Objectives To gain proficiency in estimating daily mortality rates, mass and volumes using published values. To introduce several methods used for mortality management.
Course Materials Required Materials –NRCS Practice Standard, Animal Mortality Facility (Code 316) –Example CNMP Supplemental Resources –Stettler, D. 2001. Mortality Management. Lesson 51 - National Livestock and Poultry Environmental Stewardship Curriculum. Midwest Plan Service and US EPA.
Mortality Management When livestock dies before the slaughterhouse –the producer loses money two ways loses the meat-value of that animal the cost to dispose of that animal Therefore, producers don’t want to deal with mortality –it costs money
Planning for the Impossible... Natural disasters can happen –Flooding (IA, 1993 & NC, 2000) –Snow (Blizzard of 1993) millions of broilers and chicks lost to building collapse and loss of power for heating –Whole herds may be destroyed contagious diseases (FMD, TB, BSE) swine viruses and human flu viruses
Planning for the “impossible” Hurricane Floyd 1999 SE North Carolina
Mortality is a Waste Management Issue A carcass is a concentrated source of organic matter –it is a source of odors –it is a source of undesirable critters –it is a potential source of pathogens –it is a source of nutrients Thus, the mortality problems are similar to manure problems
Mortality Management Manure management system is NOT the mortality management system –no dead hogs in the lagoon they will float as they bloat –no dead birds in the litter spreader picnic for buzzards Law –thou shall not leave dead animals exposed to the environment
Incineration Cremation is a controlled and rapid oxidation of organic matter –this is not coal- oil, old tires and a lit cigarette –greatest utility is for small animals
Commercial Incinerators Complete reduction of volume Destroys pathogens Oxidizes volatile gases (odors) Expensive –initial cost and energy cost Air permit issues –incinerators with greater than 400,000 btu/hr capacity require air quality permit
Composting of Mortality Composting is a controlled, natural process in which beneficial organisms reduce and transform organic waste into a predictable and useful end-product –a good option for both large and small animals –requires some labor and space
Basic Process –Indigenous populations of bacterial and fungi will start to decompose the organic matter when conditions are favorable Moisture - not too wet and not too dry, about 55% moisture by weight aerobic if oxygen is available - creates the most heat, the fastest degradation rate anaerobic if no oxygen available, very slow microbes will utilize the carbon and nitrogen and reproduce
Composting Methods Bins –material is transferred between bins as a means of mixing –common for poultry and baby pigs Passive Piles or Windrows –natural movement of oxygen through the bulking material –with large animals, difficult to turn pile Mechanical
Composting Bins for Mortality Disposal Volume is based on poundage of daily losses –if average 200 pounds of loss per day then need 200 cubic feet of primary is recommended with 200 cubic feet of secondary Width and depth depends on equipment –must be wider than your front-end loader typically 8-feet wide
Finished Carcass Typically only large massive bones are left identifiable after 6 weeks.
Goals Ratio of Carbon to Nitrogen –23 parts carbon to 1 part nitrogen Bulking material provides air space –serves to provide oxygen –serves absorb odors Fresh material should heat rapidly –in 24 to 48 hours, should be greater than 120°F
Operating Procedure Primary heat cycle –10 to 14 days, as oxygen supply decreases, temperature decreases –monitor temperature with long-stem thermometer Secondary heat cycle –move to secondary bins for mixing and to redistribute moisture –15 to 20 days of additional composting
Mortality Management by Rendering Recycles the nutrients contained in the dead animal Requires prompt transport to rendering plant – Transport within 72 hrs (24 hrs is better) – Bio-security measures must be observed
Mortality Management by Rendering Alternatives to prompt transport Freezing Fermentation
Mortality Management by Rendering Advantages Conserves nutrients contained in the dead animals Minimal capital investment unless preservation is used Low maintenance
Mortality Management by Rendering Disadvantages Increases sanitary precautions to prevent disease transmission Storage of animals is required until pickup. Fees charged for pickup Rendering services may not be available.
On-Site Preservation Value-Added Possessing or Quality Preservation This costs money - must be able to get a return on this investment –of course, not paying a fine is a return Maximizes the potential of receiving money for deadstock rather than paying to have it removed
Refrigeration –small animals, lot of electricity, works well Acid Preservation –preserves nutrient content, inactivates pathogens, acids are expensive and hazardous Fermentation –anaerobic deterioration, limited by lactic acid formation, pH ~ 4.5 –pickling On-Site Preservation Value-Added Possessing or Quality Preservation
Livestock Burial The old standard –large animals –need a large area for a few burials Need better control for concentrated burials
Trench Method Convenient and inexpensive –trench is opened, and then progressively backfilled as carcasses are placed –works best for small animals, broilers, chicks, and baby pigs Problems –frozen soils, mud, scavengers
Burial Pit Anaerobic Zone Aerobic Zone Surface water diverted Manhole cover for lid
Burial Pits Solid containment –has solid walls and top –prevents exposure to carcasses –reduces the escape of odors Problems –how to close the pit at end of useful life –could be a point source
Final Thought Mortality is a cost, however, it must be part of the overall production plan Everybody knows the smell of rotting flesh Mortality management is not difficult unless it is an afterthought