Mosaic with a donkey nursing lion cubs

"This example of foster-mothering with different species would not have been a success; the donkey's milk would not have been rich enough for the young carnivores, who would have become progressively weaker unless some other nourishment was found for them. The experiment could have been a staged event in an arena or a wild animal farm. The sponsor of the cross-fostering probably had it depicted, and others would have wanted copies of the memorable scene." - from here..