Ruminant nematode larvae of grazing cattle in Sorayama and Tawara [Tottori Japan] cattle raising pastures

We investigated the survival of gastrointestinal nematodes's infective larvae in the raising pasture. The quantity of the larvae increased from March to August and deceased from September gradually. It is considered that this is a seasonal variation. The survival of the larvae has a close relation to the climatic factor in the raising pasture, and so it is conjectured that the gastrointestinal nematodes of grazing cattle reinfect in the raising pasture. To exterminate the larvae in the raising pasture it is necessary to prevent the infection of the grazing cattle's gastrointestinal nematodes