Blood Drinking Vampire Bats

Vampire bats typically feed on fresh cow blood and only rarely bite humans. In zoo conditions, especially, an anti coagulant is added to the blood to keep it fresh enough for feeding via little peatre dishes that are placed out in the enclosure. So this is a product that is derived from the hemoglobin, the oxygen carrying protein that would be found in the red blood cells of cows or some other bovine. And i think this is in line with a lot of the stuff i was seeing about jehovah's witnesss beliefs that often that they will receive certain types of blood poducts but the objection more often is to whole blood.