Fig. 2

Antibody titre of the control and challenged hens on days 9–10 post-infection. The antibody titre was calculated as per the protocol of the Infectious Bronchitis Virus Antibody Test Kit (IDEXX Laboratories). According to the kit protocol, Sample/Positive (S/P) ratio > 0.20 shows antibody level positive for IBV. Bars represent standard deviation. Superscripts (a,b) show significant differences