At first it really bugged me for some reason. I spent hours with the scythe cutting it down in great swathes. Over time it has slowly disappeared from the fields as the soil condition improved. Blue top and bracken are both good indicators of problem soil. The main solution was to ensure the soils were grazed properly, meaning get rid of the bloody horses. I now take care to spell the fields between grazing every few months and to allow time for the pasture to go to seed at least once every two years.
The blue top does not worry me any more as I have come to realize it has its place even though it is a feral weed. It even has its uses, the cattle appear to use it as an occasional medicinal herb and the early settlers to this area also apparently used it as a poultice on wounds for its mild antiseptic qualities.