On-Farm Mortality Composting Practices Dale W. Rozeboom Department of Animal Science, Michigan State University Animal Mortality Composting Workshop, August 27, 2015 28950 Penrose Road, Sterling, Illinois
Key Topics for Today The importance of dead animal management. Methods of managing on-farm mortalities. How composting works to recycle nutrients.
Intent of Dead Animal Laws Protect human and animal health Reduce risk of disease transmission. Control flies, vermin, and scavenging animal problems. Protect environment Ground and surface water Air quality
Other methods of management Burial on-farm or in landfill Rendering Incineration Gasification Alkaline hydrolysis Anaerobic digestion Feed for other animals
Composting The controlled biological decomposition of organic material under (aerobic and anaerobic) conditions... It is not above ground burial
Composting Is done so that storage, handling and land application of compost can be done without adversely affecting the environment or people. Animal carcasses no longer recognizable Dead animal management is aesthetically acceptable and not a nuisance to other people Composting recycles nutrients.
Composting works effectively
How to compost mortality?
Microorganisms cause decomposition Bacteria Majority of activity Thermophilic heat producing Decompose sugars, starches, proteins, fat and some cellulose Actinomycetes More cellulose decomposition Earthy odor Fungi More cellulose decomposition
Best conditions for active composting Moisture content range of 40 to 60% Carbon-to-nitrogen ratio range of 15:1 to 35:1 Amendment particle size range of 0.5 to 2 inches O 2 ph range of 5.5 to 9.0
Composting conditions to be managed Amendments Moisture Carbon/nitrogen ratio Particle size ph Percent recycled compost Inoculation Pile shape and depth Water additions Aeration schedule Retention time Curing time
Amendments Sawdust Wood chips Chopped straw Grain hulls Other crop residues Fresh manure Manure with bedding Wasted feed Shrub and tree trimmings Grass clippings Leaves Shredded cardboard or newspaper Finished compost Bulking agents, carbon sources
Spartan Compost Recipe Optimizer http://msue.anr.msu.edu/program/info/managing_animal_mortalities Microsoft Excel Uses Solver Add-In Least cost recipe User defined constraints User defined amendments
Materials library
Performance summary
Compost amendment recipe Item Blend Dairy manure compost Horse stall bedding Finished swine mortality compost Dry wood shavings Moisture, % 48.3 Mineral matter, % 5.91 N, % 0.761 P, % 0.176 P 2 O 5, % 0.402 K, % 0.512 K 2 O, % 0.617 Ca, % 0.864 Mg, % 0.190 Na, % 0.129 S, % 0.146 C, % 24.113 B, ppm 7.4 Fe, ppm 1308.6 Mn, ppm 86.8 Cu, ppm 16.5 Zn, ppm 46.7 C:N 31.8 ph 8.72
Amendment dead animal relationship Dead animal density (lbs./ft 3 ) in compost Average 10 Range 5 to 15 Optimum depends on desired speed of composting process Weight rule of thumb: 2.5:1 ratio of amendment to animal tissue
Observations when composting Active composting Temperature increase to 130 to 155º F Steam rising from compost material Repeated cycles of activity accompanied by heat production With aeration of compost» Aerate when temperature decreases to < 100º F for 7 days Moisture content kept at 40 to 60% Rapid decomposition into CO 2, water, heat, minerals, and compost (humus)
Temperature indicates activity 160 140 120 100 80 60 40 20 0 13-Mar 15-Apr 13-May 15-Jun 15-Jul 10-Aug 11-Sep 16-Oct 13-Nov 15-Dec 6-Jan 18-Jan 8-Apr Temperature (degree F) P il e 1 P il e 2 P il e 3 P il e 4
Monitoring temperature Dan Short, UW-Extension/CALS, 2000 Dan Short, UW-Extension/CALS, 20000
Steam indicates activity
How to compost a dead animal? When to start a new batch Practically depends on mortality frequency Time of year (if no active or curing piles) Size of composting bin or area Carcass preparation Chilling or freezing before composting slows or prevents activity Carcasses can be left whole cutting open is not necessary
How to compost a dead animal? Base of pile 12 to 24 inches of unused, dry amendment Place dead animal 6 inches or more from outside edge of pile Small carcasses (< 150 lb.) may be laid in layers Place minimum of 15 cm amendment between layers Surround carcass with 6 to 12 inches of amendment Best to active compost or finished compost
Carcass placement for composting
Final steps when starting a batch Cover entire pile with 6 inches fresh, clean amendment Acts as a Biofilter to control odor, fly, and vermin Maximum pile depth of 5 to 6 feet
Reshape after collapse
Aeration accelerates decomposition Mixing and moving adds air to the compost No limit on mixing frequency, but apply fresh cover each time Steve Boyles, Ohio State University
Finished compost Dark, humus-like No soft tissues Little odor Steve Boyles, Ohio State University Bones easily crumbled during the mechanical spreading process. If not, then they should be gathered and placed in a new batch of compost for further decomposition. Density (lbs./yd 3 ), range of 800 to 1200
References Rozeboom, D.W., J.G. Sirera, B.E. Straw, L.M. Granger, P.J. Fedorka- Cray, and B.J. Thacker. 1997. Disposing of swine carcasses and afterbirth by composting. Final report to state of Michigan. File Number 19.42, ANS Mimeo Number 369. Rozeboom, D.W., D. Ross, T.A. Guthrie. 2013. "Carcass composting A guide to mortality management on Michigan cattle farms." Extension Bulletin E3197. Michigan State University Extension, July.
Thank you! Dale W. Rozeboom Professor/Extension Specialist Department of Animal Science Michigan State University 2209 Anthony Hall East Lansing, Michigan 48824 Ph: (517) 355-8398 Fax: (517) 432-0190 http://www.msu.edu/~rozeboom/ http://web1.msue.msu.edu/aoe/pork/