Abstract

The study was conducted in Birbir valley of Oromia Regional State, Western Ethiopia from November 2009 to July 2010 to determine the prevalence and seasonal incidence of bovine trypanosomosis. Blood samples from 2219 randomly selected cattle of both sex and different age groups were collected and examined with conventional hematological and parasitological techniques. Out of the total examined animals, 195 (8.78%) cattle were infected with trypanosomes. Most of the infections were due toTrypanosoma congolense (65.6%) followed by Trypanosoma vivax (33.8%) and the rest were mixed infections of T. congolense and T. vivax (0.51%). There was no statistically significant difference (P>0.05) in infection between male and female, young and adult animals and altitude levels. However, higher proportion of the infection was detected in adult male animals, during wet season and in lowland areas; 9.03, 10.33, 10.11% respectively. Mean packed cell volume (PCV) value of parasitaemic and a parasitaemic animals was not significantly (P>0.05) different. The average seasonal incidence of trypanosome was 21.66, 10, 13.79 and 17.24% during the late rainy, dry, early and wet seasons, respectively. The relative higher incidence rate was observed during the wet seasons of the year. The study revealed that trypanosomosis is the main constraint to livestock production and agricultural activity in Birbir valley, Western Ethiopia. Hence, implementation of integrated tsetse and trypanosome control measures will save greater economic loss of the region in particular and the country in general.

Key words: Cattle, epidemiology, T. congolense, T. vivax, trypanosomosis, Western Ethiopia.