SEROLOGICAL SCREENING FOR INFECTOUS CATTLE DISEASES: III. CHOICE OF SENTINEL ANIMALS

Ciência Rural

Rojas, José Alfonso Barajas-²  Franti, Charles¹  Riemann, Hans¹ 

[1] University of California, USA;University of México, México City, México

关键词: ELISA;    seroconversion;    young;    sentinels;    infectious diseases;   

DOI  :  10.1590/S0103-84781993000200015

学科分类：农业科学（综合）

来源: Universidade Federal de Santa Maria * Centro de Ciencias Rurais

【 摘 要 】

A herd of Cattle (Holstein-Zebu crosses) was screened bimonthly for two years by ELISA for IgG antibodies to infectious disease agents. The herd was composed of 3 age groups: Young animals ( < 4 months of age), developing animals (4-36 months of age) and producing animals ( > 36 months of age). Ali young animals received colostrum within two hours after birth. The overall consistency of ELISA results, i. e agreement between two consecutive tests was about the same for the three age groups and was lowest for infections of intermediate prevalence (40-50%). The interpretation of changes in seroprevalence is most straight forward for young animals. Young animals positive at their first test reflect the immune status of their mothers while young animals born seronegative but seroconverting reflect the incidence rate. It is concluded that young animals when tested repeatedly are the best sentinel animals.

【 授权许可】

CC BY-NC