The effect of Amblyomma variegatum on liveweight gain of cattle in Zambia.

The effect of the tick Amblyomma variegatum Fabricius on liveweight gain (LWG) on yearling cattle over 16 weeks was evaluated under quasi-natural conditions. Early in the exposure period when animals may have been in a state of suppressed metabolism, the effect of tick feeding on LWG was negligible. Overall, however, the difference in LWG between tick-free and tick-infested groups of cattle was 4.95 kg after 16 weeks. This difference between the groups was used to estimate a lower LWG of 48-63 g due to each engorging female tick.