In this subchapter:

(1) Dairy products

The term “dairy products” means—

(A) manufactured dairy products that are used by the Secretary to establish minimum prices for Class III and Class IV milk under a Federal milk marketing order issued under section 608c of this title; and

(B) substantially identical products designated by the Secretary.

(2) Manufacturer

The term “manufacturer” means any person engaged in the business of buying milk in commerce for the purpose of manufacturing dairy products.

(3) Secretary

The term “Secretary” means the Secretary of Agriculture.