Cattle can form a natural immunity for life to tick fever if they are exposed to all three tick fever organisms before 9 months of age. Additionally, a temporary immunity is passed from a mother with immunity to her calf via colostrum in the mother's milk.
The three tick fevers are known as Babesia bovis, Babesia bigeminia and Babesia divergens. Although it only takes one tick bite to pass on any one of these three parasites, it is not guaranteed that the tick is an infected one. If a farmer relies on natural tick exposure to make calves immune, the herd needs to be exposed to thousands of ticks to ensure the parasites are transmitted. If tick populations are smaller due to dry seasons or tick control operations, natural exposure may prove to be problematic.