Biotechnology in general, and mammalian recombinant genetics in particular, assuredly will have a major impact on all aspects of animal science and commercial livestock production. A review of the basic molecular biology and technology involved in gene transfer in mammalian species is presented in the content of potential commercial application of these new procedures for enhancing productivity in livestock. Special emphasis is given to near-term possibilities for the application of mammalian recombinant genetics to animal growth and lactation. Key words: Biotechnology, gene transfer, livestock production