Field Observations on the Epidemiology of Parasitic Gastro-enteritis in Calves

Abstract

A field study of the epidemiology of parasitic gastro-enteritis in calves has shown that both in Northumberland and Durham and in Devonshire, infestations on the pasture fall to a low level by the end of April. If the pasture is contaminated by calves turned out at this time, the infestation on the herbage is unlikely to rise before July. In the south-west, however, contamination before mid-May can result in the appearance of infective larvae on the herbage in the second half of June. Very heavy herbage infestations were frequently seen in the winter. The hazards of turning calves out early in the spring are discussed and some precautionary measures suggested.