The Effect of Antibiofin® on the Immune Response Against Avian Influenza Subtype H9N2 Vaccine in Broiler Chickens

Abstract Background: Some herbs such as thyme (Thymus vulgaris) are rich in flavonoids, act as antioxidants, and may improve the immune function. Objectives: This study was performed to investigate the effects of Antibiofin® (mostly including Thymus vulgaris) in drinking water on immune response against avian influenza (AI) subtype H9N2 vaccine of broiler chickens. Materials and Methods: One hundred eighty one-day-old broiler chickens were purchased and divided into 4 equal groups. Chickens of groups A and B received 0.1% and 0.2% Antibiofin® respectively in their drinking water. Chickens of group C did not receive Antibiofin® but were vaccinated against AI. Chickens of group D were not vaccinated against influenza disease and did not receive Antibiofin®. All groups except group D were vaccinated with AI-ND killed. Blood samples were collected before vaccination as well as after vaccination on days 14, 21 and 28, and antibody titer against influenza disease vaccine was determined by hemagglutination inhibition (HI) test. Results: The results of this study showed that receiving Antibiofin® at 0.1% and 0.2% concentrations, 14 and 28 days after vaccination, could increase the specific antibody titer against avian influenza subtype H9N2 vaccine compared to the control group. Conclusions: Antibiofin® enhanced the systemic antibody response against avian influenza subtype H9N2 vaccine in broiler chickens.