Driftwood does not use milk from dairies that treat their cows with rBST (rBGH). rBST (Bovine Samatropin) was approved by the FDA for sale and use with dairy cattle starting February 4, 1994. There is absolutely no difference in milk from rBST supplemented herds as compared to non-rBST supplemented herds, and that there are no health risks involved. However, we have instructed our milk supplier that we require our raw milk only from herds that do not supplement with rBST. rSBT is no longer used in California.