Factors associated with adaptation and performance of trypanotolerant Orma boran bulls in Kajiado District, Kenya

Abstract

Adaptation of 14 trypanotolerant OB bulls disseminated to Kajiado District for livestock improvement was assessed. The bulls were monitored for body weight changes, PCV, and prevalence of trypanosomosis, anaplasmosis, babesiosis and ECF infections monthly from November 2002 to December 2004. Morbidity status, retention time and mortality rate were used as the measures of outcome indicating bulls’ adaptation. Data was analyzed using descriptive statistics, association tests and logistic regression. Only 29% of the bulls completed the anticipated 2 year retention period. Mean duration of stay was 20.8 months with significant difference between low and high tsetse density areas. Mean PCV was 27% and was significantly lower in trypanosomosis infected bulls. Prevalence of infections was trypanosomosis 20.3%, ECF 9%, anaplasmosis 46% and babesiosis 7%, which were associated with animal level, management and geographic factors. Although trypanosomosis infection had the most significant effect on bulls’ health, survival and productivity, perhaps a true case of trypanotolerance was demonstrated by one bull that was never detected with a trypanosome infection suggesting that the breed could be used for effective utilization of tsetse fly infested lands. Pastoralists’ apathy, severe drought, high prevalence of infections and mortality were challenges faced by adoption of trypanotolerance technology.