Depending on their parents and how good the mother was and how much milk was produced 3-5lbs. I had some issues with my first two litters and average weight for my NZW(doe) and a NZW/Cal(buck) kits were 4lbs at 9wks. :x The breeder I got them from was producing the same kits but at 8wks they were every close to 5lbs. I have 3 litters due this month so time will only tell. I have a NZW/AmChin doe that is 6month old and she only weighs 6.5lbs.
Are you breeding for show, meat, and/or fur?