Veterinary Clinical Medicine

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Browsing Veterinary Clinical Medicine by Author "Ayalew, Tegaye"

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    Studies on Ixodid Cattle Ticks From Some Selected Sites of Central Oromia Regional State: Species Composition, Seasonal Variation and Control Practices
    (Debre Zeit, 2009-06) Ayalew, Tegaye; Kumsa, Bersissa PhD
    A study was conducted to determine the distribution, prevalence and seasonal variation of tick species on cattle in central Oromia regional State using cross-sectional and longitudinal study methods. During the study period a total of 10,085 adult ixodid ticks were collected from a half body regions of 918 cattle in three agro-ecological zones during wet and dry seasons .Of these collected ticks 5542 were males whereas 4543 were females. Results of the study showed that an overall prevalence of 87.1 % tick infestation on cattle was recorded. In the study four genera and seven species of ixodid ticks were identified during the wet period whereas similar number of genera but six species of ixodid ticks were identified during the dry periods. Amblyomma ,Boophilus Rhipicephalus and Hyalomma tick genera were identified during the two seasons. Five different species of ticks were identified from the highland altitude. Significantly (p<0.05) higher proportion of B.decoloratus (88.2%) was identified during the wet season. But Hy. truncatum (1.5%) was identified with least proportion during the wet period. Rhe. evertsi (50.8%) was the most abundant during the dry period whereas Hy.marginatum rufipes (5%) was with smallest proportion during the same season. In midland altitudes a total of six species of ticks were identified. Significantly (p<0.05) higher proportion of A.variegatum (75%) than the other species was recorded during the wet season. But Rhpulchelus (.4%) was collected at the lowest proportion during the wet season. Rhe.evertsi (49.6%) was the most abundant tick species during the dry season whereas Hy.truncatum (0.6%) was with lowest proportion during the dry season. In lowland altitude lower proportion of ticks were collected. A total of seven species of ticks in the wet and six in the dry season were identified. Significantly (p<0.05) higher proportion of Hy.truncatum (85.9%) was recorded during the wet season whereas Rhpulchelus (1.5%) was identified with the lowest proportion .Rhevertsi evertsi (68.6%) was the most abundant tick species during the dry season .But B.decoloratus was with the lowest proportion during the same dry season. Results of the longitudinal studies revealed that highest mean total tick burden was recorded during the early rain season than the dry season from the end of March to April. And the lowest infestation rate was recorded during early dry season and the late dry season during December and February, respectively. The overall, tick count across seasons showed significant variation at p<0.05 (F=114 & p=O.OOO). A questionnaire survey on the aspects of tick control has revealed that the majority of farmers have sufficient knowledge about the economic significance of ticks. Diazinon 60% and cypermethrin were the commonly used acaricides with a frequency of 1 to 3 times per year during the peak season of tick infestation. A. variegatum and B.decoloratus, the most prevalent and dominant tick species in mid and highland altitudes, respectively seems more adapted than the other species to environmental factors prevailing in the areas. Thus, strategic application of acaricides especially at the beginning and end of wet months might minimize the burden of ticks on the cattle of the study areas.