Medication purposes
One way transgenic animals can be useful is in medical applications especially xenotransplation
Nutritional supplements
Products such as insulin, growth hormone, and blood anti-clotting factors are produced by certain genes. These may be ingected to certain cows. That way these products can be produced in the cow's milk and be comsume by humans who lack these(Margawati,2003).
Xenotransplation
Patients die every year for lack of a replacement heart, liver, or kidney. For example, about 5,000 organs are needed each year in the United Kingdom alone.However organs of normal pigs has a pig protein which clashes with the human immune system and can cause donor rejection. This is where transgenic pigs come in handy. Transgenic pigs are transgenic as scientist inserted a new gene into the pig cells which can protect them from the humman immunse system response(Medical News Today,2011). Transgenic pigs may provide the transplant organs needed to alleviate the shortfall.