Figure 6.

Antibody response of chickens after immunization with CK/CH/JS/TAHY oil-emulsion vaccine. The primary immunization was carried out at 7 D of age (0 D post-primary immunization). The second immunization was carried out at 14 D post-primary immunization. The third immunization was carried out 3 wk after the second immunization challenge (35 D post-primary immunization). The error bars indicate means ± standard error of mean. Asterisks (*) mark the days in which the antibody titers were significantly different between inoculated with CK/CH/JS/TAHY inactivated vaccine and infection control groups (P < 0.05).