Register      Login
Animal Production Science Animal Production Science Society
Food, fibre and pharmaceuticals from animals
RESEARCH ARTICLE

A regional model of sheep lice management practices for predicting the impact of treatment for lice when no lice are detected

Brian J. Horton A B , Andrew Bailey A and Anna L. Carew A
+ Author Affiliations
- Author Affiliations

A Tasmanian Institute of Agriculture, University of Tasmania, PO Box 46, Kings Meadows, Tas. 7249, Australia.

B Corresponding author. Email: brian.horton@utas.edu.au

Animal Production Science 56(1) 24-32 https://doi.org/10.1071/AN14474
Submitted: 3 April 2014  Accepted: 8 September 2014   Published: 15 January 2015

Abstract

A model of sheep lice management incorporating different assumed levels of lice prevalence in different regions of Australia was used to determine the conditions under which it would be cost-effective to treat sheep for lice at shearing when no lice had been detected. The probability that a flock might be infested was calculated from the probability that the previous treatment had failed to eradicate lice, purchased sheep may have introduced lice, or lice may have entered on straying sheep. The model showed that a flock should be treated if the probability of infestation is greater than 10%. It was projected that acceptance of a risk level greater than 10% would reduce treatment of flocks where no lice were present, thus reducing treatment costs. This higher risk level, however, would increase the proportion of louse-infested flocks that remained untreated, resulting in increased direct lice costs and an increase in the regional prevalence of lice, but little overall change in costs to the sheep industry. The model indicated that treatment of sheep at lower levels of risk (less than 10%) would incur unnecessary costs due to treatment of flocks where no lice were present and would not reduce the regional prevalence of lice more effectively than a 10% intervention level. The model suggested that more accurate methods of detecting lice at shearing would allow higher levels of risk, reduce the use of treatment and hence reduce overall costs associated with managing lice, without increasing the prevalence of lice.

Additional keywords: intervention, lice detection, lice infested, risk.


References

Brightling A (1989) Evaluation of strategies for control of sheep lice (Damalina ovis) with an epidemiological model. Australian Veterinary Journal 66, 55–58.
Evaluation of strategies for control of sheep lice (Damalina ovis) with an epidemiological model.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaL1M3islyksA%3D%3D&md5=9636e9a8e12356f6cd94ef82ce37eeb9CAS | 2712769PubMed |

Campbell AJD, Broekhuizen A, Curtis K, Croker KP, Behrendt R, Thompson AN (2014) A survey of post-weaning mortality of sheep in Australia and its association with farm and management factors. Animal Production Science 54, 783–790.
A survey of post-weaning mortality of sheep in Australia and its association with farm and management factors.Crossref | GoogleScholarGoogle Scholar |

Horton BJ, Carew AL (2014) A comparison of deterministic and stochastic models for predicting the impacts of different sheep body lice (Bovicola ovis) management practices. Animal Production Science
A comparison of deterministic and stochastic models for predicting the impacts of different sheep body lice (Bovicola ovis) management practices.Crossref | GoogleScholarGoogle Scholar |

Horton BJ, Evans DL, James PJ, Campbell NJ (2009) Development of a model based on Bayesian networks to estimate the probability of sheep lice presence at shearing. Animal Production Science 49, 48–55.
Development of a model based on Bayesian networks to estimate the probability of sheep lice presence at shearing.Crossref | GoogleScholarGoogle Scholar |

James PJ (2002) Sheep lice: changing control practices and wool industry implications. Wool Technology and Sheep Breeding 50, 567–573.

James PJ (2010) Issues and advances in the integrated control of sheep lice. Animal Production Science 50, 435–439.
Issues and advances in the integrated control of sheep lice.Crossref | GoogleScholarGoogle Scholar |

James PJ, Riley MJ (2004) The prevalence of lice on sheep and control practices in South Australia. Australian Veterinary Journal 82, 563–568.
The prevalence of lice on sheep and control practices in South Australia.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2crgvFahug%3D%3D&md5=613dc46b6a483cf3e6e429c037e7ff8cCAS | 15478729PubMed |

James PJ, Moon RD, Karlsson LJE (2001) Optimising the sensitivity of sheep inspection for detecting lice. In ‘FLICS: Flystrike and Lice IPM Control Strategies. Launceston, Tasmania’. (Ed. S Champion) pp. 331–340. (Tasmanian Institute of Agricultural Research, University of Tasmania: Launceston)

James PJ, Garrett JA, Moon RD (2002) Sensitivity of two-stage sampling to detect sheep biting lice (Bovicola ovis) in infested flocks. Veterinary Parasitology 103, 157–166.
Sensitivity of two-stage sampling to detect sheep biting lice (Bovicola ovis) in infested flocks.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD38%2FgtFWjsA%3D%3D&md5=928a1b68d3bf128144a2e782b350c23bCAS | 11751010PubMed |

James PJ, Bartholomaeus FW, Karlsson LJE (2007) Temporal relationship between infestation with lice (Bovicola ovis Schrank) and the development of pruritic behaviour and fleece derangement in sheep. Veterinary Parasitology 149, 251–257.
Temporal relationship between infestation with lice (Bovicola ovis Schrank) and the development of pruritic behaviour and fleece derangement in sheep.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD2srpvVyrtg%3D%3D&md5=9028dc5814ee5833db93c69afcf03473CAS | 17900811PubMed |

Levot G (2001) Implications of insecticide resistance for the control of flystrike and lice on sheep. In ‘FLICS Conference. Launceston’. (Ed. S Champion) pp. 127–134. (Tasmanian Institute of Agricultural Research, University of Tasmania: Launceston)

Michalski WP, Young P, Shiell B, Levot G (2001) Development of a lice detection test for ‘on-farm’ use. In ‘FLICS Conference. Launceston, Tasmania’. (Ed. S Champion) pp. 341–345. (Tasmanian Institute of Agricultural Research, University of Tasmania: Launceston)

Morcombe PW, Young GE (1993) Persistence of the sheep and body louse, Bovicola ovis, after treatment. Australian Veterinary Journal 70, 147–150.
Persistence of the sheep and body louse, Bovicola ovis, after treatment.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK3s3mtlylsA%3D%3D&md5=f3457dfb34b1e14eca8ba733b9242a41CAS | 8494525PubMed |

Morcombe PW, Young GE, Ball MD, Dunlop RH (1996) The detection of lice (Bovicola ovis) in mobs of sheep: a comparison of fleece parting, the lamp test and the table locks test. Australian Veterinary Journal 73, 170–173.
The detection of lice (Bovicola ovis) in mobs of sheep: a comparison of fleece parting, the lamp test and the table locks test.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DyaK283mtFaqtw%3D%3D&md5=d7d0d68df26295d8ac60bb1c82fc2526CAS | 8660238PubMed |

Niven DR, Pritchard DA (1985) Effects of control of the sheep body louse (Damalinia ovis) on wool production and quaility. Journal of Experimental Agriculture 25, 27–31.
Effects of control of the sheep body louse (Damalinia ovis) on wool production and quaility.Crossref | GoogleScholarGoogle Scholar |

Popp S, Eppleston J, Watt BR, Mansfield S, Bush RD (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.

Reeve I, Thompson L-J (2005) Integrated parasite management in sheep project: benchmark survey. Report to Australian Wool Innovation, Sydney, NSW.

Sackett D, Holmes P, Abbott K, Jephcott S, Barber M (2006) Assessing the economic cost of endemic disease on the profitability of Australian beef cattle and sheep producers. MLA Report AHW.087. Meat & Livestock Australia, Sydney, NSW.

Wilkinson FC, de Chaneet GC, Beetson BR (1982) Growth of populations of lice, Damalinia ovis, on sheep and their effects on production and processing performance of wool. Veterinary Parasitology 9, 171–177.
Growth of populations of lice, Damalinia ovis, on sheep and their effects on production and processing performance of wool.Crossref | GoogleScholarGoogle Scholar |