Effects of Combined Viral and Bacterial Vaccine on Production Performance in Broiler Chickens

This study formulated a novel inactivated vaccine containing Newcastle disease virus (Lasota strain), avian influenza virus (BZ strains), APG, adenovirus and ORT. The vaccine was administered to 1-day-old and 7-day-old fast-growing broiler chickens. Experimental results showed that the vaccine reduced the feed conversion ratio and induced high levels of antibodies against Newcastle disease (Lasota strain), avian influenza (BZ strains), and avian rhinotracheitis. Immunization at 1 day of age had a significant impact on the production of antibodies against adenovirus. Challenge tests indicated that the vaccine partially protected the broiler chickens against Avibacterium paragallinarum types A, B, and C in broilers. Post-mortem examination of the injection sites showed good absorption with no significant unabsorbed oil droplets or hyperplasia in both 1-day-old and 7-day-old immunized chickens. This study demonstrated that combined viral and bacterial vaccine enhanced the feed conversion ratio in broiler chickens.