Summary
Product stewardship of ectoparasiticides, and for that matter all products sold by an animal health company, should be considered an essential component in the overall management of a product portfolio. Stewardship is a term that encompasses many aspects of a product’s management. This paper provides an overview, with some results, of stewardship work undertaken by Novartis Animal Health with the flystrike preventatives, CLiK® and Vetrazin®.
 
 

Summary
COOPERS MAGNUMÒ IGR an aqueous based pour-on formulation containing 25g/L diflubenzuron, developed by Schering-Plough at their Prospect Research Laboratories, was registered as an off-shears sheep lice treatment in 1999. The extensive research work on this off-shears pour-on commenced in Australia in 1996 but has not been reported outside the National Registration Authority. The following contribution compiles data generated from formulation selection, dose determination, effect of wetting on efficacy, field trials, period of protection and post treatment non infection, wool and tissue residues, scourability and target host, skin and wool safety is presented as are details of some extensions to claims in relation to use on lambing ewes.
 
 

Summary
The application of 25 ppm spinosad to sheep with any length wool, does not lead to harmful residues in wool or meat or OH&S concerns for shearers. Spinosad kills lice quickly and thus rapidly halts the wool disruption caused by lice in sheep with any length wool. A farmer can confidently choose not to treat sheep considered to be lice-free after shearing knowing that if fleece derangement due to lice should occur sheep can be treated with spinosad anytime before shearing and have no problems with wool residues. Spinosad applied by hand jetting cures fly strikes, prevents further infestation of treated wounds or new strikes for 4 to 6 weeks. It is best used tactically in the face of a flywave. In situations where fly waves do not occur predictably every year tactical use of spinosad only when required obviates the need for preventative treatments. It is also very effective as a flystrike dressing at 25 ppm and as a mulesing dressing at 125 ppm.
 
 

Summary
A safety study, a larval implant study, 31 field studies in Australia (3931 Merino sheep treated) and 4 field studies in New Zealand (400 Romney sheep treated) were conducted between 1997 and 2000 with a 25 g/L diflubenzuron spray-on formulation to gain registration of the formulated product as a sheep blowfly control agent. The animals in the larval implant study received 44 mL in two overlapping bands down the backline. All Merino sheep in field studies received 51 mL in 3 bands of 17 mL each; two down the backline and one around the breech. All Romney lambs received 34 mL (weighed <30 kg) in two bands of 17 mL each; one down the backline and one around the breech. The 18 month old Merino sheep in the safety study were treated at 51, 153 and 255 mL per animal. There were no safety concerns or behavioural changes observed in the animals treated.

The larval implant study indicated that diflubenzuron was as effective as cyromazine at controlling the larvae of Lucilia cuprina when applied at similar and at lower rates than cyromazine. In New Zealand studies on Romney lambs treated 3-6 weeks off-shears diflubenzuron provided 11-16 weeks protection against body strike and 8-16 weeks protection against breech strike, which was similar to the protection period provided by cyromazine. The 25 g/L diflubenzuron formulation provided protection against body strike in Merino sheep for 11-20 weeks post-treatment and breech strike for 6-20 weeks post-treatment when greater than 2% strike in the treated sheep was considered inadequate protection.

The Australian sheep blowfly activity at the field study sites was monitored using untreated control sheep or the LuciTrap System (LuciLure attractant) or both untreated sheep and traps. Where both untreated sheep and traps were used there was a poor relationship between numbers of trapped flies and flystrike in the untreated animals, including occasions when rainfall was present.
 
 

Summary
Considerable evidence indicated that Automatic Jetting Races (AJRs) were not being as effective as they should be at protecting sheep from flystrike. Ineffective wetting was believed to be a major contributory factor. To examine this issue and to endeavour to make appropriate modifications to improve AJR performance, a series of experiments were undertaken to investigate the mechanical performance of the equipment to improve their efficiency and efficacy in controlling the sheep blowfly, L. cuprina. Results indicated that significant improvements can be made.

Following the release of the improved AJR design, concerns were held that the improved performance of the equipment may result in excessive pesticide residues in raw the wool. A further experiment was conducted indicating that the concentrations were no more excessive than good hand jetting when using either diazinon or cyromozine.
 
 

Summary
Considerable evidence was available indicating that wet dipping practices were failing to eradicate lice on sheep and that ineffective wetting was believed to be a major contributory factor. To examine wetting of sheep in plunge and shower dips, a series of experiments were undertaken to investigate both the mechanical and management opportunities which might improve the efficiency and efficacy of wet dipping of sheep for the eradication of the sheep body louse Bovicola ovis. Results indicated that significant improvements could be made to both shower and plunge dipping equipment and practices which would enhance the likelihood of eradication of sheep body lice. The work also identified a number of issues associated with pesticide residues in raw wool, concerns over pesticide concentrations in the dip wash and a number of occupational health and safety issues.
 

Summary:
This paper describes the successful combination of three disparate sources of technology to develop a means of effectively and humanely treating sheep for lice infestation at any stage of the wool growth cycle. Effective treatment is achieved without exceeding target chemical residues in the treated wool.

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