The summer drenching program has provided highly effective sheep worm control in Western Australia for many years - but recent research challenges its long term sustainability.
Trial results suggest that in large parts of the State, summer drenching is the main factor leading to the development of drench resistant worms. Alternative programs less likely to lead to drench resistance will require greater monitoring of worm burdens and panning pasture moves.
"Re-thinking the summer drenching program,"
Journal of the Department of Agriculture, Western Australia, Series 4: Vol. 42
, Article 3.
Available at: http://researchlibrary.agric.wa.gov.au/journal_agriculture4/vol42/iss1/3