If you aren't expecting it and you're just out hiking, I could understand being freaked out until you're out of the situation. Cows are generally friendly as hell and I really can't imagine them doing any harm, but if I saw that kinda crowd I would think to myself "this is too many cows for me to comfortable with alone in the woods". I would probably also back away and keep a tree between myself and the crowd, I'd probably have a way funnier one way conversation with the cows where I loudly explain they're probably super cool but they're really big and there's a lot of em at once and it's making me nervous and probably several apologies. A few less cows and I'd be trying to make friends tho, cows are cute as hell, had one lay down next to me and sleep with her head on my lap once.