In 2001, a survey to estimate the seroprevalence of paratuberculosis in dairy herds was carried out in the Veneto region (North Eastern Italy). This region has about 250,000 dairy cattle and is the 3rd milk producing area in Italy. The results of the survey showed 27% of the herds to be positive, and in those with 100 heads or more, the prevalence of infected animals reached 50%. For this reason, a three-year experimental control program for paratuberculosis focused on two issues was implemented:

1. application of biocontainment and biosecurity measures in order to prevent the introduction and spread of the disease;

2. in-farm management of the animals tested positive on the basis of a semiquantitative risk assessment taking farm productivity into account as well.

Five infected herds from 70 to 200 cows were selected on the basis of the farmers' willingness to participate. The farmers enrolled were asked to avoid introducing new animals during the study period, apply the management measures agreed, and provide program evaluation information when requested.

The management measures applied at farm level were:

· separate calving areas for positive and negative cows based on serological results at drying;

· early separation of young calves from dams at birth;

· use of colostrum from negative cows in calves born from positive dams;

· use of different grazing areas for young calves and cows.

Serological prevalence in each selected herd was evaluated by commercial ELISA at the beginning of the program. Some production phases (calving, pre-weaning calves, post-weaning calves, young heifers, pregnant heifers and lactating-dry cows) were defined and scored accordingly to the different risk of disease spreading.

The management measures were applied after testing.

All the >24 month old cows were tested serologically every six months and at drying, and whenever positive or doubtful results were observed, fecal culture and PCR were performed. Although culling of culture or PCR-positive animals was advised, the time-lag between test results and culling varied considerably both among herds and within the same herd depending on farmer attitudes and cow values.

Although not all the farmers strictly applied all the measures specified in the program, after 3 years no more clinical cases were observed and average herd seroprevalence fell from 15.0% (6.6-25.7) to 4.6% (1.0-8.9).