<;P>;PROBLEM TO BE SOLVED: To provide a transgenic avian which has a foreign gene containing sequence encoding feline-derived protein and method for production thereof. <;P>;SOLUTION: The invention relates to the transgenic avian produced by infecting the heart or a blood vessel formed in the initial stage of development of the embryo of an avian with a replication-deficient retrovirus having the foreign gene therein by means of microinjection and incubating the embryo. The feline-derived protein can be produced by using the transgenic avian. <;P>;COPYRIGHT: (C)2007,JPO&INPIT