HOST-RESISTANCE TO TICKS (ACARI, IXODIDAE) IN DIFFERENT BREEDS OF CATTLE AT BAKO, ETHIOPIA

European cattle breeds are being introduced into Ethiopia in an effort to improve the productivity of indigenous breeds. The Ethiopian cattl e breeds Horro and Boran were compared for tick burdens with heir cros ses with Friesian, Jersey and Simmental. Horro animals had the lowest tick burndens and the Horro x Fiesian the highest. Adaptation to their environment and long-term natural selection for tick resistance in Ho rro cattle is the most likely explanation. Repeatability of tick burde ns in all animals considered as one herd were only statistically signi ficant for Boophilus decoloratus, the most abundant tick species. Stat istically significant correlations between burdens of female B. decolo ratus, Amblyomma cohaerens and Rhipicephalus praetextatus were observe d and the addition of the males resulted in all inter-species correlat ions becoming significant. Care should be taken when crossing Ethiopia n with more productive European cattle breeds in order not to lower th eir tick and disease resistance.