Strategic control of ticks with synthetic pyrethroids in Theileria parva endemic areas in Tanzania increases calf growth and survival rates

The effect of tick control by strategic dipping in synthetic pyrethroids on growth and survival rates of calves in Eastern Tanzania where Theileria parva and other tick borne infections (babesiosis, anaplasmosis and ehrlichiosis) are endemic was measured. One day to five months old Tanganyika short horn zebu ( Bos indicus ) maintained on pastures were divided in two groups; group 1 (n=1340) were non treated control and group 2 (n=17920) were dipped regularly in pyrethroid acaricides at 14 day intervals. Body weights, mortality and survival rates of calves were determined by portable weighbridge and monitoring. Mean weights of group 1 calves at 1, 2, 3, 4 and 5 months of age were 28.0±1.09, 46.5±2.39, 53.3±2.01, 66.4±2.83 and 83.1±3.89 Kg respectively, growth rate on average being 11.1 Kg/month. Mean body weights of group 2 calves at same ages were 28.0±0.97, 46.0±0.24, 73.0±2.18, 96.7±2.60 and 101.7±2.01 Kg respectively, average growth rate being 14.8 Kg/month. Mortality rate in group 1 calves was 37.5% compared to 2.96% in group 2 calves. It is concluded that tick control increases calf growth and survival rates. Keywords : East cost fever, Theileria parva , endemic stability, tick acaricide Tanzania Vet Journal Vol. 25 (2) 2008: pp. 88-95