Investigating the effect of gastrointestinal nematodiasis in Merino sheep on the Northern Tablelands of New South Wales and implications for Integrated Parasite Management

Abstract

On the Northern Tablelands of NSW, gastrointestinal nematodiasis imposes significant constraints to sheep production. The overall aim of this thesis was to quantify this production loss and evaluate the extent to which it can be ameliorated by integrated parasite management approaches. The general hypothesis tested in this work was that gastrointestinal nematode infection (i.e. worms) present on commercial sheep properties in the Northern Tablelands of NSW induces significant production loss and that worm control utilising Integrated Parasite Management in Sheep (IPM) would reduce this loss and the overall economic impact of worms. ... This research has quantified the biological and economic impact of worms on commercial farms on the Northern Tablelands of NSW in the largest and most comprehensive study of its kind to date. It has shown it to be higher than previous estimates which is primarily due to increased commodity prices. The work has also clearly demonstrated the benefits of Integrated Parasite Management in Sheep in reducing both worm-induced mortality and the overall economic impact of gastrointestinal nematode infection. It is hoped that the information presented in this thesis will ultimately support an increased adoption by industry of sustainable worm control programs.