The Food and Drug Administration recently approved the first drug to be biologically produced from genetically modified livestock. The drug antithrombin, a protein which helps prevent blood clotting, will be produced by goats that have been genetically modified with the human version of the gene.
Cleverly, researchers spliced the gene in a specific part of the goat genome so that the goats would only produce the protein in their milk. It's relatively straightforward to isolate the protein drug from other milk proteins and package it for market.
Given that the "bio-pharming" approach has been discussed for decades, it will be interesting to see if the promises of cheaper and higher quality drugs come true.
However, some animal rights groups have expressed concern about the use of animals for drug production. Other groups are concerned about monitoring these transgenic animals, so that they do not enter the food supply.