I have Oberhasli dairy goats. Jerky (honestly it was his name) was born in April so he is 9 months. I put it off because of the holidays. I have goats for milk and show. The "extra boys" are going to be fed out for our freezer, other freezers and pets. I will get stats on what his weights were when I pick up the meat.
Just like beef. You get more meat out of a meat breed than you do a dairy breed. If all you want is meat go with a boer or a spanish. If you want both go with a dairy meat cross or a breed like it and if you want to deal more with the milkers and eat your extras... pick a breed that appeals to you.