According to the descriptions by standard protocol of OIE (http://www.oie.int/eng/normes/MMANUAL/A_00024.htm), all animals were challenged by intradermal inoculation at two sites in the tongue with 10,000 bovine infectious doses (BID 50 ) of Asia I/HNK/CHA/05 at 28 dpv. The body temperature of the animals was monitored daily. The restrained animals were carefully examined in the mouth, and feet every day for the first 10 days after challenge.