K. Shibi Thomas, V.Jayalalitha and P. N. Richard Jagatheesan
Veterinary University Training and Research Centre,Tamil Nadu Veterinary and Animal Sciences University (TANUVAS) 7/2, Kozhi Pannai Road, Kottapattu, Trichy – 620 023 -Tamil Nadu
Types of poultry waste
1. Poultry manure
2. Hatchery waste
3. Slaughter house and processing plant waste
4. Dead bird
1. POULTRY MANURE
Two main types of waste are produced by poultry enterprises depending on the rearing system adopted on the farm
• Poultry litter – Waste from deep litter systems
• Cage layer waste – Excreta collected under the cages, spilled feed and feathers.
Poultry manure contains
|· Nitrogen||· Zinc|
|· Phosphorus||· Copper|
|· Potassium||· Boron|
|· Calcium||· Iron|
|· Sulfur||· Manganese|
• Oldest, cheapest and feasible method
• Dried under sunlight and depends on lengths of time, climate and humidity.
• Drying the manure with heat results in loss of energy and nitrogen.
• Thin bed drying prevents the breeding of flies, reduces obnoxious odours and maintains the nutrient value of the manure particles.
• The faster the manure is dried, the higher is the nitrogen value.
• Deep stacking of poultry waste produces considerable heat and had been shown to destroy coliforms.
• The maximum temperature was reportedly attained in 4-8 days.
c. Poultry manure as organic fertilizer
• Poultry manure applications increase the moisture holding capacity of the soil
• Improve lateral water movement, improves irrigation efficiency and decreases drought
• Improve soil retention and uptake of plant nutrients.
• Increase the number and diversity of soil microorganisms.
d. Biogas / Electricity generation from poultry litter
• Poultry litter has a good calorific value for power generation by combustion under controlled conditions.
• The technology for anaerobic conversion of poultry manure to biogas (methane) has been developed.
• Electricity production facilities estimated assuming poultry litter utilization rates of 1000 tons/year, 10,000 tons/year, and 50,000 tons/year for various technologies range from 34–70 kW, 340–700 kW, and 1.7–3.5 MW, respectively.
• Economic analysis accounting for capital expenditures, operation and maintenance costs, litter cleanout and transportation, and recoverable sludge/ash value reveal that gasification at a small scale (100 kW) and medium scale (1 MW) is potentially economically viable compared to anaerobic digestion and combustion.
• Can be stored for long time
• Aerobic bacterial action occurs
• The top foot is composed of fresh manure, the bottom foot is in an anaerobic condition and the central portion is undergoing composting.
• The essential requirement in managing the deep pit is that the fresh, wet material be adequately aerated to remove the moisture.
• To further the composting process and to prevent odours the pit must be watertight so that seepage water cannot enter.
• Little or no odour arising from the pits and manure removal may be delayed for years.
f. Pond disposal
• Fresh poultry manure may be flushed into an open, shallow pond.
• Bacterial action reduces the waste material to a smaller volume.
• Bacterial growth occurs only during the warm months, the use of ponds is seasonal.
• The resulting solution may be spread in its liquid state on farmland.
• Aerobic action produces little odour as the sludge builds up, anaerobic activity takes place and odours may be pronounced.
• Water is poured into the trough to keep the manure fluid and pumps keep the sludge circulating. The effluent is aerated by paddles.
• The addition of oxygen by the paddles increases the activity of aerobic bacteria, greatly reducing the incidence of any odours.
• The material is removed in liquid form and usually spread on the land. The material is practically odourless.
2. HATCHERY WASTE DISPOSAL
• Solid hatchery waste comprises empty shells, infertile eggs, dead embryos, late hatchings and dead chickens and a viscous liquid from eggs and decaying tissue.
• Wastewater comes from water used to wash down incubators, hatchers and chick handling areas.
• Traditional disposal methods for solid hatchery waste include land fill, composting, rendering, and incineration.
a. Power generation
• The hatchery waste can be automatically fed by conveyor belts into a furnace which is equipped with a rotating shredder unit for chopping and grinding solid waste.
• An incinerator system can be used as a furnace to heat the solid and liquid waste to produce steam.
• The steam can power a turbine generator to produce electricity.
• Simultaneously dries the material and separates the fat from the protein and yields fat and a protein meal should be pathogen free.
c. Autoclaved and extruded
• Extruded or autoclaved hatchery waste could be used as livestock feed.
• Hatchery waste should be boiled at 100ºC with a pressure of 2.2 kg/cm2 for 15 min; then boiled again at 100ºC for 5 hours, followed by boiling at 130ºC for 1 h then cooled to ambient temperature.
• Dead embryos could be boiled for 100ºC for 30 min, soaked in cold water for 20 min to remove shells, sun dried for 4d and used in poultry feed.
• The eggs were mixed in a 1:1 ratio with formic and propionic acids for 8 weeks at room temperature.
• The acids act by intervening specifically in the metabolism of the microorganisms involved in spoilage.
• The reduction in the pH creates an environment which is unfavourable for microorganisms. The rapid reduction in the pH diminishes the growth of bacteria which produce butyric acid and ammonia and promotes the growth of lactic acid-producing bacteria.
• The lactic acid is responsible for the low pH necessary for storage of the by-product before being used in animal feed.
• Composting is a common method for solid organic waste disposal.
• The decomposition of organic waste is performed by aerobic bacteria, yeasts and fungi. The composting process kills pathogens, converts ammonia nitrogen to organic nitrogen
• The product can be used as a fertilizer.
• Disadvantages of composting are loss of some nutrients including nitrogen.
• Composting with litter eliminates Salmonella
• The hatchery waste can be mixed with wood shavings to reduce the moisture then composted.
• The composter turns manure, litter, sour feed stuffs and carcasses into compost in 4 days with minimal labour and mechanical devices.
g. Anaerobic digestion systems
• High efficiency process
• Produces biogas for power generation or heating
• The bio-solids may be used as a high quality fertilizer and generation of electricity
• Anaerobic digestion of organic waste by microbial organisms to produce methane and inorganic products
3. SLAUGHTER HOUSE WASTE DISPOSAL
• Rendering is a process of cooking and sterilizing non-edible waste
• Best options for treatment of non-edible wastes by converting waste into meat meal
• Poultry bye-product hydrolyzed feather meal (or PBHFM) or simply Meat Meal.
Advantages of rendering:
• Rendering is more effective and profitable
• Converts entire poultry waste into high protein sterilized meat meal
• Prevents environment pollution by disposing of all biological waste
• Meat meal is used for making animal feed
4. DEAD BIRD DISPOSAL
• Disposal of birds for small farms that cannot construct an incinerator.
• Deep hole may be dug and carcasses buried deeply to prevent worms from carrying infections from the carcass to the surface of the ground
• Deep narrow trench can also be used
b. Pit disposal
• Effective and convenient method for disposal of dead birds.
• 150 feet from the poultry houses and water supply
• Flies and insects should not enter the pit
• The pit should be covered with tar paper or plastic
• The pit should be near the post mortem room
• Practical size for pit is about 1.8 m square by 2.4 m deep with drop tube
• Tight fitting lid on the upper end of the tube to prevent the escape of foul odours and the entrance of flies.
• Burning of the carcass
• An incinerator is a furnace used for burning.
• Incineration process uses electricity, firewood or oil
• Electrical or oil-fired incineration is the best available technology
• Rapid destruction of disease-producing organisms, leaving only a small amount of
• Ash which can be distributed on the land
• Smokeless and odourless burning with minimal air pollution
d. Septic tank disposal
• Breaking down the carcasses and waste products in an electrically heated septic tank by the action of mesophilic bacteria.
• Heat is applied at 37.8ºC and requires 2-3 kwh per day of electricity to maintain this temperature for the two weeks needed for destruction of all but the bones of the carcasses.
• The bacterial action and speed of decomposition can be accelerated by adding lime and hot water at intervals.
• Usually a tank of 2000 litre capacity is required for a flock of 10000 birds.
• Composting reduce and transform organic waste into a useful end product called “compost”.
• Alternate layers of litter and paddy straw and dead birds and water
• Finally, the carcasses are covered with a layer of manure.
• Once full, a final cover of litter is placed over the carcasses.
• The temperature of the compost increases rapidly to 60-70ºC within 10 days.
• Decomposition starts and kills micro-organisms.
• Temperature decreases after 14-21 days later
• At this point, the material is moved to the secondary bins
• Aerated and allowed for a second rise in temperature.
• The compost material can be safety stored
• 10 m3 of bin space is required for every 1000 kg of carcass.
• Rendering is a heating process that extracts usable ingredients, such as protein meals and fats.
• Rendering converts the inedible results from the slaughtering process into meat meal, bone meal, and feather meal
The following methods may be followed as pre-treatment or method for rendering
1. Daily pickup
• Daily pickup of poultry carcasses leads to disease transmission.
• Biosecurity should be practiced.
• Central carcass disposal sites should be used for commercial conditions
• Dead birds can be stored on the farm in freezing condition until they can be rendered.
• Freezing reduces or eliminate pollution and improve conditions on the farm
• Mixes dead birds (which have been ground into 1-inch particles) with a fermentable carbohydrate source, such as sugar, whey, ground corn, or molasses.
• Reduces the pH level so that pathogenic microorganisms are inactivated and the organic materials are preserved.
• Biologically safe, pathogen free safely transported to a rendering plant, recovery of nutrients and recycled into usable foodstuffs or animal feed.
4. Acid Preservation
• Propionic, phosphoric, or sulfuric acid is added to carcasses.
• Stored in airtight, plastic containers
• Eliminate the potential for transmitting pathogenic microorganisms
Advantages of rendering
• Removal of all mortalities from the farm.
• Eliminates environmental pollution
• Nutrient losses, water quality, and recycling for profit increase