During most of the beginning of the pregancy, they just get their standard amount- for two living together about 1 scoop of mix (sheep mix), plus some barley and some dairy nuts morning and night. Then in the last 6-7 weeks, start to increase how much they get gradually, by a 1/4 of a scoop at a time. Thats when we start giving goatlings some goat mix. By the time they kid we are giving them about 2 scoops morning and night, each, as opposed to together. We also give them an extra feed at 5pm, either alfalfa, chopped up veg (carrot, apple & cabbage), or soaked beetpulp.
For the alfalfa- either molassed or un-molassed, we have fed both, they seem to like the molassed stuff better. We also feed cattle dairy nuts- if yours are used to nuts, then it might be worth seeing if you can get hold of some.
Beth