The best place to get bulk grain is at Mother Earth. Because it is human food grade, it's likely quite expensive...I really haven't checked prices. They get stuff in 50# sacks to put in the bulk bins. I know they will sell the bulk bags because I bought a huge bag of wheatberry from them a few years back.
We could check with someone like the feed store in Alachua that makes their own feed. I don't know if Seminole Feed makes their own anymore...they used to.
Here are a few others:
Swan's Feed Mill
8916 Fort King Rd
Zephyrhills, FL,
33541-7421
813-782-6969
Southeastern Minerals, Inc. 229-243-5202
J.B. Davis & Company 770-497-8000
Manna Pro Corporation 813-620-9007
Bernie Haskins Company 386-462-1389
Franklin Minerals 352-629-7997
Purina Mills, LLC 863-425-5544
Howland Feed Mill, Inc. 386-364-1370
Elanco Animal Health 229-241-7522
Columbia Grain 386-755-7700
Southeast Milk, Inc. 800-989-4717
Ocala Breeders Feed & Supply 352-629-8686
Cargill Nutrena Feed Division 407-846-4169
Walpole, Inc. 863-763-5593
Westway Feed Products 800-940-7253
Seminole Feed 352-629-2150
Tropicana Products, Inc. 941-742-2531
Gator Feed 863-763-3337
Dixie Feed Mill
1280 Highway 97
Molino, FL 32577
850-587-3179
Name: Howland Feed Mill
Street: 9743 US Highway 90
Live Oak, fl 32060-
Phone: (386) 364-1370
Don't know if any of these places sells bulk grain...but it's a starting place. Please post whatever you find out!!