Transgenic animals are basically the animals who have had their DNA manipulated by addition of foreign gene through vectors.

This is mostly for the following purposes:

1. Study of disease: Diseases such as Cancer, cystic fibrosis, Rheumatoid arthritis and Alzheimer’s can be studied through them
2. Vaccine study: testing of vaccines could be done by injecting into transgenic animals.
3. Physiological activities: study of genes and how they affect body functions could be done by introduction of genes that alter formation of some factors.
4. Biological products: Such as alpha-1-antitrypsin and alpha-lactalbumin can be obtained.

95% of the transgenic animals are MICE. Others include pigs, rabbits, sheep, cow, rats fish etc.