The regulatory clearance — the first of an intentional genomic alteration in a product with both food and medical uses — means the animals could be safer sources of not just food but also treatments such as the blood-thinner heparin.

"Today's first ever approval of an animal biotechnology product for both food and as a potential source for biomedical use represents a tremendous milestone for scientific innovation," FDA Commissioner Stephen Hahn said in a statement.

There have been four previous approvals for such genetic engineering in animals, three for biomedical purposes and one for food, but none for both biomedicine and food, Steven Solomon, director of the FDA's Center for Veterinary Medicine, said in a conference call with reporters.