Abstract
In Ethiopia, livestock are an integral part of farming systems, and importance sources of high quality protein (meat, milk and eggs) as well as they are contributing to the economic welfare of the people. Bovine trypanosomosis is a parasitic disease causing serious economic impact on livestock productivity and agricultural development. A repeated cross-sectional design was employed to estimate the seasonal prevalence of trypanosome infection and to assess Glossina spp. apparent density in Zala district, Gofa zone. A total of 560 cattle (280 in each season) were examined for trypanosome by using buffy coat technique. For the entomological survey, 80 NGU traps, odour-baited with acetone, were deployed in watering and grazing areas that is where the animals and vector are believed to have frequent contact. The overall prevalence of trypanosome infection in cattle was 7.0% (95% CI = 5.1-9.4). The dry and wet season trypanosome infection were 4.3% (95% CI = 2.4-7.4) and 9.6% (95% CI = 6.7-13.7), respectively. The prevalence of cattle trypanosome infection was significantly higher during wet season (OR = 2.38, p < 0.05), in black and black-spotted coat color (OR = 4.61, p < 0.05) and poor body conditioned (OR = 4.55, p < 0.05) animals. Both in dry and wet seasons two species of Trypanosoma were circulating in the area: Trypanosoma congolense (87.2%) and Trypanosoma vivax (12.8%). The mean PCV value of infected cattle (20.89 ± 4.04) was significantly lower than in non-infected animals (22.9 ± 6.32%). A total of 564 flies were caught, and 56.9% was Glossina spp. and 43.1% was other biting flies. Glossina pallidipes was the only species observed, and moreover, two other genera of biting fly (i.e. Stomoxys spp. and Tabanus spp.). The overall apparent density of Glossina pallidipes was 1.38 F/T/D, and it was 1.78 F/T/D and 0.99 F/T/D, in wet and dry season, respectively. The observed prevalence of trypanosome infection, and Glossina pallidipes apparent density could be a potential threat to animal health and productivity. So, the recorded prevalence was high, and it suggests that the need for the development of strategy for vector and the parasites control.