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RESEARCH ARTICLE
Contents Vol 45(9)

Changes in diazinon concentrations during shower and plunge dipping of Merino sheep

R. D. Lund A , G. W. Levot B D and R. Black C
+ Author Affiliations
- Author Affiliations

A Agricultural Research Centre, NSW Department of Primary Industries, PMB 19, Trangie, NSW 2833, Australia.

B Elizabeth Macarthur Agricultural Institute, NSW Department of Primary Industries, PMB 8, Camden, NSW 2570, Australia.

C Wollongbar Agricultural Institute, NSW Department of Primary Industries, PMB, Wollongbar, NSW 2477, Australia.

D Corresponding author. Email: garry.levot@dpi.nsw.gov.au

Australian Journal of Experimental Agriculture 45(9) 1139-1145 https://doi.org/10.1071/EA03084
Submitted: 26 April 2003  Accepted: 24 June 2004   Published: 10 October 2005

Abstract

The rate of removal of diazinon from solution (stripping) during dipping of adult short wool Merino sheep was similar in a standard and modified Buzacott 60R shower dip. During 12 min showering, dip concentration fell from about 100 mg/L to about 20 mg/L. Addition of insecticide concentrate (reinforcement) and sufficient fresh solution to re-establish original sump volume (topping up or replenishment) at this point restored dip concentration but was contrary to product label instructions. Adherence to the label directions to reinforce and top up after the sump was depleted by 25% (after 2 pens of sheep in the case of the standard dip) caused dip concentration to drop below the limit of quantification (10 mg/L). Similarly, current directions for continuous replenishment (commonly referred to as constant replenishment) shower dipping failed to offset diazinon stripping. Continuous replenishment plunge dipping with diazinon for the control of lice on sheep is an off-label use of the product; however, we demonstrated that a working concentration of about 100 mg diazinon /L (the nominal rate for lice control) was maintained in a 5000 L non-draining dip if charged and replenished at 200 mg diazinon/L. By maintaining 100 mg/L, this regimen was more likely to eradicate lice from sheep. This work also identified, by calculation, large and potentially significant variations in the dose of diazinon applied per sheep due to the application method, reinforcement practice and whether the sheep were treated early or late in the dipping sequence.

Additional keywords: shower dip, plunge dip, dip wash, constant replenishment.


References


Ashton J, Savage G (2001) Integrating ‘Best Practice’ chemical use and residue management with regulation — a challenge for both the wool industry and the NRA. In ‘Proceedings FLICS’. pp. 31–39. (Aust Wool Innovation Pty. Ltd. and Department of Primary Industries, Water and Environment: Launceston, Tas.)

Chandler DS, Sherwood N (1999) Introduction to Nufarm Diprite. Prescription dosing with stripping dips. Addendum to ‘Proceedings of the Australian Sheep Veterinary Society’. (The Australian Sheep Veterinary Society: Hobart, Tas.)

Graham NPH, Sinclair AN, Cavey WA (1959) Control of insecticide exhaustion in sheep showers. Australian Veterinary Journal 35, 99–100. open url image1

Levot GW (1994) A survey of organophosphate susceptibility in populations of Bovicola ovis (Schrank)(Phthiraptera: Trichodectidae). Journal of the Australian Entomological Society 33, 31–34. open url image1

Levot GW, Johnson PW, Hughes PB, Powis KJ, Boray JC, Dawson KL (1995) Pyrethroid resistance in Australian field populations of the sheep body louse, Bovicola (Damalinia) ovis. Medical and Veterinary Entomology 9, 59–65.
| PubMed |
open url image1

Lund RD, Johnson PW, Gould NS, Van De Ven RJ (1997) ‘DAN 197 Improved design and use of dipping equipment for sheep lice eradication.’ Final report to IWS. (NSW Agriculture: Orange)

Robinson PW, Reid TC, Joyce NI, Boul HL (1998) Meeting market and consumer requirements in wool production. Wool Technology and Sheep Breeding 46, 172–187. open url image1

Sherwood N, Watts T, Allan C, Chandler D (1999) Variation of pesticide concentration in sheep dips operated according to traditional and revised methods. Australian Veterinary Journal 77, 384–387.
| PubMed |
open url image1

Watts JE (1979) Body strike in sheep. In ‘National symposium on the sheep blowfly and flystrike in sheep’. pp. 113–119. (NSW Department of Agriculture with the Australian Wool Corporation: Sydney)