Costs of major parasites to the Australian livestock industries.

A cost-benefit model is developed to estimate the costs of major parasites to Australian livestock industries and to evaluate the benefits from improving parasite management. The model disaggregates the Australian livestock industries into agro-climatic regions and various stock classes to estimate the total treatment and production loss costs of major parasites. Experimental trials and a computer simulation model are used to estimate the productivity of livestock under different treatment regimes. Using the model, the economic costs inflicted by cattle ticks, sheep gastrointestinal worms, sheep lice and sheep blowflies are discussed and the farm profitability resulting from improved sheep roundworm management is assessed.