The facts of life and death – correct carcass disposal an essential part of biosecurity plans
By Dr Sarah-Jane Wilson, Livestock Biosecurity Network Northern Regional Manager
Death, unfortunately, is one of the most inescapable elements of life and one that, when it occurs within the livestock production chain, raises a litany of biosecurity issues.
Animal carcasses can pose a serious risk to both human and animal health, can jeopardise biosecurity and impose a range of environmental impacts if not properly disposed of. These risks can include polluting water courses, spreading disease and interfering with community amenity.
The old practice of simply leaving a carcass anywhere in the paddock to rot simply does not stack up in a modern livestock industry where the implications of incorrect carcass management are better understood.
In fact, depending on where you live, there may be local, state or national regulatory requirements that relate to your on-farm waste management procedures and I encourage you to make yourself familiar with these obligations.
We strongly recommend carcass disposal is integrated into your on-farm biosecurity plan and that you consider the methods available to dispose of animal carcasses or animal waste products including hide, gut or bones after home slaughter or wool that is not suitable for baling. Another important consideration is the equipment you may need to assist in this disposal.
If you live on a small farm, your best alternative may be to engage a specialist disposal service as opposed to burial or on-site burning. Again, there may be some regulatory requirements for producers in higher density areas and I encourage you to seek the advice of your local council or departmental staff to ensure you adhere to any applicable guidelines. Generally speaking burial is often the most practical and preferred method of disposal on a small farm if you do not have access to a disposal service.
For all producers, your geographic location and common endemic diseases should be taken into consideration. For example, if you live in a botulism affected area, burning is the recommended and preferred method. Botulism spores can live in the soil for many years, so simply burying the carcass will not suffice.
If you have multiple sudden deaths in your herd or flock, and/or do not know the cause of death, then it is best practice to investigate. Your local veterinarian or animal health/biosecurity officer may be able to provide further information. If you suspect an emergency or unusual disease, you should report this as soon as possible to your local animal health authority.
For more information, the NSW Environmental Protection Agency and the Tasmanian Environmental Protection Agency provide some good advice, as do most of the other applicable state departments, on how to effectively and responsibly dispose of the livestock carcasses on your property.
Choosing a site (Source: NSW EPA)
If the carcasses must be disposed of on-site, it is preferable to have:
- A burial area at least 100m away from houses or watercourses
- The pit base at least 1m above the level of the watertable
- Heavy soil of low permeability and good stability
- Good access to the site for earthmoving machinery and stock transport unless the stock are to be walked in for slaughter.
Other pit considerations (Source: Tas EPA)
- Sawdust can be added to the bottom of pits to reduce risk of leachate generation
- It is not recommended that lime be added to pits unless there is a biosecurity reason for doing so as this will reduce the decomposition rate of the carcasses
- Surface drainage should be directed away from the pit location by setting up diversion drains up slope of the pit location
- When full, the pit must be covered with a minimum of 1m soil. The soil should be mounded over the pit to prevent rain collecting and it should be remembered the pit cover will subside as the carcasses break down.
If you need to burn (Source: NSW EPA)
- To reduce swelling during decomposition, the abdomens and paunches of all the carcasses should be opened to allow gases to escape.
- The carcasses should be sprayed with sump oil if immediate burial or burning is impractical.
- They should be heaped in a secluded spot away from watercourses and sump oil should be spread liberally over the heap. The oil discourages flies and scavenger and the heap can then be burned later.
Planning ahead for what to do with a carcass or, multiple carcasses in the event of a natural disaster, can substantially reduce the stress of the moment. It can also make a dramatic contribution to the biosecurity soundness of your property and our greater livestock industries.
Here at LBN we’ve designed a small template to assist producers in thinking through the options that best work for them. This can be found at: http://www.lbn.org.au/farm-biosecurity-tools/on-farm-biosecurity-planning-tools/.
- Dr Sarah-Jane Wilson is the Livestock Biosecurity Network’s regional officer for Northern Australia. She can be contacted or 0437 725 877 or email firstname.lastname@example.org.