my goats browse part of the yr but always with lots of options and alfalfa still available and the milk tastes great whether browsing or not... and customers have raved on how good mine is vs others... so it might depend on what you have available for browse and if they have other feed avail.
I grain with just whole oats and a bit of boss or corn (trying to get away from corn)...
my goats only get molasses post kidding....