One of the first reports of transgenic animals published in December, 1982 involved transfer of growth hormone (GH) gene, fused to the promoter of metallothionein (MT) 1 gene. Since then transgenic animals have been produced (using the methods described earlier) in a variety of animals including mice, rabbits, sheep, pigs, goats, cows, fish, etc. (Table 42.1). These transgenic animals will be utilized for their (i) efficiency in utilizing feed; (ii) ability to give leaner meat; (iii) ability to grow to marketable size sooner; (iv) resistance to certain diseases. They are also proposed to be used as bioreactors, so that they wil1 secrete valuable recombinant proteins and Pharmaceuticals in their milk, blood and urine, which can be used for extraction of these drugs. This is described as 'molecular farming' or 'molecular pharming'.