Abstract: To understand the immune status of the dairy cows from the large?scale dairy farms in Qingyuan city， and to timely evaluate the sera titers after immunization of type O and type A foot?and?mouth disease（FMD）bivalent inactivated vaccine，large scale blood sampling was performed. From 2020 to 2021，randomized blood sampling was performed in 7 large ?scale dairy farms within 4 counties in Qingyuan city. 30~50 cow sera were collected from each county. Liquid?phase?blocking enzyme?linked immunosorbent assay（ELISA）was used to test the antibodies against type O and type A FMD. The results showed that the protection rate for type O and type A FMD were 96.97%（320/ 330）and 98.18%（324/330），respectively. In conclusion，the overall immunization status of FMD was good in the large?scale dairy farms in Qingyuan city and the dairy cows were well protected.

Key words: Qingyuan City； Dairy cows； Foot?and?mouth disease； Antibodies

摘要： 为摸清清远市规模奶牛场口蹄疫的免疫状况，及时掌握奶牛接种口蹄疫O型、A型 二价灭活疫苗的免疫效果，为口蹄疫防控提供依据。2020—2021年间，对清远市4个县（市、 区）7家规模化奶牛场开展随机抽样，每个县（市、区）采集30—50份奶牛血清，利用液相阻断 ELISA检测方法进行口蹄疫O型、A型免疫抗体的检测。结果显示，330份奶牛血清中O型、A 型苗免疫抗体合格率分别为96.97%（320/330）和98.18%（324/330）。这表明清远市规模化奶牛 场口蹄疫总体免疫效果较好，奶牛群体能得到有效的保护。

关键词: 清远市； 奶牛； 口蹄疫； 抗体