抄録
Survey was undertaken on 307 blood samples at Qassim region, revealed that 235 (76.5%) and 3 (0.98%) of cattle were infected with Theileria annulata and Anaplasma marginale respectively. T. annulata was the prevalent blood parasites among cattle while A. marginale was scarcely encountered. The monthly incidence of T. annulata ranged between 38.5% in March to 94.7% in October. Also the infection rate reached to the maximum (84.3%) in autumn and summer seasons, while it was drop off to minimum (59.4%) in spring season. It has been found that there was no significance difference between both infection rates of the laboratory and abattoir collected samples. However, the intensity of parasite was differ between the two groups.
