Petros Beyene (Professor)Jobre Yilma (PhD)Asrat Michael2018-07-052023-11-082018-07-052023-11-082004-12http://etd.aau.edu.et/handle/123456789/6756An attempt was made to determine the infection prevalence of ovine fasciolosis in small-scale irrigation schemes in three agro-ecologic zones in the Upper Awash River Basin from November 2003 to October 2004. In addition, a survey was conducted to determine snail fauna and habitat (water temperature and pH) in the same locations. Furthermore, the effects of a one- and twostrategic triclabendazole (anthelmintic) treatments on some indicator parameters and associated economic returns were evaluated. Statistical comparisons, using Chi-square and ANOVA statistics, were made to determine the presence of difference in prevalence rates between irrigated and nonirrigated areas, agro-ecologic zones, seasons, age and sex. Feacal samples of 1296 sheep were examined and 729 (56.3%) were found positive for fasciolosis. The infection prevalence in the highlands (62.9%) was significantly higher (p<0.05) than both midaltitude (51%) and lowlands (52%). No statistically significant difference (p>0.05) was depicted between fasciolosis infection prevalence in mid-altitude and lowland study sites, on the one hand, and between sexes as well as age categories, on the other hand. The overall wet season prevalence (59.2%) was significantly higher (p<0.05) than the dry season prevalence (53.6%). Similarly, prevalence in irrigated sites (60.8%) was significantly higher (p<0.05) than non-irrigated lands (50.4%). Closer analysis of results, however, indicated that there was no statistically significant difference (p>0.05) in prevalence rates between irrigated and non-irrigated study sites; as well as between the dry and wet seasons in the highland sites. On the other hand, irrigation has significantly increased (p<0.05) the prevalence of ovine fasciolosis in mid-altitude during the dry season and in lowlands both during the dry and wet seasons. In the present study, small-scale irrigation schemes were shown to heavily influence fasciolosis prevalence in mid-altitude and lowland areas. These findings warrants that special schemes need to be instituted for fasciolosis and other water-borne animal, and human diseases in agricultural development efforts involving irrigation agricultural in these environments. Of the two recognized snails serving as intermediate hosts for Fasciola spp., L. truncatula was found in all agro-ecological sites, while L. natalensis was only encountered in the lowland areas. No marked difference was observed in water pH (7.03-8.58) and temperature (17.2oC – 26.8 oC)) in all sampled snail habitats across the study areas. This indicated that snail inhabited within the tolerable bionomic ranges despite their population size difference along with the agro-ecologic zones where they were found. The trial on strategic anthelmintic treatment revealed that twice triclabendazole treatments are effective in markedly decreasing feacal egg output (0.03±1.32), improving packed cell volume (6.50±1.28), body weight gain (4.10±0.76) and body condition scores (0.57±0.09) than a one-time treatment 0.35±1.55, 3.56±1.16, 0.90±0.73 and 0.17±0.08, feacal egg output, packed cell volume, body weight gain and body condition scores, respectively. The economic return from one and twice strategic triclabendazole treatments was 5.24 and 26.16 birr/animal/year. Untreated control animals showed negative weight gains, hence, no monetary return over the study year. The non-monitory benefits that smallholder farmers obtain from strategic anthelmentic treatment interventions were discussed. Future studies to investigate the long-term effects of such strategic treatments intervention in the highlands and replication of similar trials in mid-altitude and lowland sites are recommended. Keywords: - Fasciolosis, Infection Prevalence, Sheep, small-scale irrigation, strategic treatment, Upper Awash River Basin, Ethiopia.enFasciolosisInfection PrevalenceSheepsmall-scale irrigationstrategic treatmentUpper Awash River BasinEthiopiaThesis