Prevalence of ticks on local and crossbred cattle in and around Asella town, southeast Ethiopia

Abstract

The prevalence of bovine tick species in and around Asella town was studied over a period of eight months from October 2007 to May 2008. Adult ticks were collected from 384 local and crossbred cattle which were kept under extensive management system and at different agro-ecological zones. A total of 6298 adult ticks were collected from half body part of cattle, and were identified to genera and species level. Five tick species of four genera were identified, in which two species belong to genus Amblyomma, and one species each in the genus Boophilus, Rhipicephalus and Hyalomma. Of all the total ticks collected, Amblyomma, Rhipicephalus, Boophilus and Hyalomma constituted 60.1%, 22%, 15.4% and 2.5%, respectively. The tick species encountered were A. variegatum (48.2%), Rhipicephalus evertsi-evertsi (22%), Boophilus decolaratus (15.4%), A. cohaerence (11.9%) and Hyalomma marginatum rufipes (2.5%). The burden of ticks on cattle had statistically significant difference (P<0.05) between local (mean=13.1 tick/head) and crossbreed (mean=21.4 tick/head) cattle, and between cattle found in highland (mean=13.1 tick/head) and midland (mean=21 tick/head) areas of the region. The results indicated that the favorable predilection sites of Amblyomma species are ventral body part and hoof. B. decolaratus prefer dewlap, head and back. Adult R. evertsi-evertsi and H. marginatum rufipes had a strong predilection for tail as well as ano-vulva areas. The sex ratios of all tick species identified were skewed towards male except for B. decolaratus. Further studies on factors affecting tick burden and tick control strategies are recommended.

Keywords: Ethiopia, Asella, cattle tick, predilection site, highland, midland