Several chains I have bought from have their own dairies:
Publix has three Dairy Processing facilities within Publix
Manufacturing: Lakeland, FL, operating since 1980; Deerfield Beach,
FL, since 1988; and Dacula, GA, since 1995.
The facilities employ approximately 575 associates and are certified
Kosher by the Orthodox Union (OU). Combined, the facilities process
and manufacture milk, flavored milk, eggnog, orange juice, grapefruit
juice, fruit drinks, lemonade, packaged ice, drinking and spring
water, carbonated beverages, ice cream, and cultured products such as
yogurt, sour cream, and cottage cheese. Each facility also blow molds
½ gallon and gallon HDPE bottles.
The Publix Dairies produce approximately 1.7 billion pounds of product
annually for sale in our retail stores as well as to external
customers.