Analysis of titer difference of Newcastle disease antibody in different samples of Beijing-You chicken

Yan Zhixun; Zeng Lingchao; Chu Qin; Geng Ailian; Zhang Jian; Zhang Yao; Chen Xia; Liu Huagui

doi:10.20154/j.cnki.issn1672-9692.2024.12.006

Abstract：The aim of this experiment was to study the effect of different samples of Beijing-You chicken on the detection result of Newcastle disease(ND)antibody,and to explore the best treatment method for yolk samples.A total of 40 healthy Beijing-You chickens were selected 100 days after immunization with ND vaccine(La Sota strain),40 males and 30 females,and 30 non-immunized chickens were collected to separate serum and plasma samples,and one breeding egg was collected from each hen to separate yolk and albumen.In the immune group,yolk and albumen were diluted at the ratio of sample:normal saline=1∶1,1∶2,1∶3,respectively.In the non-immune group,yolk and albumen were diluted at the ratio of sample:normal saline=1∶1,and the titer of ND antibody in different samples was detected by hemagglutination inhibition test.The results showed that the antibody titers of ND serum and plasma were 7.20 and 6.95 log2 in hens and 7.85 and 7.58 log2 in cocks,respectively.Among different samples,the titer of ND antibody in serum was the highest(7.20 log2),and there was no significant difference in titer of ND antibody in plasma,albumen 1:1 and egg yolk 1:1 compared with the serum detection results(P>0.05),but there was false positive phenomenon in the direct detection of ND antibody in albumen samples.The results showed that there was no significant difference between the titers of ND antibody measured by plasma and yolk diluted with normal saline at 1:1 ratio,and they could be substituted for each other for ND antibody detection.There were false positive results in the detection of ND antibody when the albumen samples were diluted by 1∶1 proportion of normal saline.