30 hens? no way. The reason I said that is not ecause of fertilisation but 1 rooster can only protect and feed that many usually. Smaller chucks are more active and so can watch over more hens. 1 of my roos fertilises about 22 hens but 30 is crazy.
Well I have the proof sitting in the coop.
Many people have large flocks of hens with no rooster, hens can think for themselves and don't need a rooster to feed them or watch the sky for them. A rooster is not a requirement but an extra set of eyes on the sky is nice.