I think there are many correct answers to this question. It depends on where you live, what browse they have, what minerals are in your soil, etc.
We are not milking any of our Boer or Mini Nubian goats but we have over a dozen nanny goats who are nursing baby goats. We feed our doe pasture a grain mix 2 times a day. I tried once a day but it wasn't enough, they didn't look healthy. We also offer free choice minerals and unlimited hay. I often take them for hikes so they can browse. I copper bolus our herd 2 times a year. I realize this is very general nutrition information but no matter what you decide to do you will need to tweak it to fit your herds needs.