Passive mobs always have a low chance of respawning, but honestly, with the inclusion of breeding, there's pretty much no physical way that people won't get the animals they need.
Well, the only danger is that I kill them all before I start growing wheat. Though I threw down a farm, so, that shouldn't be an issue now. Hopefully.
What's the deal with the old map? I made a bed to set my spawn and when I lay down a second or two later I was at the spawn in the old map. Didn't know how to get back (so logged off and back on again).

Oh well, guess I can't sleep the night away on the server anymore. Which usually isn't a problem, but when I'm hiding in my cave at half a heart I usually want to wait until daytime to gather.
Are there some mods in play I should be reading up on? Runecraft?
Runecraft would be a good idea, yes.
Yeah, that looks complicated. Think I'll just ignore it for now.
Is that the only mod in use?