Fig. 2From: Field application of an indirect gE ELISA on pooled milk samples for the control of IBR in free and marker vaccinated dairy herdsDistribution of IgG enriched fractions ELISA optical density (%OD) related to two/three sampling in the four farms (a, b, c, d) with new BoHV1(Bovine Herpesvirus 1) outbreaks detected across the 18 months of the present study. The dotted lines indicate the threshold values of the gE (glycoprotein E) indirect ELISABack to article page