Diarrhoea due to trichostrongylid larvae in Merino sheep - repeatability and differences between bloodlines

摘要

Accumulation of faeces around the breech (dag) of Merino ewes occurs during winter and spring in the high rainfall areas (> 550 mm rainfall per annum) of south-eastern Australia, even on farms where strategic worm control programs are effective. A necessary cause of this syndrome has been shown to be the ingestion of trichostrongylid larvae (Larsen et al 1994). Treatment with a controlled-release capsule containing an anthelmintic almost eliminates the occurrence of moderate and severe dag although this strategy may not be profitable for wool producers (Larsen et al 1995).