Figure 3.

Growth rates (A, B) and time course of rectal body temperature (C) and clinical signs (D) during infection. “Vaccinated” — vaccinated but not challenged. “Challenged” — not vaccinated but challenged. Average daily weight gain was calculated for each group by dividing the total weight gain in a period of time by the number of days in the period: i) from vaccination (or control inoculation) to challenge; ii) during the first 13 d after challenge (day 0 to day 13); iii) during the first 27 d after challenge; and iv) during the entire period of the experiment. Growth rate was obtained by dividing the weight gain by the initial weight before challenge for each day after challenge. Clinical signs were scored daily according to the system presented in Table I. Different superscripts indicate a significant difference (P < 0.05) between the groups, and an asterisk indicates a significant difference (P < 0.05) between the vaccinated-challenged and the nonvaccinated-challenged groups.