Recombinant bovine somatotropin (rBST) is a synthetic version of the bovine growth hormone given to dairy cattle by injection to increase milk production. According to the FDA, no significant difference has been shown between milk derived from cows treated with artificial growth hormones and those not treated with artificial growth hormones. Here at Ruby Jewel we like to keep things clean and simple and have chosen to actively source ingredients that are as natural as possible. Which means all our dairy is rBST-Free.