Fig. 1

Kaplan Meyer graph representing the percentage of cattle within group 1–3, versus the duration of the period between second vaccination and estrus. The median times are 113, 191 and 229 days in the three groups. Group 1 (blue) = < 28 days, group 2 (brown) = 28–35 days, and group 3 (green) = > 35 days between the vaccinations. † mean censored data