Determination of the best time for FMD Vaccination in north of Iran

ABESTRACT: For study of F.M.D disease antibody induced by vaccination in native cow, 50 calves in 2 group according in 6 to 9 month age selected. Group 1 – 40 calves with single vaccination Group 2 –10 calves with twice vaccination (rupple dose) with 28 days interval. The killed triple vaccine produced by Razi institute contains O, A, Asia 1 strains were used. Control group contain (10 calves) without vaccination selected for observation of foot and mouth disease appearance at 1.5 years of research. All of the calves didnʹt have titer against F.M.D in serum before vaccination. Blood samples were taken in different (15) time after vaccination with 15-30 day interval. Serum were examined by serum neutralization test that neutralizing antibodies from 1/2 to 1/64 dilution. The results showed that 66.7% first group and 71.6% second group have desire titer up to 1/4 titer level decreased at month 2, 10 after vaccination in first group and month 2, 9, 12 in second group. Peak of titer appear in month 7 after vaccination in first group and month 5 for second group. Titer1/4: relative immunity and titer1/8: enough immunity described to this study.