Minimum and maximum amount of beefalo spawned in a world?

[Sir Noel]

I started up a world and there was a pretty big savannah, so I checked around and saw a lone beefalo, so I killed it (assuming there were more). I saw another lone beefalo and thought it was a bit weird there was another by itself, but I figured there would be another and killed that one too. No other beefalo in the entire world, even in the other savannah. I didn't even know this was a thing...