Is '"what kills what" to mature a subject for a 5 year old?

My daughter the other day (she is 5) was watching a nature documentary and it showed a lion killing a zebra, she is very inquisitive by nature and after the documentary she started asking me what can kill what? i.e. Can a tiger kill a lion, can a lion kill a hippo, and it went on and on she even asked if an ostrich can kill hyena. I was answer them but then it started to seem a bit too morbid of a conversation to have with a 5 year old, so I managed to steer the conversation to some other topic. Do you think it’s ok to talk about the topic of death and killing with a 5 year old or is that too harsh a subject at such a young age?