Annual management to reduce risk
Sheep producers have always used an integrated approach to managing flystrike risk in their flocks. For most this involved mulesing, crutching, shearing and jetting at times during the year that minimised the risk of flystrike. The decision to stop mulesing requires each sheep producer to re-assess not only their breeding program but also their annual management calendar, so that flystrike risk can be minimised. Over time the breeding of sheep with less flystrike susceptibility may reduce the reliance on annual management and chemical treatments for flystrike treatment and prevention.
Special insights into managing flystrike risk in non-mulesed sheep are being gained at the Sheep CRC’s Information Nucleus (IN) flock sites across Australia. The approach being used in the Sheep CRC flocks is detailed below, to assist producers in planning for the management of non-mulesed sheep in their business.
After assessing the following it is suggested that a Preventative Treatment Plan and an Annual Flystrike Management Calendar be developed by ram breeders and producers using the templates:
Flystrike management in non-mulesed sheep
After deciding to cease the practice of mulesing in the IN flocks in 2008, the Sheep CRC and its participants are managing for reduced risk of flystrike in the 8 flocks, using integrated programs tailored to meet local climate and management requirements. The flocks are located at:
- Armidale, NSW
- Trangie, NSW
- Cowra, NSW
- Hamilton, Victoria
- Rutherglen, Victoria
- Struan, SA
- Rosedale SA
- Katanning WA
Each flock contains a range of bloodlines with differing flystrike susceptibility (Score 1-5), so the challenges faced in managing flystrike in these flocks are similar to those faced by commercial sheep producers.
Flystrike management for the Information Nucleus flocks
The Sheep CRC’s Information Nucleus Flocks (IN) have been non-mulesed since 2008.
Because the IN flocks were set up to collect important experimental data on genetics and traits (including production characteristics and wrinkle) of economic importance to the industry, some of the flystrike management practices available to commercial producers cannot be applied in the IN flocks. The following constraints on management of the IN flocks apply:
- No lamb shearing of Merino or Border Leicester x Merino lambs is allowed
- Ewe and wether progeny need to be shorn annually with about 12 months wool
- Because genetic diversity is a requirement there will be some sheep particularly susceptible to flystrike eg. with heavy breech cover and wrinkle
- Culling susceptible sheep or selecting for flystrike resistance is not possible
- Preferential management or preventive chemical treatment of flystrike susceptible sheep within a mob (management group) is not accepted.
Therefore special flystrike management procedures across the whole flock are needed. It is also important to note that the IN flock research work is comprehensive and represents a large investment by industry to collect data on the animals’ performance. It is vital that the animals are able to express their genetic potential fully in the trial work.
Download two CRC press releases on managing non-mulesed sheep at Cowra and Turretfield Research Stations and a third press release on managing unmulesed sheep (see below).
Prevention of flystrike in Information Nucleus flocks
Main points:
- Dock tails to 3 joints in length (tip of vulva)
- Where possible, time crutching so that the breech wool is short during high risk periods
- Control internal parasites and nutritional scouring
- Use low risk paddocks for the most susceptible mobs
- Treat with a registered insecticide when necessary
- Strategically use fly traps
Tail length is important to avoid sun damage and excessive dag formation. Better too long than too short. The long established recommendation is to dock tails at the third joint.
Crutching should be timed so breech wool is short and devoid of dags or urine stain during periods of high flystrike risk.
Internal parasite control is crucial to minimize scouring and/or dags which will attract flies. Refer to
Wormboss for internal parasite control.
Paddocks that are open and more exposed will harbour fewer flies than paddocks with trees, waterholes and shelter from wind. These low risk paddocks are best used for mobs most susceptible to flystrike eg lambs after marking.
Treat with a registered insecticide using a
preventive treatment plan. Ideally treat just prior to risk periods. The range of chemicals available with their respective label claims for protection periods
are:
- Organophosphates 3-6 wks (some chemical resistance)
- Spinosad (Extinosad®) 4-6 wks
- Ivermectin 12 wks
- Cyromazine 10-14 wks
- Dicyclanil (CliK®) up to 6 mths
- Magik and CLiK-Plus contain both dicyclanil and diflubenzuron and are effective against both flystrike and lice.
The LiceBoss™ Products module provides a complete listing of products containing these chemicals –
www.liceboss.com.au or download the
DAFWA summary article. The LiceBoss™ WoolRes module allows the calculation of wool residues from different products and ability to meet different residue targets.
For medium to long term protection CLiK® is recommended. It has the following features:
- Insect growth regulator with low mammalian toxicity
- Up to 24 weeks protection possible against body strike and probably nearly as long against breech strike
- Can be used offshears or with long woolled sheep (to 3 months pre-shearing)
- No chemical resistance
- Easy application
Trials with CLiK® have shown that strategically timed crutching or shearing and delaying treatment until the protection provided by crutching/ shearing has waned (approximately 6 weeks after crutching) it can protect sheep through most danger periods providing other measures (eg prevention of scouring, freedom from footrot, dags etc) are properly carried out.
Repeated reliance on one chemical is more likely to lead to resistant strains of flies developing. Where management considerations permit, rotate chemical groups to avoid development of resistance.
Wool harvesting intervals, meat withholding periods and export slaughter intervals for the above chemicals are listed on the
Liceboss™ website.
Use of low risk paddocks is recommended for the most susceptible mobs, including young sheep, those known to have fleece rot or lumpy wool and sheep not under current chemical coverage.
Fly traps (Lucitraps) can be used both to indicate current fly populations and to reduce fly numbers. The recommended number of traps for flystrike suppression is one trap per 100 sheep. Traps and chemicals can have previously been available from Bioglobal Pty Ltd (ph: 03 5941 1234). Producers should check for current availability of the product.
Alternativey, home-made bait bins can be used though they are not as effective or selective as Lucitraps. Bait bins are made using a large and sealable container, such as a garbage bin or 200L drum. The container should be painted bright yellow as this attracts flies. A sealable lid is required to enable the bait to be replaced as required, but to exclude ants, birds etc. A series of about 15 small holes 4-5 mm in diameter should be made close together and high up on 2 sides of the bin. The bait can be liver, other offal or a whole or partial carcase, adding water to a few centimetres up the container, without covering all the bait. One litre of 20% technical grade sodium sulphide can be added to provide the immediate smell (Source: NSW Government Industry and Investment Primefacts. Primefact 842 Trapping Blowflies).
Recognising high risk periods and monitoring for flystrike
Producers will have a good idea of the normal danger periods for mulesed sheep. With non-mulesed sheep additional vigilance and monitoring will be required to develop an understanding of the danger periods and thresholds. As knowledge develops, the calendar of preventative treatment can be modified and upgraded.
Prediction or onset of weather conditions that increase risk and observation of strikes in susceptible sheep should be the trigger for action and more vigilant monitoring of flocks.
Use of fly traps will also give a good indication of the presence of Lucilia cuprina and periods of population build up.
Preventative Treatment Planner template
Preparing your own Flystrike Management Program
Because of variations in the conditions, sheep types and farm enterprises it is important to develop your own flystrike management program. It should take into consideration;
- normal seasonal climatic conditions
- management options including crutching
- key dates in the farm operations calendar
- use of safe paddocks
- periods of labour shortage for monitoring and treatment
- application of emergency treatments if necessary
- history of chemical usage (including lice treatments) with consideration of fly chemical resistance risks.
Using the Preventative Treatment Planner Template and the Turretfield example as a guide, complete the template for each class of sheep on the property.
For each class of sheep list;
- Breed
- Date of birth
- Date of weaning, shearing, crutching, sale and/or slaughter
- Identify the periods of flystrike risk for this class of sheep
- Identify the flystrike and/or lice treatment that will be applied to reduce that risk
- Identify the Withholding Period, Wool Harvesting Interval and Export Slaughter index for the chemical being used
- Identify the period of flystrike protection that will be achieved from the treatment
In completing the template, keep in mind the availability of labour to monitor, crutch, shear and treat sheep throughout the year. If a key sheep operation clashes with cropping or harvesting time – modification of the sheep program should be considered to avoid the period of peak labour demand.
Consider the chemical treatments that will be required to cover the other periods of high risk.
Review allocation of mobs to paddocks, so that highest risk mobs are placed in lowest risk paddocks for flystrike.
Consider a trapping strategy;
- Traps for monitoring fly populations
- Traps to suppress population build up
- Record planned trapping times on the Preventative Treatment Template
Develop a strategy to reduce dag and stain;
This calendar summarises the information from the Preventative Treatment Plan into an annual action plan, that categorises the flystrike risk, labour availability, key activities and flystrike management requirements for the month.
Preventative Treatment Plan prepared for Turretfield Research Station, South Australia
Annual Flystrike Management Calendar
This calendar summarises the information from the Preventative Treatment Plan into an annual action plan, that categorises the flystrike risk, labour availability, key activities and flystrike management requirements for the month.
Implementing an integrated flystrike prevention program
- When developing a plan ensure that everyone involved with sheep management has some input.
- Write down the plan and display it where it will be seen regularly.
- Review the plan periodically to ensure it is still relevant and appropriate.
- Record actions that have occurred and make notes about any concerns, issues and ideas.
- Remember that the success of an integrated program relies on all of its components being carried out appropriately. One component missing or performing poorly can jeopardise the whole program.
Acknowledgements:
Technical material in this section came from presentations by Peter James, Queensland DPI, Brisbane, at two Sheep CRC workshops in mid 2008 on parasite management. Documentation was prepared by Ken Geenty, Peter James and Deb Maxwell. The example preventive treatment calendar for Turretfield was prepared by Darryl Smith.
Research flocks in Western Australia
In April 2008 the Department of Agriculture and Food Western Australia (DAFWA) announced that it would cease mulesing of sheep on its research stations.
Monitoring and management of the DAFWA research flocks since that time is providing sheep producers with important insights into effective management strategies for non-mulesed sheep and the factors affecting flystrike risk.
Marketing wool from non-mulesed sheep
The wool supply chain is seeking information on the mulesing status of wool so that customer needs, in terms of product specification can be met. The AWEX National Wool Declaration (NWD) provides sheep producers with the opportunity to declare the mulesing status of wool sale lines and ensure that buyers and processors make informed wool purchasing decisions.
A recent AWI/DAFWA survey indicated that potentially 18% of the Australian clip will be from non-mulesed sheep in 2008/09. At present the levels of declaration are lower than this with approximately 3% currently declared as Not Mulesed (NM) and 3% as Ceased Mulesing (CM).
For producers who have made the decision to stop mulesing, completion of the NWD is an important step in demonstrating their practices to the market place. NWD forms are available from your wool broker or the AWEX website.
Information on the quantities of declared wool can be found at on the
AWEX website.
Case studies of producers
We have some case studies available for download - see below.
Development of FlyBoss
The Sheep CRC is currently developing an important new tool to assist with the management of flystrike in the Australian sheep flock. FlyBoss will be launched in January 2010.
It will provide the most up to date information on managing flystrike risk in sheep and breeding flystrike resistant sheep and will replace this Managing Flystrike site once it is launched.
CJ Hawkins Homestead, University of New England, Armidale NSW 2351