FAQ: "Are there hormones in my milk?"


I am using my blog to answer three frequently asked questions in advance of this weekend’s FoodBlogSouth Conference in Birmingham. Yesterday I explained where people could buy our farm’s milk, and tomorrow I’ll touch on the differences between “conventional” and “organic” milk. As for today, I hope I can provide a good answer for all of you that have ever asked or wondered, “Are there hormones in my milk?”

Cows, like all living creatures that I’m aware of, naturally produce hormones in their bodies. Some of these hormones are found at very low (and very safe) levels in cows’ milk. Therefore, any dairy product you buy… whole milk, skim milk, “organic” milk, cheese, yogurt, etc…will contain traces of these naturally-occurring hormones. Perhaps where the issue has gotten confusing is in the use of supplemental rBST and the labeling of rBST-free milk.

Bovine Somatotropin is a protein hormone naturally produced in the pituitary gland of all dairy cattle. Supplemental levels of the hormone’s recombinant form (rBST) can be given to cows during certain times of their lactation to increase milk production. Essentially, the supplement helps a cow convert feed into milk more efficiently. The advantage to using rBST is that it can help a dairy produce more milk without adding more cows to the herd or growing/buying additional feed. The level of success of the supplement often depends on other factors such as feed quality and environment. We used rBST for a short time in our milking herd but did not see enough of a milk increase to warrant its continued use.  Due to that economic decision, our herd has been “rBST-free” now for well over 10 years.

example of rBST-free labeling
Numerous scientific studies have concluded that there is no difference in safety or nutrition between the milk and meat from cows that receive supplemental rBST and those that don’t. Despite this fact, many consumers have voiced their preference for milk from cows that have not received rBST supplements. As a result, several dairy processing companies have worked with cooperatives and individual dairies to secure an “rBST-free” milk supply. Many of these companies then include information on their milk jug labels or dairy food packaging identifying the product as rBST-free or containing "no artificial growth hormones".

The next time you’re standing at the dairy case in your local grocery store, please remember that ALL the milk you see before you is safe and nutritious.  Ultimately, the best dairy milk for you is whichever variety you enjoy the most, so make sure you’re including three servings of dairy products every day as part of your healthy diet!

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