FACTORS INFLUENCING PREVALENCE OF TRYPANOSOMOSIS IN ORMA BORAN (TRYPANOTOLERANT) AND TESO ZEBU (TRYPANOSUSCEPTIBLE) CROSSES IN TESO DISTRICT, WESTERN KENYA

摘要

The objective of this study was to determine factors associated with occurrence of trypanosomosis in the first generation (F1 ) crossbreds between trypanotolerant Orma Boran and trypanosusceptible Teso zebu cattle in a trypanosomosis endemic area in Teso District, western Kenya. The offspring were screened for trypanosomosis and other haemoparasites using parasitological methods. Packed cell volume (PCV), body weights and tsetse density (FTD) were also determined. Factors considered in the analysis included sex, age, body weight and season of the year. Generalized linear mixed models were used for multivariable analysis to account for clustering of observations at the animal level and estimate outcome variance parameters. The overall trypanosomosisprevalence was 2.3% (n=477) probably corresponding to low FTD in the area (<1 fly/trap/day). The risk of trypanosomosis infection was higher in dry than wet season (OR = 5.4) and in older than younger offspring (OR =1.1). The variance parameters obtainedindicated that variation of trypanosomosis prevalence lay only at the animal level. Intercurrent haemoparasites detected included Anaplasma marginale, Theileria and Babesia species. The results suggest that the Orma-Teso crosses experience increased trypanosomosis incidence in the dry season. This therefore requires targeted use of prophylactic drugs particularly in the dry season.