The commercial dairy herd is located in Galicia (North West of Spain), a densely populated region with farms that average a capacity of 40 cows. This is a large herd with 400 Holstein dairy cows (250 milking) and it is engaged in a voluntary regional health program for the control and eradication of IBR, BVD, Neospora and Johne’s disease since 2005. This farm has regularly vaccinated for BVD, following an every 6 months booster dose protocol, and it was considered to be free of IBR according to yearly serology control for IBR and bulk tank milk analysis followed in the region.