I actually feed 4 oz sunflower seeds, 4 oz generic calf manna, and 8 oz wet cob to everyone. Does on the stand get straight wet COB depending on condition on production. I own a dairy and have milked for 12 years and this is the best feed system I have come up with.
I mix my own and all my does get the same feed. It's equal parts barley and oats, wheat bran and BOSS. I have Nubians and feed my milkers about 3 quarts a day and they give around a half gallon of milk per goat. I would up their feed when you start milking and keep an eye on them to make sure they aren't gaining weight.
I feed mine a dairy cow pelleted feed year round. I can bounce between the 16 and the 20% protein as needed. The 20% feed about a month prior to breeding to flush them, but mostly it's the 16% protein, high energy pellet. In the winter i add soaked beet pulp.