Cage size depends on rabbit size. Florida Whites can be in a smaller cage than Flemish Giants. That being said, the rabbit should be able to take a couple hops from end to end and stand up on it's hinds in the cage. Your breeders should have out of cage time if possible. You can give rabbits ping pong balls, timothy mats, pinecones to play with in their cages. Whatever kind of cage you use, make sure it's easy to clean. Some breeders rebreed at 4 weeks after kindling. I avoid the hottest and coldest months of the year so max breeds per doe is 3 for me. A good rabbit pellet is the easiest feed. Many are going with fodder these days and I'm definitely going to try it. Timothy hay is a favourite treat for my guys. If you aren't using a pellet, make sure you account for vitamins and minerals with a supplement. If you are on Facebook, I suggest the backyard meat rabbit page. Good people who care about their animals and very helpful.