Field study on immune response and performance of maternally immune commercial broiler chickens to live intermediate infectious bursal disease vaccine

ABSTRACT

In this study, 8000 Hubbared 1-day old broiler chicks having maternal antibodies to infectious bursal disease [IBD] were reared on deep litter in a poultry farm. The chicks were received IBD [Bursine-2] intermediate vaccine at the 12[th] day of life via drinking water to investigate its immunogenicity and its effect on broiler performance. No IBD related clinical signs or mortalities or lesions were observed after vaccination till the end of the breeding period [7 weeks]. The result of serological response to IBDV vaccines using ELISA test showed that the maternal antibody titer to IBD antigen in 1 day old chicks was 5571.1 +/- 1761.8 and waned to1237.7 +/- 915.8 at 2 weeks [2 days after vaccination. At the 3[rd] and 4[th] weeks after vaccination IBD ELISA titres were increased to 2662.1 +/- 186.3 and 3394.1 +/- 768.8; respectively. This result revealed that the used live IBD vaccine was able to induce antibody levels in chickens with maternal IBD antibodies. The best weekly feed conversion rate [FCR] was recorded at the 4[th] week [1.31] and the 6[th] week [1.71] with total FCR of 1.89. Mortality rate in the susceptible age [2-6 week] was the lowest [0.4-.73%] with total mortality of 3.27 at the end of the 7[th]. These fining pointed out that live IBD intermediate Burcin-2 vaccine was save, immunogenic to maternally immune chicks and has no adverse effect on performance of vaccinate chickens