A Survey of Theileria sergenti Infection, Tick and Horse Fly Infestation in 304 Herds of Grazing Holstein Heifers in Japan

Abstract

We conducted a questionnaire survey of 304 herds of grazing Holstein heifers in Japan. Using the results of the survey, we investigated Theileria sergenti infection, tick infestation and horse fly infestation in associated with potential risk factors such as environmental and management conditions. Theileria sergenti infection was more common in the southern part of Japan and herds with drug and acaricide usage were associated with T. sergenti infection. Herds with tick infestation was highly associated with T. sergenti infestation. Horse flies were more commonly observed in prefectures other than in Hokkaido. Proper preventive strategy for these parasite infestation is strongly required.