I’ve raised them without any “bought” feed, just a mineral block which I make sure each of them have and fresh
water daily. I make sure they get something high in protein, especially for growing kits, or pregnant or nursing does. Over winter is a little harder because I don’t have much fresh weeds for them, but they get hay free choice daily in their feedback and whatever greens I can find. Clover in moderation, with other foods, or Greater ragweed, purslane, as a source of protein. Not only do they survive on this, they thrive. Secret is in getting a well balanced diet for them. Look up forages and you’ll be surprised at the high protein items that are not alfalfa or clover. Some are even higher than alfalfa. Dry some for winter feed for them. I give them greens from the garden too, the occasional carrot, they love radishes and their tops, collards, kale, but not too much, it can cause indigestion.