SUSCEPTIBILITY TO TRYPANOSOMOSIS OF 3 BOS-INDICUS CATTLE BREEDS IN AREAS OF DIFFERING TSETSE-FLY CHALLENGE

Studies to assess the differences in susceptibility to trypanosomosis among Bos indicus cattle breeds (Maasai Zebu, Orma Boran and Galana Bo ran) were conducted under conditions of varying tsetse fly challenge a t the Nguruman escarpment in south-western Kenya, for a period of 1 ye ar. It was found that under tsetse challenge quantified as high, Maasa i Zebu and Orma Boran were less susceptible than Galana Boran to trypa nosome infections, as judged by the significantly lower incidence of i nfection, development of less severe anaemia, fewer requirements for t rypanocidal drug treatments, higher growth rates and fewer mortalities . In the area where tsetse challenge was considered low as a result of a tsetse fly control operation using odour-baited traps, only the Maa sai Zebu and Orma Boran were compared. No significant differences in t he incidence of infection, degree of anaemia or growth rates were obse rved between the two breeds, but all were significantly different from their counterparts in the high tsetse challenge area. These results s uggest that there is variation in resistance to trypanosomosis among B os indicus cattle breeds that could be exploited as part of the integr ated trypanosomosis control programmes in East Africa. (C) 1998 Elsevi er Science B.V. All rights reserved.