T- and B-lymphoid cell population in calves immunized against Theileria annulata.

Distribution of T- and B-lymphoid cells in peripheral blood, lymph node, spleen and bone marrow of normal healthy calves and valves immunized against Theileria annulata followed by challenge on Day 50 post-immunization were studied by rosette tests. Significantly increased percentages of T- and B-lymphoid cells were recorded in immunized calves.