New approaches to sheep parasite control - the potential for individual sheep management

Abstract

Sheep worm control has become significantly less effective throughout Australia due to the increasing severity of anthelmintic resistance. Integrated parasite management recommendations aim to minimise the need for drenching, through the use of new management programs and non-chemical worm control such as breeding worm resistant sheep. New approaches through the Australian Sheep Industry Cooperative Research Centre include novel tests for worm burdens, biological control methods, and nutritional strategies to maximise the immune response. In the shorter term, an effective strategy to reduce the development of resistance is to ensure the survival of a worm population not exposed to drenches, so that resistant worms are diluted and do not increase at an unmanageable rate. The marked variation between and within flocks in the size of worm burdens, and the tolerance of their effects, provides an opportunity to selectively target anthelmintic treatments, hence reducing the selection pressure for resistance of worms to anthelmintics. The efficiency of individual sheep and flock management will be enhanced by the use of electronic sheep identification and measurement.