All vaccinated cattle were challenged with 10,000 BID 50 of Asia I/HNK/CHA/05 at 28 dpv. Body temperature, mouth and feet were observed consecutively for ten days to evaluate the incidence of disease (Table 3) . Four of the five cattle were considered completely protected. Only one vaccinated cattle, No45, developed lesions. The lesions were detectable by 6 dpc and the clinical signs were less severe compared to control group. By contrast, vesicles developed in the control animals by 2 dpc at the sites of all feet and mouth. This indicated that antigen produced in silkworm could be effectively protective.