Do cows not have animation data for attakc or defence?

Yes they have.
Just for fun I made a very aggressive and foolhardy cow, attacked it and lost my life to the horns. LOL

I kept puching a cow and it stood there waiting to die ....... thats stange how I can do to make a cow get angry?

Just like you would do for any other actor: Go to the AI Data tab and change "Aggression" and "Confidence".