We have raised pastured broilers for several years now and have experimented with commercial feed, organic feed and various recipes for feed. This year I tried a very low tech mix of corn, oats, barley, soybeans and fishmeal. I wanted to use the multigrain formula partly to see how it would work and partly to try to limit the GM ingredients. all the local corn is GM and I though maybe the oats and barley would have a better chance of being non-GM. Of course the GM is not labeled here is the land of the free so you cannot tell unless you go for the certified organic. I though the fishmeal as a non-GM would help dilute the likely GM soybeans in the protein component of the feed. Anyway it is a 20% protein recipe and cost about $15/50lb when I buy 1 ton. A couple of observation is that the birds grow a little slower than with the commercial mix. I noticed they don't always eat all the roasted soybeans. This is the protein so that would slow them down. there was a late pen of birds on pasture and i though it good to give them extra feed as it got colder. This backfired as they ate everything else and left the soybeans. That went on for almost a week before it dawned on me what was going on. I cut them back to the regular amount and they ate it all and resumed weight gain.
When they broilers- 50 of them - are in the brooder - 8x8' with thermostat controlled heat lamp- they usually spend 2 weeks and are ready to go out to pasture. If it is early in the year and bad weather I may keep them there for 3 weeks. After 2 weeks the brooder is pretty nasty and i have to throw in a inch or two of the wood chips on the floor. If they stay another week it is even nastier and it needs more wood chips before anyone wants to step in there to collect the birds. That is on the commercial feed. with this new mix I kept these 50 birds in there almost 4 weeks and the brooder was about like 1 week with the commercial feed. So I think about how bad your tummy feels when you eats some bad food and you get diarrhea. That must be how commercial food with all the chemicals affects animals.