Anti-AFB1 Ab titers in vaccinated heifers.

Heifers of different groups were immunized according to the schedule reported in Table 1. For all the groups, booster injections were performed at week 3, 6, and 9. Ab titers were determined by the method described in the text. The titer of each immune serum was defined as the inverse of the highest dilution that gave 0.1 OD above the pre-immune serum at the same dilution and presented in table on a logarithmic scale for comparative purposes (undetectable anti-AFB1 Abs were assigned a value of 0). The fixed effects of ANOVA (i.e., week, group and their first order interaction) were significant at P