You could call your state poultry expert; here in Michigan I'd call either the poultry science department at Michigan state U., or Dr. Fulton at the MSU Vet. path lab.
Mary
It's also about the vitamin/ mineral mix, and the balance of ingredients, and freshness. You would be better off moving it on instead. Ouch! 400 pounds! Someone may be happy to pick it up, rather than you having to deliver it. I hope it's still in the feed bags?
Mary