I purchased 50 cornish X from the local college after they were through "experimenting" with them and asked the professor if corn would be a cheap way to add weight....i figure if it works for cattle, why not?
Here is his reply:
So what to feed them. Orshelns and TS sell good mixed feed, but it can be pricey. These birds, after the starter phase, should do well on grower diets with 18% protein or more. But what counts is your cost per gain, I don't care what the label is on the feed. You can figure 2.5 lbs of feed per pound of growth when the birds are about 6-7 weeks old. So if you bought a sack of 50 lbs for $10, then that's 20 cents per pound, or 50 cents to add one pound of weight to your birds (2.5 x .20). At $10/sack, that's about $400 per ton. You can very often buy feed at the coop much cheaper, so long as they don't make you buy a minimum. Some will even mix your own formula, or they will have one.
Don't worry about the label. If you can get turkey starter, or gamebird grower cheaper then that might make you the best money. Sure, the diets will be off a bit, but what matters on a small scale is how much it costs you and how big your birds grow. I have found that prices at coops and stores vary a lot, and often times a good gamebird starter is cheaper than a grower that contains fewer nutrients. Oh, and don't worry if you get starter or grower. If you feed a starter to older birds, who cares. They will get more nutrients, eat a bit more feed, or they may excrete a bit of undigested nutrients. What matters is money in your pocket.
So far, it seems to be working...i haven't weighed any of my birds, but the breasts i've cut off look like they're about twice the size of what i find in the grocery store!