Prof. Getachew AbebeTERZU, DAYA2020-06-112023-11-082020-06-112023-11-082004http://etd.aau.edu.et/handle/123456789/21522A seasonal dynamics of tsetse and trypanosomosis study was carried out in selected sites of Southern Nation, Nationalities and Peoples Regional State (SNNPRS). The purposes of the study were to determine the seasonal apparent density of tsetse and prevalence of trypanosomosis, to identify tsetse and trypanosome species and to assess the curative/prophylactic effect of isometamidium chloride in selected sites (Badaye and Gadala PAs) of SNNPRS. Community members (n = 80) were interviewed using prepared questionnaire format. Cross sectional studies were carried out from October to April during late wet (October), early dry (December), late dry (February) and early wet (April) seasons in villages of Badaye and Gadala PAs. Samples for parasitological and entomological studies were collected from one villages of Badaye and two villages of Gadala PAs per season. Biconical traps used for entomological survey were deployed at grazing and watering points of animals in the villages of Badaye and Gadala PAs. For parasitological study, a total of 1,509 blood samples were collected from randomly selected cattle within four seasons. For longitudinal field study, parasitaemic Zebu cattle (n = 64) were selected for isometamidium chloride block treatment. Parasitaemic cattle with 39 (60.9%) T. congolense, 24 (37.5%) T. vivax and 1 (1.6%) mixed (T. congolense and T. vivax) infections were treated with prophylactic dose of (1mg/kg bw) isometamidium chloride at day 0 and monitored at day 15, 30, 60 and 90. The result of questionnaire revealed that 97.5% of respondents depend on smugglers for trypanocidal drugs and sick animals were treated by smugglers and owners with high treatment frequency (6 times per cattle per year). The entomological finding revealed three tsetse species namely, G. m. submorsitans, G. fuscipes and G. pallidipes at Badaye and Gadala PAs, respectively. Higher catches of G. pallidipes were registered during late wet (October) and early dry (December) seasons in comparison with late dry (February) and early wet (April) seasons. There was a significant difference (p < 0.05) in mean catches of G. pallidipes between seasons. The apparent density of G. pallidipes was positively correlated (r = 0.5176) with prevalence of trypanosome infection.The overall trypanosome infection prevalence in cattle was 15.77%. During late wet and early dry seasons, the prevalence of trypanosomosis was high (21.5%) and during late dry and early wet seasons low (10.8%). During early wet season, significantly (p < 0.05) higher prevalence was registered at village of Badaye PA (15.38%) than the villages of Gadala PA (8.51%). There was a significant difference (p < 0.001) in trypanosome infection prevalence between seasons. Giemsa stained blood smear examination revealed the presence of T. congolense and T. vivax in the study area. T. congolense was dominant species and accounted for 63.4% in overall infections. The overall mean PCV value was 24.02%. The mean PCV values of different seasons were negatively correlated (r = -0.3112) with the prevalence of trypanosomosis of corresponding seasons. There was a statistically significant difference (p < 0.0001) between mean PCV values of parasitaemic and aparasitaemic cattle tested during different seasons. There was a significant difference (p < 0.001) in trypanosome infections between different age groups of cattle. In longitudinal field study, parasitaemia was demonstrated in 17 out of 64 cattle (26.56%) with in 15 days, 19 out of 64 cattle (29.7%) with in 30 days, 41 out of 64 cattle (64.06%) with in 60 days and 44 out of 64 (68.75%) with in 90 days post treatment of 1mg/kg bw isometamidium chloride. T. congolense was accounted for 85.5%, 89.5%, 78% and 79.5% of infections within 15, 30, 60 and 90 days post treatment of isometamidium chloride, respectively. Based on these results it is concluded that trypanosomosis is the major constraint of livestock production in the study sites.enSeasonTsetse flyTrypanosomosisTrypanosomesThesis