The story is told from the perspective of one of a handful of explorers who encountered the aliens. The explorer is sharing a terrible secret with a colleague: When the explorers encountered the aliens, the aliens politely offered to pay a small royalty fee to clone headless humans for their meat markets. The aliens had already taken DNA samples from each of the explorers and threatened to simply clone bootleg humans if the explorers did not agree to accept the offered royalty fees.
It may have been an Isaac Asimov or Ray Bradbury story, but I am not certain. Thanks!