Comparative Evaluation of Infectious Bronchitis Vaccines in Broilers: Impact on Growth Performance, Mortality, and Immune Response

This study evaluated the effects of three commonly used imported infectious bronchitis (IB) vaccines on the health and production of broilers. Two hundred and forty day-old Ross-308 broiler chicks were randomly allotted to four groups (six replicates of ten birds each). The control group received no vaccine administration, while groups IB4-91, IBMa5C, and IBH-120 were vaccinated against IB vaccines on days 7 and 21. The vaccine used in Group IB4-91 was from Nobilis®, Vety-Care Pvt Ltd, in group IBMa5 from Nobilis®, and in group IBH-120 from Medivac, Hilton Pharma. Growth performance parameters (feed intake, body weight gain, feed conversion ratio) were not significantly different (p>0.05) among the groups throughout the 35-day trial. However, immune response and mortality were significantly influenced by vaccine type. Group IB4-91 showed a significantly higher antibody titer (p=0.032) and achieved 0% mortality, which was significantly lower (p=0.030) than the other groups. In contrast, control, IBMa5, and IBH-120 all displayed 3.33% mortality and exhibited mild to moderate respiratory symptoms, with post-mortem findings revealing tracheal and lung congestion. It is concluded that while the tested imported vaccines did not impact growth, the IB4-91 vaccine provided superior protection, as evidenced by the highest antibody titers and the complete absence of mortality.