Effect of trypanosomosis and tick borne diseases on productivity of Orma / Zebu cattle in an (ASAL) area of south western Kenya

Abstract

Trypanosomosis and tick-borne diseases (TBD’s) have a profound impact on the livelihoods of agro-pastoralists in the ASAL areas of Kenya whose transhumance nature exposes livestock to tsetse-infested areas and also new ground may be sources of parasites. Both diseases are endemic and cause suboptimal production, which is enhanced in presence of endoparasites and nutritional stress. Trypanosomosis infected animals have pronounced immunosuppression and easily succumb to TBD’s even in presence of endemic stability and perhaps trypanotolerant animals will show minimal loss in production. A trial was conducted in trypanosomosis endemic foci to assess productivity of three hundred Orma zebu (OZ) (trypanotolerant Orma boran x Maasai zebu) and Sahiwal zebu (SZ) (susceptible Sahiwal x Maasai zebu) crosses, which were monitored monthly from birth to 18 months for prevalence of trypanosomosis and TBDs, and body weight changes. Diagnosis was based on parasitology and serology. Growth rate and disease prevalence were used as outcome measures of productivity. Factors associated with these outcome variables were assessed using multiple regression [Proc Reg, SAS version 9.1, SAS Institute Inc., Cary, NC, USA] and logistic regression [Proc Logistic] fitted at 95% confidence level. Daily weight gain for the O/Z and S/Z were 0.209 g/d and 0.212 g/d respectively and comparable. Prevalence of trypanosomosis, TBD and EPG counts were 1.9% and 2.5%; 59% and 62%; 48 and 42 in the O/Z and S/Z respectively. Factors significantly associated with disease distribution were season and age of calves. Enhanced trypanotolerance in O/Z crosses can be utilized for effective reclamation of tsetseinfested lands.