To build on what mentsch1 has written:
The only possible Isur I can imagine to purchase eggs from a farm that is Over on Tza’ar Ba’alei Chayim (again, this has absolutely nothing to do with condoning such practices) would be either Lifnei Iver or Mesayei’a li’Dvar Aveirah. Since, however, they are carrying out their practices of their own volition, and could do so whether or not we buy the eggs (nobody is demanding eggs at a certain price or frequency, and it is definitely not Trei Ibra d’Nahara), these would not seem to apply in such a case.
In the Mishnayos in Shabbos it is clear that animals were force-fed in order to be fattened for slaughter (the only Shaila being if such is Mutar on Shabbos). In the famous story involving Rebbi, a frightened calf being led to the slaughter hid its face in Rebbi’s garment, and he sent it off with a “Go – for this you have been created”. He was punished according to his Darga for being insensitive to the calf’s “feelings” – not because his message was incorrect.
Obviously we have Chiyuvim. The first stage, for those in the position to do something about it, is to clarify what those Chiyuvim are with a competent Halachic authority (which I am not).