Wavefront obj format support lines too and not only faces. Poser inclusive Poser4 use lines for dynamic hair. Poser4 is unable to render lines, but Poser5 and above yes it does.
Posers create dynamic hair as lines and it are saved in obj, pp2 or hr2 files, but if you have no application that is able to render lines these files are useless. I suppose that Lightwave or Maya can do it, but I don't know if they have full support  of the obj format.
My PropViwer 2 now can do it too.
To turn dynamic hair something more useful and compatible with normal 3d applications includind Bryce or DazStudio or Poser4 the solution is convert lines into polygons, in other words turn a line into a thin tube, of course this will increase the number of vertices and faces compared to the original.
I don't know how many faces will need to have the tube, 2, 3,4??? I think that two will not be good and more than 4 a waste of polygons. Within some days I shall know it.

Stupidity also evolves!