Mastercaster,the type of blood doesn't matter,it's the cue to track and the reason for the dog to follow "something".It also doesn't matter what animal is at the end of the track,although I personally wouldn't put a predatory animal at the end of the track if she is inexperienced.
You want to teach the dog desire and will to track and success at the end,aging of the track depends on the desire of your dog.

Rainer