Résumé
Abortion among dairy cows is a major problem affecting livestock development in Thailand and is caused by many diseases. Trypanosomosis is one of the diseases causing immunosuppression in cattle. The objective of this study was to investigate the prevalence of Trypanosoma evansi infections evansi infections among dairy cows in the central region of Thailand. The study was performed by collecting of 544 blood samples from 105 private farms in 5 major dairy cow provinces (Kanchanaburi, Ratchaburi, Nakhon Prathom, Saraburi, and Lopburi). The overall prevalence of T. evansi infections among dairy cows was 8.1 percent (44/544) and herd prevalence was 19.2 percent (20/105). The highest individual prevalence was found in Saraburi province (17.4 percent, 21/121) but the highest number of herd infection was in Nakhon Prathom province (30 percent, 6/20). The parity four and four plus were 3.7 time more likely to be infected than heifer and parity one (p LT 0.034). The larger herd (40 milking cows) was found 5.4 time more infected than small herd (p LT 0.021). The result found that trypanosome infection might be the predisposing cause of other diseases and the barrier to increase productivity in dairy herds.