How many hens do you have? I mean is this a large percentage of them? How old are they? And, sorry.. are you sure they have gone broody? Seems odd to have so many go broody.. are they a "broody" breed? Orpingtons or Cochins, etc.?
I know that I hate to try to break my few hens that go broody.. it is emotionally wrenching for me to try to do that.. but, after about three weeks the last time.. (and I was throwing away the eggs due to worming)... my neighbor suggested I take away the "bucket" .. the nest.. I have some nests in five gallon buckets (with a hole cut in them) -- as the hens like the privacy... so.. after I took it away.. took the buckets out.. she got over her broody in a few days.
Other than giving them extra food and water on the nests.. and letting nature take its course... I don't know what else to suggest.. it's a hard thing to do. So sorry..
Good luck.
