rBST/rBGH – The skinny on bovine hormones.


Recumbinent Bovine somatotropin (rbST) is an animal drug approved by the FDA, to increase milk production in dairy cows. This drug is based on the growth hormone bovine somatotropin or bovine growth hormone (bst or bgh), that is naturally produced in cattle. Growth hormone is a protein hormone produced in the pituitary gland of animals, including humans, and is essential for normal growth, development, and health maintenance.Early research in the 1930s and 1940s in Russia and England found that milk production in cows could be increased by injecting cattle pituitary extracts, specifically bST. English scientists attempted to increase milk production in cows during World War II with pituitary-derived bST to alleviate food shortages. However, it wasn’t until the 1980s that it became technically possible and economically feasible to produce large commercial quantities of bST by a process using biotechnology. The bST derived by this process is typically called “recombinant” bST or “rbST”. This process is also advantageous for producing a more consistent and purified source of bST.

The FDA approves an animal drug only after information and/or studies have shown that the food (in this case, milk and meat) from the treated animals is safe for people to eat, and that the drug does not harm treated animals, or the environment. The drug also must be effective, meaning that it works as intended. The labeling for animal drug products provides all instructions for safe and effective use and is approved by FDA. The FDA publishes public documents (Freedom of Information Summaries) on its website that summarize the information that the FDA used to determine that the drug is safe for the treated animals, the animal products (edible tissues such as meat and milk) are safe for humans to eat, and that the product is effective.
FDA approved a bST product in 1993 with the brand name “Posilac®” after determining that its use would be safe and effective. Posilac® is approved for over-the-counter use in dairy cows starting at around 2 months after the cow has a calf until the end of the lactation period. During this time, cows are injected with Posilac® subcutaneously (under the skin) every 14 days. A cow’s typical lactation period is approximately 10 months long, starting right after she has a calf. Thus, treated dairy cows are typically given Posilac® for about 8 months of the year. After the 10 month lactation period, the producer stops milking the cow to allow a 2-4 month period for her mammary gland to rest and regenerate before she has a calf and starts the next lactation period. As these are guidelines, some dairy farmers choose to use rbst for different time frames. Regardless, dairy cattle are not injected every day, or in quantities that would make them ill, or be traceable in human consumption.
A key factor in FDA’s determination that milk and meat from cows treated with Posilac® is safe for humans to eat is that bST is a large protein. When they are eaten, proteins are broken down by digestive enzymes in the human gastrointestinal tract. Furthermore, even if it was injected, the human body doesn’t recognize bST because its structure is significantly different from the somatotropin produced in the human pituitary gland. Posilac® has a zero day withdrawal. This means that the milk and meat from cows is safe for humans to eat at any time after the animal is treated with Posilac®. Numerous international health and food safety organizations and many national regulatory agencies have confirmed the safety of milk and meat from bST-treated cows for human consumption.
FDA evaluated the results of numerous studies before approval, to determine if Posilac® was safe for treated dairy cows. Many of the studies were conducted under typical farm conditions in multiple regions of the U.S. The effects of treatment were evaluated on all aspects of cows’ health, feed intake, ability to have a calf, and the health of their offspring. FDA concluded that Posilac® was safe to use in healthy dairy cows. Some increased side effects were observed in Posilac®-treated cows, but FDA determined that these effects were manageable under normal U.S. farming conditions. The labeling for the product identifies the potential side effects to treated cows so that dairy farmers can make an informed decision on whether to use Posilac® in their herd. A post-approval monitoring study in 28 herds around the U.S. and including more than 1000 dairy cows confirmed the safety of the product to treated dairy cows. 

Another important thing to remember, is that when a dairy cow is given rbst in order to produce more milk, they also have a greater intake of feed, grass, water, and needed rest. It does not mean that the dairy cow will produce more milk on the same amount of nutritional intake. That would not be healthy for the dairy cattle at all, which would cause more health issues for the herd, and in turn cause a financial hardship for the producer. There are plenty of dairy farmers who have decided to stop using rbst strictly for the increased feed intake from the herd, which costs more. The other big factor would be the extremely low milk prices that are putting more dairy farmers out of business. There is no need to produce more milk. With the consumers of the world scared of what could or could not be in their food, that leaves a lot of conspiracy theorists the ability to use inaccurate information and mythical exaggerations as to what rbst or rbgh is or is not. In fact, of all the sites I have been poking through, the funniest one I found was the blog of Mr. John Robbins, who seems to be just the epitome of the  “corporations of any kind are evil and everyone is against us” way of thinking. I laugh when I hear this kind of stuff, not because I want to offend anyone, but because I truely believe in what I do, and in science as a whole. However, if you do want to check out his blog, I’ll put the link below. He brings up a lot of consumer concerns about the whole cancer links to rbst/rbgh. I will also link the information put forth by the American Cancer Society that shows that there are no founded studies to say there is, so chew on that for a moment please. 

Lastly, I will add in, that in no way do I promote Monsanto, but I also don’t feel as though I need to portray them in a negative light. I’ll have another post about them later, but in all honesty I have better things to do with my time and this blog, than to harp on a businesses mistakes and pick apart every little thing they have ever done or said. I leave that for others who have nothing better to do. I have food to grow and cattle to raise. 

Sites/reports to check out for more Info:

2013 FDA Affirmation: http://apps.who.int/iris/bitstream/10665/127845/1/9789241209885_eng.pdf?ua=1

2016 Response to Citizen Petition with Reasons: https://www.regulations.gov/document?D=FDA-2007-P-0119-0007

This guy: http://johnrobbins.info/blog/is-rbst-the-same-as-rbgh/

The American Cancer Society: https://www.cancer.org/cancer/cancer-causes/recombinant-bovine-growth-hormone.html