Seriously, I don't know enough about this specific case to state an opinion, but I know this sort of thing goes on with other animals in zoos all the time.
It was possibly an educational thing when they fed the lions in front of kids? The real world right in front of their eyes, rather than the disney cotton wool cosy world that is all nice and touchy feely, but innacurate.
Rats are fed to snakes, crickets to lizards, chicken beef and lamb to big cats. It just makes people uncomfortable when it is a giraffe. If they were on the serengeti, they would see newborn giraffes struggling for all their worth to get up immediately, otherwise the creatures of the night get it.
It would have been nice to see it farmed out somewhere else in the perfect world, but what would that have entailed? A solitary existence? Below par care?
I'm a bit split on this one.