ParaBoss Technical Committee member, Dr Peter James, said the key dilemma producers face whenever they introduce sheep is whether the sheep even have lice.
“They can be very hard to find until an infestation has become well established.”
The LiceBoss Treatment Guide makes a hard decision easier, guiding producers through straightforward questions and answers about various on-farm scenarios.
It provides a robust recommendation on what actions producers should take to introduce sheep to maintain your lice-free status. However, it also has less robust recommendations, so that producers can decide on the practices and level of risk they are prepared to undertake.
Each recommendation links to relevant information and tools on the LiceBoss web site to assist in choosing an application method and product. Instructions on how to set up and use application equipment are also included.
The final report in the guide contains questions and answers, a set of LiceBoss recommended actions and links to supporting information to help producers make a decision.
Lice identification can take six months
LiceBoss has seven possible recommendations for managing introduced sheep, but there are a number of factors to consider first, especially when lice may be present, but have not been positively identified.
It may take six months or more for lice infestations to become detectable on a thorough inspection. Key points to remember include:
- – If the sheep have recently been shorn, shearing removes most—but not all—lice; those that remain are hard to find.
- – If the sheep have recently been treated with a chemical the lice have some resistance to, this will kill many, but again, not all lice, with the few remaining generally avoiding detection for some time.
- – If the mob’s recent treatment was applied poorly, with some sheep missing treatment or not being treated correctly, many sheep will be lice free, but those with lice might easily be missed during a mob inspection.
- – If a lousy stray has come on to your property, lice may not be evident in your flock for many months.
When looking for lice choose the most rubbed sheep in the mob, LiceBoss said. Make five partings on each side of at least ten sheep and look for lice in good light with glasses or a magnifying glass. The presence of just one louse means the mob is infested and there will be many other lice present. If these sheep are not effectively quarantined they could transfer lice to any sheep they contact.
Shear and treat is most rigorous option
Dr James said a key factor in managing introduced sheep is the number of sheep purchased compared to the home flock size. Many an unsuspecting ram buyer has brought lice in when buying a small number of rams.
“With a small number of sheep, the most rigorous biosecurity approach is to shear and treat them as soon as they arrive home, and to keep them isolated for a period after treatment according to the label directions for the product used.
“Ideally for rams, this should be done at least seven weeks before joining to avoid any possible handling stress effects on ram fertility.”
Dr James said the ‘shear and treat’ option can be expensive for larger mobs, primarily because one and sometimes a later second premature shearing may be implemented to line up shearing times.
“This can significantly reduce the wool value,” he said.
“We therefore ensured the LiceBoss Treatment Guide could also consider your ability to isolate or quarantine the mob, the amount of wool growth currently on the sheep, and the impact introduction of lice to your flock would have on your business.”
“Next time you are considering introducing sheep, or have found a stray in your flock, immediately think of the LiceBoss Treatment Guide,” said Dr James.
The guide is easy to find at www.liceboss.com.au by choosing ‘Solve your current lice issue’ or Tools, in the main menu.
More information is available from: