Abstract: The invention provides transgenic nonhuman mammals capable secreting exogenous procollagen or collagen into their milk. The mammals are healthy and capable of producing procollagen or collagen at high levels, usually in trimeric form. Suitable transgenes for incorporation into the mammals are also provided.

Abstract: This invention relates to the production of recombinant proteins, such as coagulation factors VIII and IX, tissue plasminogen activator (TPA), urokinase, growth hormone, insulin, interferons, interleukins, peptide hormones and immunoglobulins, in mammals' milk. Particularly, this invention relates to an expression system which when transgenically incorporated into a mammal permits the female species of that mammal to produce the desired recombinant protein in or along with its milk. This invention also relates to the transgenic mammal that produces the desired recombinant product in its milk.

Abstract: Transgenes for producing recombinant polypeptides transgenic bovine species. A transgene for producing recombinant polypeptides in the milk of transgenic bovine species comprises at least one expression regulation sequence, a secretory DNA sequence encoding a secretory signal sequence which is functional in mammary secretory cells of the bovine species and a recombinant DNA sequence encoding the recombinant polypeptide. Also included are methods for producing transgenic bovine species. The method includes introducing the above transgene into an embryonal target cell of a bovine species, transplanting the transgenic embryonic target cell formed thereby into a recipient bovine parent and identifying at least one female offspring which is capable of producing the recombinant polypeptide in its milk.