rBGH and the (mis)Use of Science
What is rBGH/rBST/POSILAC?
the center of this controversy is POSILAC, Monsanto’s rBST product. The
terms bGH (bovine growth hormone), bST (bovine somatotropine) are often
used interchangeably. bST is a protein hormone that is produced
naturally in the pituitary gland of a dairy cow. It is one of several
hormones that helps to regulate milk production. The term rBST or rBGH
(the ‘r’ standing for recombinant) is used to refer to the synthetic
bST that is injected into dairy milk cows. This synthetic hormone is
created through the use of fermentation technology, as shown in Figure
3 to the left. These synthetic injections, or supplements as
Monsanto prefers to call them, can increase milk production by 10-20%
in a dairy cow.
Figure 3: Monsanto's rBST Product
POSILAC is the rBST product marketed by Monsanto, the only rBST product
available. After injection, POSILAC flows to the liver through the
blood stream and stimulates the production of an insulin-like growth
factor (IGF-1). IGF-1 is also a protein hormone that helps to convert a
cow’s feed into milk. In essence, POSILAC increases the efficiency of a
cow’s conversion of feed to milk production.
Figure 4: How to Handle POSILAC
How Posilac Is Made
Figure 5: How POSILAC is Made
Figure 6: An illustration of Posilac Injection Sites