Occurrence of Gastrointestinal Nematodes and Dictyocaulus viviparus in Grazing Calves on a Pasture in Yamaguchi Prefecture

Abstract

In a pasture 50 rearing Holstein calves were grazed in summer and spring over a period from June, 1983, to December, 1984. They were examined by a modification of the Wisconsin method and the method of flotation in the centrifugation tube. As a result, Cooperia oncophora, Cooperia punctata, Dictyocaulus viviparus, Mecistocirrus digitatus, Nematodirus sp., Ostertagia ostertagi, Strongyloides papillosus, and Trichuris discolor were detected from them. The infection of each species was mild.
Some of the calves were administered with an anthelmintic. The incidence of Japanese Theileriasis and gain in body weight were compared between these calves and the other untreated ones. The parasitic infection exerted no significant influence upon the incidence, but the treatment seemed to have improved the gain in body weight.