CASE NOTES


Lessons from a regional lice control project in THE TABLELANDS OF NSW

J Eppleston and B Watt, Central Tablelands Local Land Services, PO Box 20, Bathurst, NSW

This paper was first presented at the Combined ACV/ASV Annual Conference, Hobart 2015 and appears in the Proceedings of the Combined Australian Cattle Veterinarians and Australian Sheep Veterinarians (ACV/ASV) Annual Conference, Hobart 2015
Posted Flock & Herd June 2015

ABSTRACT

In response to concerns about an increasing lice problem in a fine wool growing region of the central tablelands of NSW we conducted a project aimed at controlling lice on a group basis. This paper describes the results achieved during the three year project and highlights some of the challenges and obstacles encountered to achieving good regional lice control. The experiences of this project can be used to highlight issues to be considered should a similar approach be taken in other sheep producing regions.

INTRODUCTION 

Lice were estimated to cost Australian sheep producers $123 million pa in 2006 (1). Following recent anecdotal reports of increased lice prevalence across Australia (2), we estimated the apparent and true local between flock prevalence of lice in the central tablelands region of NSW in 2011 at 16.5% and 30% respectively (3).

Subsequently we were approached by a group of specialist wool producers who expressed interest in controlling lice in their region. Previously (4) we described the establishment and methodology used in the ensuing AWI-funded project which aimed to determine the practicality of controlling lice on a group basis.

This paper will present the outcomes from the project and discuss some issues associated with group control of lice. Lessons from this work will be of value to other groups considering regional lice control.

METHODS 

Group establishment. A series of local meetings confirmed support from the majority of producers in the region and collaboration between the producers and experienced local animal health staff identified group boundaries. Stage 1 identified 15 flocks and 12 months later a second stage incorporating another 7 flocks was added to expand the group to a total of 22. Soon after the group was established the lice skills of group members were updated at a technical workshop and demonstration day.

Survey of management calendars and risk identification. A questionnaire was completed at individual farm visits to identify enterprises, management calendars, lice history and other risk factors associated with each flock. 

Flock inspections and monitoring. Each flock was inspected visually for the presence of lice (5) at or before each shearing for the duration of the project and these shearings are referred to as ‘Treatment”, ‘Assessment” and ‘Confirmation’ shearings, respectively. However because the project was terminated prematurely no confirmation inspections were undertaken.

Lice Management Plans. Using data compiled from the questionnaire, from farm visits and direct farmer feedback, individual flock risk management plans were developed and distributed to group members who were asked to modify them as required. Risks to the bio-security of the project, however identified, were recorded and managed as they occurred. However this was heavily dependent on local observation and then communication with the project team.

RESULTS AND DISCUSSION 

Farm characteristics. A detailed description of the enterprise mix within the group was presented previously (4). Around half the producers run two separate sheep enterprises and of the 34 enterprises identified, most are either self replacing merinos or first cross ewes. The group runs approximately 77,000 sheep on 270,000 hectares. Most lamb during the autumn winter period and half are shorn during the autumn and half during the spring.

Prevalence observations. A summary of lice prevalence within the group by Stage is presented in Table 1.

Table 1. Lice prevalence and infestation changes for individual member flocks in the Animal Health (Sheep Lice) Bio-security Group.

Stage Flock ID Treatment Shearing Assessment Shearing
Date Lice prevalence Treated Product Date Lice prevalence Treated Product
1 1 Sep-12 High Yes Avenge® Sep-13 High Yes Avenge®
1 2 Oct-12 Mod Yes Assassin® Oct-13 Low Yes Avenge®
1 3 Oct-12 Nil No   Oct-13 Nil No  
1 4 Oct-12 Nil No   Aug-13 Mod Yes Unknown
1 5 Mar-13 Nil Yes Extinosad® Mar-14 Nil Yes Zapp®
1 6 Dec-12 Mod Yes Avenge® Dec-13 Nil Yes Avenge®
1 7 Feb-13 Nil No   Feb-14 Nil No  
1 8 Sep-12 Nil No   Sep-13 Nil No  
1 9 Feb-13 Nil No   Feb-14 Nil No  
1 10 Nov-12 Nil No   Oct-13 Nil No  
1 11 Sep-12 Nil No   Sep-13 Mod Yes Assassin®
1 12 May-13 Mod Yes Assassin® Apr-14 Low Yes Avenge®
1 13 Mar-13 Nil Yes E. Gold® Feb-14 Mod Yes Assassin®
1 14 Nov-12 Nil No   Could not be contacted  
2 21 Jun-13 High Yes Avenge®        
2 22 May-13 Nil Yes Diazinon®        
2 25 Oct-13 Mod Yes E. Gold®        
2 32 Oct-13 Nil Yes Diazinon®        
2 33 Apr-13 Mod Yes E. Gold®        
2 41 Apr-13 Nil Yes Avenge®        


Of the 20 flocks in the study, seven were detected with lice at the ‘Treatment’ Shearing (four Stage 1 and three Stage 2 flocks) representing a prevalence level of 35%. Thirteen of the Stage 1 flocks were reinspected at their ‘Assessment’ shearing, and a total of six (46%) were detected with lice. These six flocks comprised three (of four) that were still infested from the previous year and three new infestations previously undetected. However this may be an under estimate of prevalence as without the Lice Detection Test we risked missing flocks  with a low level recent infestation.

These prevalence figures suggest that the lice problem within the group was not being reduced using the current approach. Reasons for this recrudescence include; i) existence of one member who failed to treat adequately, ii) existence of an active sheep trading operation on the boundary of the group, and iii) introductions of infested re-stocker sheep.

Treatment choices. All infested flocks were treated at the relevant shearing (13 treatments) to eliminate lice while another seven flocks assessed as not having lice were also treated with a lousicide at shearing. Most (13 of 19) used a pour-on product rather than a dip and the most popular pour-on was imidacloprid (Avenge, Bayer). Despite the risk of chemical resistance one producer chose to use an IGR product but this was in a flock not considered infested. The remaining producers utilised chemicals generally considered effective by project veterinarians.

Quality of treatment. The project veterinarian attended the first day of shearing in a flock with a long term lice problem and demonstrated treatment on the first few races. However most treatments were not inspected by project staff as pour-on application methods had previously been demonstrated at the lice workshop.

Topographic challenges. The steep landscape, particularly in the eastern portion of the region, makes both mustering and secure fencing difficult. Native and feral animals also make secure fencing challenging.

Risk assessments. A detailed description of risks identified at the initial survey was provided previously (4). In summary ;

Bio-security and lice management plans. Bio-security was emphasised at the lice workshop and while group members were asked to advise project staff when they identify risks, including bio-security breaches, none were reported. Ongoing high risk flocks in and bordering Stage 2 were approached by project staff and advised of the Lice Group project. Further, technical advice and treatment options were given to the owners of the risk flocks by District Veterinarians.

Draft individual property management plans were developed and distributed to all owners who were asked to modify and update the plans and return to project staff. However no feedback was received from any group member on whether these plans were modified or carried out by the flock owner.

Views of landholders. Despite early commitment by the majority of producers, we noted variable commitment to the project as the project progressed. For example project staff were not advised by members of developing lice risks within the area including continued infestations in problem flocks. Staff only became aware of these risks during occasional discussions with individual members.

Communication between the project staff and producers was difficult due to distance, the lack of mobile phone coverage and infrequent internet use. As a result we initiated a mail-out Newsletter to keep the project in the minds of producers.

Project Review. These concerns prompted a review of the project and one outcome was to conduct a number of other group activities to increase the involvement of producers. For example an information day was conducted to discuss animal welfare and the developing dry seasonal conditions. This meeting was well attended and most members were actively involved. At the meeting we flagged holding a wool handling workshop and while most members indicated their support insufficient were able to attend and the meeting was cancelled.

We also investigated the possibility of involving an extension expert to survey producer attitudes to the project and lice control in general. To this end we developed a proposal with an academic at Charles Sturt University but because of the later management changes this was not progressed further.

Changes to project management. The new Local Land Services (LLS) organisation was created during the project and this involved several boundary changes meaning that the project site was no longer under the jurisdiction of the Central Tablelands Local Land Services. We subsequently surveyed members on how they would like to continue lice management in their region. Despite a low response rate (6/20) the majority indicated they wanted the project to continue. A follow up phone call to non-responders suggested that most lacked commitment to the project. There appeared to be general landholder support for broadening the scope of the group to other bio-security issues, while keeping a core focus on sheep lice. 

The project was terminated when the boundary changes described above meant that the region was outside of the jurisdiction of the project team.

CONCLUSIONS

A group approach to lice did not result in a reduction in the prevalence of lice in the study region. Reasons contributing, at least in this situation included:

Future groups should:

ACKNOWLEDGEMENTS 

Australian Wool Innovation Ltd provided funding for this project. We acknowledge the contribution of Dan Salmon and Garry Levot for design and technical inputs. LHPA staff including Katrina Crawford, Dennis Ferson, Sam Price and Bill Johnson were vital for the conduct of this program.

REFERENCES 

  1. Sackett D, Holmes P, Abbott K, Jephcott S and Barber M (2006) ‘Assessing the economic cost of endemic disease on the profitability of Australian beef cattle and sheep producers. MLA report AHW.087 (MLA: Sydney)
  2. Littlejohn J and Schroder J (2009) Australian Wool Innovation investments and activities in sheep lice control In: ‘Proceedings of the Annual Conference of NSW District Veterinarians, Port Macquarie’ pp 23–27
  3. Popp S, Eppleston J, Watt B, Mansfield S and Bush R (2012) The prevalence of lice (Bovicola ovis) in sheep flocks on the central and southern Tablelands of New South Wales Animal Production Science 52 659-664
  4. Eppleston J, Watt B and Crawford K (2013) A regional lice control project in the tablelands of NSW Proc. Aust. Sheep Vet. 2013 Conf. (Albany). pp. 53-55
  5. Joshua E, Junk G and Levot G (2010) Sheep lice Available at www.dpi.nsw.gov.au/primefacts [Verified 15 July 2013]

 


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