LONG-TERM STUDIES ON THE ECONOMIC-IMPACT OF TICKS ON SANGA CATTLE IN ZAMBIA

Three different tick control policies were tested in groups of traditi onally managed Sanga cattle in the Central Province of Zambia over a p eriod of 3 years. One group was given strategic tick control using 12 pyrethroid acaricide spray applications between the onset and the end of the wet season (October to March). The productivity of this herd wa s compared with that of a group with no tick control and a group under an intensive tick control regimen of spraying every week in the wet s eason and every 2 weeks in the dry season (36 applications per year). The highest output was associated with intensive tick control, followe d by strategic control and then no tick control policies. However, whe n the costs of tick control were taken into account, the strategic tic k control policy produced the best economic result, followed by the in tensive and then the no tick control policies. Neither the strategic n or the intensive tick control policy was sufficient to prevent the tra nsmission of East Coast fever (ECF) infection when this disease was in troduced to the area.