Cooperative Extension Fact Sheet 801.

Virginia Department of Environmental Quality. 2002. Avian Influenza Outbreak Summary. VA. Dep. Env. of Qual. Harrisonburg, Virginia.

Funding for this research and demonstration project was generously provided by the Virginia Department of Agriculture and Consumer Services’ Division of Animal and Food Industry Services in cooperation with the Virginia Poultry Federation.

Composting Hog Mortalities in Nova Scotia: Environmental Impacts

L. Rogers1, R. Gordon1, A. Madani1 and G. Stratton2

1 Department of Engineering, Nova Scotia Agricultural College

2 Department of Environmental Sciences, Nova Scotia Agricultural College

A practical alternative to traditional methods of hog mortality management is practice that is best described as above ground burial with a biofilter (biopile) using composting techniques. This research is an attempt to determine the water quality impacts associated with managing hog mortalities using biopiles built on soil surfaces. A hog mortality management system was established at the Bio-Environmental Engineering Centre (BEEC) located in the AgriTECH Park (Nova Scotia Agricultural College) in Bible Hill, Nova Scotia, Canada.

Three different cover treatments (i. sawdust, ii. hog manure pack and iii. hog manure pack with tarp) over carcasses (700 through 900 kg dead-stock per surface area), replicated twice, were investigated over three trials (2001 through 2004). Leachate and surface runoff from biopiles were monitored with calibrated tipping buckets and water samples were collected during flow events and analyzed for various water quality parameters (E. coli., NO3–N, NH3-N, SRP, BOD5, etc.). The sawdust cover provided for higher temperatures and better carcass decomposition in both the primary and secondary phase compared to the other treatments. The sawdust cover had the lowest leachate and surface runoff volumes and lowest leachate and surface annual loads for SRP (0.186 and 1.18 kg ha-1yr-1), N03–N (10.5 and 4.87 kg ha-1yr-1), NH3-N (2.25 and 2.16 kg ha-1yr-1) and E. coli (8.17 x 107 and 4.19 x 108 CFU kg ha-1yr-1) compared to the other treatments. The sawdust cover end-product, however, had a lower nutrient content (3.04. to 3.42 g kg-1 N, 0.41 to 0.83 g kg-1 P and K 0.21 to 0.84 g kg-1 DM K) than the other treatments.