Of course. Do humans not raise animals to feed from them? Such are we to them.

( Though he smiles, his tone is faintly wry. )

Still, it is a curious thing. Humans fear death, and vampires would have humans remain live to feed from - and so you come upon a strange habit wherein humans come to thank the lords who partake in them, and fear the chance that, perhaps, these lords may move onto some more pliable food source, and leave them all to die.