Just outside New Vegas, the brahmin have been hostile towards us. Boone has been shooting them down, but they've definitely been charging. Is he aggroing them or are they just nutty?

I wonder if it is some town quest that got triggered without the Journal update telling you what is going on. There was mention in the area around Vegas about some trouble with the Brahmin but I did not pay attention at the time.

I have run into some hostile Brahman also so can confirm this, later I ran into docile ones. Perhaps they were just wild? As they go down in about two shots it's not to big of a deal. The one's that attacked me were North of Vegas on that strip off .... don't remember what it's called in-game but in real life it's the beltway between 93 and 95. Some old abandoned ranch's it looked like.

Perhaps there is a Brahman faction? :rolleyes:

I haven't ran into any hostile brahmin yet. What was the location called?

They must be the Battle Cattle the radio mentions!

I get them too. They are marked as hostile, but they don't attack. If you're alone, you can simply ignore them. Otherwise, your companions will go ballistic on them.