No abstract

Purpose Infectious bursal disease (IBD) is one of the most endemic diseases of commercial poultry in Ethiopia. Vaccination is used as the major means of IBD prevention and control. A study was conducted to compare the immunogenicity of two commercially available IBD vaccines in broiler chicken with maternally derived antibody (MDA). Methods A total of 270 day-one-old chicks were randomly assigned to three groups, group 1 vaccinated with product A vaccine at the age of 7 and 19 days and group 2 with product B vaccine on day 15 and 22 while group 3 were kept as control. Six chickens were also randomly selected and bled on day 1 for differential leukocyte count (DLC) and determination of MDA. Representative chickens from each group were bled at 24th and 42nd days of age for antibody titration using the indirect ELISA test. DLC scores were determined in the 1st and 24th days. Results The result revealed highly significant differences ( P = 0.001) between group 1 and group 2 in DLC at 24th days of age. Antibody titers against IBD were differed significantly ( P = 0.02) at 24th and 42nd days of age in broilers vaccinated with product A and product B vaccines. Conclusion Both vaccines have induced an adequate immunological response at the end of the experiment; however, product A has shown significantly higher antibody titers against the IBDV and DLC than product B.

Infectious bursal disease (IBD) is one of the most endemic diseases of commercial poultry in Ethiopia. Vaccination has been practiced as the major means of IBD prevention and control. A study was conducted to determine and compare the immunogenicity of two commercially available IBD vaccines in broiler chicken with maternally derived antibody (MDA). Day-old chickens of 270 were randomly assigned to three groups, group 1 vaccinated with brand 1 vaccine at 7th and 19th days and group 2 with brand 2 vaccine at 15th and 22nd days while group 3 were kept as control. Six chickens were also randomly selected and bled on day 1 for differential leukocyte count (DLC) and determination of MDA. Representative chickens from each group were bled at 24th and 42nd days of age for antibody titration using the indirect ELISA test. DLC scores were determined in the 1st and 24th days. The result revealed highly significant differences (P = 0.001) between group 1 and group 2 in DLC at 24th days of age. Antibody titers against IBD were differed significantly (P = 0.02) at 24th and 42nd days of age in broilers vaccinated with brand 1 and brand 2 vaccines. It is concluded that although both brands of vaccine induce an adequate immunological response at the end of the experiment, brand 1 vaccine has shown significantly high antibody titers against the IBDV and DLC than brand 2.

The ban on antibiotic growth promoters in livestock feeding has encouraged the utilization of phytogenic feed additives. These phytogenics recently attracted much attention and are generally recognized as residue-free ideal feed additives in animal Production. The current study was conducted to investigate the effects of the phytogenic herbs on feed intake, feed conversion ratio, and immune responses associated with the infectious bursal disease (IBD) vaccine in broiler chickens. For this study, 360 day-old broiler chicks were randomly assigned to six feeding trials, each with three replicates containing 20 chicks. The control group (T1) was only fed a basal diet alone, while the treatment groups were given the basal diet supplemented with 1% of basil (T2), lemongrass (T3), peppermint (T4), rosemary (T5), and thyme (T6) leaves powder, respectively. Body weight, feed intake, and feed conversion ratio were recorded. All chicks were vaccinated against IBD on days 7 and 19. A serology test was conducted to check the antibody titer against the IBD vaccine. The findings of this study showed that chickens in group T2 had significantly consumed more feed, followed by T1 and T6. During the overall study period, chickens in group T4 had significantly better feed conversion efficiency, followed by T3 and T6. Chickens in groups T5 and T6 showed a more pronounced antibody titer against the IBD vaccine at days 21 and 42 of the experiment. Therefore, these findings indicated that supplementation of basil leaf powder improved feed intake. Moreover, peppermint and lemongrass leaf powder improved the feed conversion ratio. In addition, supplementation of rosemary and thyme enhances the immune status of broiler chickens and could be considered a natural growth promoter feed additive. Therefore, further studies should be done to discover their beneficial effects to use as alternative feed additives in broiler chickens. Keywords: Body weight, Broiler chicken, Feed conversion, Feed intake, Immune response, Infectious bursa disease