How does bST work?
The pituitary gland of the dairy cow normally produces bST. bST is one of a group of hormones produced naturally in the cow that controls milk production. Supplemental rbST can be injected into a dairy cow. Both sources of bST (that produced by the cow herself and supplemental) are carried to the liver of the cow via the blood stream. bST in the liver stimulates this organ to produce insulin-like growth factor (IGF-1), another protein hormone that plays an important role in helping regulate the conversion of dietary nutrients into milk. Supplemental bST helps increase the efficiency of conversion of feed to milk in the cow’s body. It has been shown that to support increased milk production, a cow supplemented with rbST automatically consumes more feed. The amount of nutrients required for the cow’s body maintenance remain unchanged, therefore, the cow’s increased nutrient intake is used primarily for milk production. bST is found in trace amounts in milk from all cows, unsupplemented a
