Fig 1.

Standard tube agglutination responses of bison after experimental intraconjunctival challenge with 10⁷ CFU of B. abortus strain 2308 in midgestation. Bison were vaccinated i.m. as calves with 1.1 × 10¹⁰ CFU (hand RB51) or 2.2 × 10¹⁰ CFU (dart RB51) RB51 or as calves and yearlings with 1.1 × 10¹⁰ and 2.2 × 10¹⁰ CFU (booster RB51). Data are reported as mean titer ± standard error of the mean (SEM). All bison in the control treatment aborted or had live calves prior to the 8-week postchallenge (PC) sampling.