POSTVACCINAL IMMUNE-RESPONSE TO REGIMENS OF NEWCASTLE-DISEASE VACCINATION BY FILTER-PAPER SAMPLING TECHNIQUE

Seven hundred and ten blood samples were collected at random from comm ercial layers in Tamil Nadu on Whatman filter paper No. 1 instead of t he conventional method of serum collection. The birds were subjected t o different Newcastle disease (ND) vaccination schedules and samples w ere collected to study the vaccinal response to ND at field level. Elu ates were obtained from sample areas of filter paper using Brij-35 sol ution [detergent] and subjected to the micro haemagglutination inhibit ion (HI) test for ND antibodies. The HI titre ranged from less than 2( 4) to 2(9). The possible causes of poor immune response to ND vaccinat ions are discussed.