查看文章

Study design

A follow-up study was performed on 20 animals (ten positives and ten negatives), selected on the basis of the results of the previous testing. Animals were considered to be ‘positive’if they gave positive results with at least at two tests, and ‘negative’if they gave negative results with all the tests performed. Samples of milk, faeces and vaginal swabs from the 20 selected animals were collected every 3 months and tested by real-time PCR. The serological investigation was performed on all the milking cows. With the aim of monitoring the natural outbreak extinction, none of the cows were treated during the study period.