| dc.description.abstract | The objectives of this study were to determine the immune response of vaccinated layer with Newcastle Disease strain Lasota active vaccine against challenged by Newcastle Disease Gen VII and to observe clinical signs and pathology anatomy lesions of challenged chickens. Fourty commercial layer were used in this study and divided into four groups K1, K2, K3, K4 each group consisted of 10 chickens. Group K1 and K2 were unvaccinated and group K3 and K4 were vaccinated. Group K2 and K4 were challenged using Newcastle Disease Gen VII. Chickens were vaccinated at 3 rd weeks and challenge at 5th weeks (2 weeks post vaccination), with dose 104 CLD50/chicken, through oral. ND antibody titer were determined by Hemagglutination Inhibition (HI) test. The result showed that groups K1 and K2 have low level antibody compared to groups K3 and K4. Group K2 shows diarrhea clinical sign that causes death to all the chickens. Group K4 has antibody 22.5. Our result showed that ND LaSota could induce immune response against challenge by ND gen VII also reduced mortality and clinical sign. | en |
