I need to spray something around the bottom strand of my fence (hotwire) to kill weeds and small trees that have popped up with all the rain we've had.  Goes without saying I need it to be safe for my herd--I don't have anywhere to move them when I put it out.  Thanks y'all 

Glysophate

Tractor supply or your local feed store

There is literally nothing safer than glyphosate. 

I second this endorsement that nothing is safer than glyphosate!  

Thank y'all--and "hey there" to my AR neighbors!!