Page 12 - NPN0922

Insights into poultry waste composting systems
Industry supports ongoing improvement in animal welfare outcomes.
NFF’s view on phase-out of conventional cages
THE National Farm- ers’ Federation re- leased a statement stating that it was dis- appointed by the new Poultry Standards and Guidelines released by the Federal Gov- ernment on Thursday August 18, 2022.
“The rushed phase- out of conventional cages over just 10 years, with no plans announced for compen- sation or support, could spell the end for many family-owned egg pro- ducers.
NFF chief executive officer Tony Mahar said, “Industry sup- ports ongoing improve- ment in animal welfare outcomes, but these processes must be led by science and consider the impacts on farmers and consumers.”
“Eggs are an afford- able source of protein and a much-loved sta- ple in the weekly shop.
“Both affordability and supply will suffer if this rushed phase-out goes ahead.
“The egg industry is already struggling with spiralling costs.
NFF CEO Tony Mahar.
From the NFF’s per- spective, significant consultation and juris- dictional harmonisa- tion efforts with pro- ducers must now occur.
“We’re seeing these challenges manifest in egg shortages on super- market shelves.
“Now the plan is to worsen this, by forcing farmers to discard cag- es that in many cases they’re still paying off,” Mr Mahar said.
THE following outlines the distinguishing charac- teristics of the main types of composting systems that could be suitable for poultry waste compost- ing.
ished in about six weeks – if the compost is to be on-sold to another user, a longer composting period of at least 12 weeks is rec- ommended
agreed period, after which the bin is exchanged for an empty one.
for the Ecodrum, by rota- tion of the drum.
building or roof
• Odour and leachate
Because all systems aim to control the composting process by manipulating temperature, oxygen and moisture, they are varia- tions of a common theme.
• Windrows can be out- doors or under a roof
An odour control system is fitted.
Though these can be used in on-farm composting op- erations, the expense can be difficult to justify for all but the largest farm opera- tions.
channel, 2–4 weeks – fur- ther curing usually needed. The choice of compost- ing system or technology is generally governed by the
The most prevailing type of system is the turned windrow or pile – see Fig- ure 5.
It is an example of a ro- tating drum system that is designed to improve mix- ing and aeration during composting – see Figure 7, right.
Features and areas to note with an aerated static pile system:
posed operation and prox- imity to neighbours – dis- tance, topography, prevail- ing winds
It is adequate for process- ing many types of organic wastes, including mortali- ties.
Features and areas to note with a composting bin system:
• Medium capital and op- erating costs
• Potential problems from dust, odour or bio- aerosol emissions
To maintain optimum composting conditions, windrows are managed by turning the mass with either a front-end loader or a specialised windrow turner.
• Most widely used sys- tem for mortalities where the bins are progressively filled over 1–2 weeks as carcasses are collected
Features and areas to note with a forced aeration system:
• Less flexibility – care- ful preparation of starting materials is essential
• Size of available land and desired processing ca- pacity
The windrow system is particularly suitable for on- farm composting for sev- eral reasons.
• Significant capital cost because a roof is usually needed to protect from heavy rainfall
• Often called ‘in-vessel’ composting, these are scal- able systems typically with aeration and odour control
Features and areas to note with an agitated bay or channel system:
It is simple and relatively cheap to set up and operate. Windrows need more space than other systems, and in rural areas, likely suitable sites are easier to find for space and buffer
• Aeration by moving compost from one bin to the next in succession
• Automated, space-effi- cient
• Care needed for effec- tive control of odour and leachate.
Many variations of fully controlled and scalable containerised composting systems are available com- mercially.
following key factors:
• Types of material pro-
Though mortalities can be composted in open windrows or piles, most poultry operations find that a bin system is ideal for regularly disposing of small quantities of carcass- es – see Figure 6.
For instance, the Ecod- rum system has also been used for poultry mortality composting in Australia.
Two examples of such systems are shown in Fig- ures 8 and 9.
cessed
• Location of the pro-
• Low processing costs – simple to operate
• Significant capital cost to buy outright unless the container is leased under a service agreement, as for the BiobiN
• Medium-high capital and operating costs
• Compost can be moved out and stored after about six weeks composting.
• Medium to high operat- ing costs
• Flexible system – both forced aeration and me- chanical mixing are used
The BiobiN is fully con- tainerised and aeration is controlled by fan.
Highly sophisticated forced aeration systems are commercially available.
control
• Retention time in bed or
• Forced aeration by fan
• Some control of temper- ature and aeration speeds up composting – further curing usually needed.
• Investment and operat- ing costs.
Though on-farm poultry operations most commonly use a windrow pile system or bin systems – particu- larly in North America – farms and agribusinesses near small towns or peri- urban areas may need to consider other options with better biosecurity and odour controls. AgriFutures Chicken Meat
Figure 5. Two different types of turned windrows or piles. Photos: J. Biala, University of Queensland
Figure 6. Examples of mortality composting bin designs Photo: blancharddemofarms. org/practices/animal-mortality-composting
Figure 7. Examples of containerised composting systems, with the BiobiN and the Ecodrum.
Figure 8. Aerated static pile. Photo: Washington State University
Figure 9. Agitated bay or channel. Example shown composting chicken manure in
a glasshouse. Photo: Washington State University
distances.
On-farm composting op-
Forced aeration systems – with fans for aeration – improve process control.
erations often have another advantage over commer- cial operations in urban areas – more time.
They do not necessarily produce compost of higher quality than mechanically turned windrows, but they usually do it faster.
In windrowing, compost- ing for extended periods helps the process perfor- mance.
Specialised mortality composting services are al- so available in some areas.
Features and areas to note with a windrow system:
These typically involve a period of composting at the poultry facility, then the process is completed at a commercial facility.
• Low capital and pro- cessing costs
• Flexible for a range of wastes – suitable for mor- talities, subject to appropri- ate controls
The most common exam- ple of this approach is of- fered with the BiobiN – see Figure 7, left.
• Aeration by specialised turner or front-end loader
It is delivered for the poultry farm to fill over an
• Aeration by fans and,
• Beds are covered in a
Page 12 – National Poultry Newspaper, September 2022
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• Compost can be fin-