I have an 8' x 10' barn for my four Nigerian Dwarf does. It's actually up on bricks so it's off the ground; the floor is made of wood slats with spaces in between each piece. I have three stalls that I leave open during the fall and winter. When kidding season has arrived, I'll put each doe & her kids in their own stall. Each of my stalls is about 4' x 3'. live in Texas, so I make sure to have fairly large windows for air flow. My doe barn has three windows, but they are big enough for air -ventilation. Ventilation is very important because a goat barn is going to get dirty quick, even with constant cleaning. You want to be able to air-out any ammonia smells and be diligent about mucking out the barn.
I have my buck, wether, and another doe in a 7' x 7' or 8' x 8', I don't recall at the moment. Currently, I have just one small stall (for feeding purposes only right now) in the buck barn. My buck barn has four windows that I can leave open or nail a board to when it gets really cold. I I only bed down my barns with hay when it is really cold out under 50/60 if I have kids and under 40-50 if it's adults. The roof slants on both of the barns. They are both at least 5' tall so we can go in and out as need be.
I live on just under and acre so, unfortunately, don't have any grazing room for my goats. I give mine free-choice coastal hay along with a mix of grains that are topped with loose minerals and dolomite. You might want to check and see if your area is sufficient or deficient in copper and selenium, both very important minerals for a goat's health.
I didn't breed my does till they were 15-18 months old. That is my personal preference for when they were old enough and matured enough to be bred and have their own kids. I wouldn't suggest breeding younger than 12 months. As far as the number of kids a Nigerian Dwarf, I'd really say it depends on the goat and the breeding. Nigerians are known, however, to have multiples; triplets and quads not being unpopular. My does have only had trips and quads the each time I've put them with the buck. They have all come from multiple litters, I suppose you can say, too.
I thought you had to breed Nigerians every year, till I met someone who didn't seem to follow tradition. She actually milks some (or all, I don't recall) of her does for about two years! Now, you are going to have to be on top of milking to get that good of production from your does. They will need to be milked twice a day without fail. My friend actually went to once a day milking then switched back to twice a day. She has truly inspired me to try this out with at least one of my does!
I'll try to get some photos up later, but if not, I hope this helps you out! : )
