First of all, 150 lbs of feed for 450 birds comes out to about 1/3 of a cup of feed per bird. That's not enough. Growing and developing birds need unlimited access to a feed with at least 18% protein content, all day long. Secondly, pullets that mature in the fall take longer to start laying. Thirdly, if you started them on layer feed too soon, you may have delayed the onset of lay even more.Don't know but go through bout 150lbs of feed a day. But maybe they'll start soon.