No it didn't. There is a lightning rifle and a sniper rifle. The sniple rifle still fires invisible slugs that pop people's heads. I don't even think it streaks.
As for the warcow, i'm sure you can find the skin somewhere for 2k4. UT3 also allows custom models, so once again I'm sure you could find a warcow skin for UT3 if anyone has made one yet. I heard a rumor awhile back that the war cow was unlockable in the special edition of UT3 but i think it was a joke.