No person shall distribute commercial feed in the commonwealth unless the feed is registered with the Department, except that the following feeds are exempt from this requirement:

1. (1) customer formula feeds, raw meat, hay, straw, stover, silages, cobs, husk, hulls when underground and not intermixed with other materials and not adulterated;

2. (2) individual chemical compounds which meet all of the following criteria:

   1. (a) The Association of American Feed Control Officials has adopted a definition of the product;
   2. (b) The product is either GRAS or is not covered by a specific Food and Drug Administration regulation;
   3. (c) The product is either a natural occurring product of relatively uniform chemical composition or is manufactured to meet the AAFCO definition of the product;
   4. (d) The use of the product in the feed industry constitutes a minor portion of its total industrial use; and
3. (3) Small quantities of additives, which are intended to impart special desirable characteristics shall be permitted.