Milk

Milk
Milk is the secreted fluid of the mammary glands of female mammals. It contains nearly all the nutrient necessary to sustain life.

Since the earliest times, mankind has used the milk of goats, sheep and cows as food.

Today the term “milk” is synonymous with cow’s milk. The milk of other animals is spelled out, e.g., sheep milk or goat mil, when supplied commercially.

In Germany, the yield of milk per cow in kg/year has increased steadily as a result of selective breeding and improvements in feed.

In some countries it is permitted to increase the yield of milk by injection of the growth hormone bovine somatropin (BST). The recombinant BST (rBST) used is identical in activity to natural BST.

This is done by taking, from the DNA of cows, the specific gene sequence that carries the instructions for preparing BST and inserting it into E.coli, which can then produce large amounts of rBST.

Natural BST consists of 190 or 191 amino acids. rBST may differ slightly in that a few extra amino acids may be attached at the N-terminal end of the BST molecule.

Due to differences in the molecular mass it is possible to distinguish between rBST and natural BST.
Milk