The statement "recommended for songbirds" has nothing to do with the eventual human consumption of the seed-eaters. BOSS - in the "songbird" bags - is perfectly fine for chickens.
I used to buy a 7 lb bag at Lowe's in the garden department, but then discovered my favorite feed store carries...
I give my flock BOSS daily. I toss a couple handfuls of it over the fence into the run just before I open the gate to go start the morning chores; this helps keep them from crowding me at the gate.
I also toss them some in the evening when I get home from work, for the same reason. If...