Is that an actual fact or just an educated opinion? Is 'developing" antibodies the only way to have them in your blood? Asking both questions because I don't know. Eating other proteins from animals are easily absorbed and bioavailable. Wonder why not an antibody protein?
First off our anatomy would have to be close enough for a deer antibody to work in the human immune system.. it is not. If it was there would be tons of research being done on deer in order to cure human illnesses. Can you lead to any at all?
Second, you would have to assume the antibody would be able to survive the gastric system and to be absorbed through the intestinal membrane and make it in the blood system.
Third, antibodies are destroyed at temps over 150 degrees farenheit.