Sheep production os one of Western Australia's most important agricultural industries. However, it is faced with the serious threat of sheep worm populations becoming increasingly resistant to the available drenches.
Although it's not a 'quick fix' solution, part of the long term answer may be selection for sheep with greater resistance to worms.
Karlsson, John; Greeff, Johan; and Harris, Julia
"Breeding sheep for worm resistance,"
Journal of the Department of Agriculture, Western Australia, Series 4: Vol. 36
, Article 6.
Available at: http://researchlibrary.agric.wa.gov.au/journal_agriculture4/vol36/iss2/6