A preliminary survey of gastrointestinal and haemoparasites of beef cattle in the tropical livestock farming system in Nan Province, northern Thailand.

Parasitism is a primary cause of production losses in most cattle-producing countries of the world, including Thailand. A cross-sectional study was designed to determine baseline data on the prevalence of gastrointestinal and haemoparasites of beef cattle in Nan Province, northern Thailand and to investigate the factors associated with the prevalence of parasitic infections. A total of 207 faecal and 162 blood samples were collected during the summer of 2005. The basic data of management were recorded, including the number of animals on the farm or in the village, major animal health problems, deworming programme and veterinary service. The overall prevalence of gastrointestinal parasitic infections was 61% (126/207). The most common helminth infections in this study were rumen flukes 28% (58), followed by strongyles 27% (55), and the rest were due to Strongyloides 1% (2) and Trichuris 1% (2). The common protozoan infections were Buxtonella cysts 2% (5) and coccidia oocysts 2% (4). Of the 162 blood samples examined, 50% (81) contained Theileria sp., 2% (4) trypanosome, and 1% (1) microfilariae. The high rate of parasitic infections in these areas might be related to the poor management by the farmers, such as sharing the same grazing pasture.