Study on the effect of green tea powder on the immune response against newcastle disease in Kien chickens
This study aimed to determine the effect of adding green tea powder to the diet on the immune response against Newcastle disease in Kien chickens aged 1 to 56 days. A total of 90 chickens were randomized to a completely randomized design with 3 treatments and 3 replications. Treatment 1 (control) included Newcastle disease vaccine and no green tea powder in the diet; Treatment 2 included Newcastle disease vaccine and 1% green tea powder; and Treatment 3 included Newcastle disease vaccine and 2% green tea powder. Antibodies against Newcastle disease in chickens were tested using the Haemagglutination Inhibition (HI) reaction to determine antibody titers and the protective efficacy of the treatments. The results obtained are as follows: After the first vaccination (19-day-old chickens), the protection rates in treatments 1, 2, and 3 were 30.00%, 46.67%, and 33.33%, respectively, with antibody titers of 1.30 log2; 1.86 log2 and 1.67 log2. After the second vaccination (33-day-old chickens), the protection rates in treatments 1, 2, and 3 were 43.33%; 80.00% and 56.67%, respectively, with antibody titers of 2.00 log2; 3.37 log2 and 2.7 log2. After the third vaccination (56-day-old chickens), the protection rates in treatments 1, 2, and 3 were 80%; 100% and 100%, respectively, with antibody titers of 3.7 log2; 4.97 log2 and 4.4 log2. Thus, the study results show that adding green tea powder to the diet at a dose of 1% increased the immune response of chickens against Newcastle disease compared to adding 2% green tea powder to the diet.
