Fig. 1.

Kinetics of the antibody response to challenge infection according to the treatment group and day of sampling. Prior to the infection all animals were serologically negative (threshold < 1:654, dashed line). Seven days after infection a mild increase in the antibody titres was detected with nearly equivalent values in both groups. The amount of anti-Salmonella antibodies further increased during the infection period and showed a further gain at 14 dpc with significant higher values in the controls (p = 0.001, asterisk).