Do you not have any local feed mills? What is the percentage of the flock raiser? I know alot of people that start their meat birds on a 20% flock raiser and keep them on that the entire time and don't have any problems. If that is all you have available then they should be fine til you can find a different feed. Sorry to say but eventually you might have to find a different brand to feed your meat birds, if they don't carry just a basic chick starter, but meat birds really do need a higher protein percentage than egg layers.. Some people on here use meal worms to up the % of protein... Hope this helps
I did a little search for you based on the location under your avatar and this is the closest feed mill i could find.. you can give them a call and see what they carry and if they don't have it, maybe they can direct you to where you need to go. I buy my feed from a local feed mill and it is the best quality feed in the area, free of hormones, antibiotics, pesticides, and ruminant meat and bone meal. Hopefully you can find a quality feed in your area.
Grasston Co-Op Feed Mill
209 Oak Street, Grasston, MN 55030
(320) 396-2497