I was very surprised when I saw a listing selling four-week-old bunnies this week on Craigslist, suggesting them as Christmas gifts with a few in a Christmas decorated box.They certainly are irresistibly cute at that age!
There are many thoughts on when to wean young kits from their mother's milk, which means when to separate them from their mothers also. When it comes to rabbits, we often look how rabbits do things in the wild because those instincts still drive the domesticated rabbits of all breeds. Whether the mother leaves them or they leave on their own at three to five weeks, young wild rabbits can get what they need nutritionally on their own. However, the reality is that young wild bunnies are quite vulnerable to predators who also need to eat.
Many breeders wean their bunnies at four weeks and there is nothing particularly wrong with that practice when the breeder's purpose is to keep or sell to other breeders the stronger and faster growing of the kindle and cull the rest. However, I have known bunnies weaned at four weeks to lose weight or not have any weight gain for up to a week, suggesting to me that they were not quite ready to be weaned and the mother was still producing enough milk for them. Healthy ones will bounce back on track with weight gain and, perhaps, a little stress on a bunny gives some clues about which ones are keepers in a breeding program, but I am generally not in favor of weaning at four weeks.
What I do find more concerning is that a few breeders will even sell bunnies at four weeks of age if their state allows it. My state currently has no age restrictions, but a growing number of others do. I am not in favor of more laws, but when people are not being responsible...well, that is why laws are made.
As of the writing of this post I found that it is illegal to sell a rabbit under eight weeks old in North Carolina, Vermont, Washington DC, and in Houston and San Antonio of Texas. Some laws read it is illegal to sell a rabbit under two months old: Arkansas, Phoenix of Arizona, Los Angeles County of California, Delaware, Florida, Indiana, Kentucky, Annapolis and Rockville of Maryland, Montana, New Jersey, New York, Pennsylvania, South Carolina, Tennessee, Gainesville of Texas, Virginia, Washington, and Wisconsin. Many of these laws do make allowances for selling larger quantities at under the age limits, usually over six at a time, and some specifically name for what use rabbits cannot be sold under the age limits, such as pets or companion pets, but omit for breeding or livestock purposes. (Reference: WabbitWiki's Rabbit Sale Laws in the US)
One problem I see in particular with the practice of selling a Silver Fox bunny at four weeks as a pet is that Silver Foxes are meat rabbits, which means that they are meant to grow to be around 10 pounds and even more. I have a doe that looked on the small side and sweet at eight weeks when I got her, but she is one of our largest rabbits and not quite so sweet until she feels secure. Silver Foxes typically have a docile temperament but they can be a lot of rabbit for a pet, especially if for a child who has not had one before. We once gave an eight-week-old New Zealand White to a 4-H family, who had pet rabbits before, but even though we warned them how big the rabbit would probably be fully grown, they later told us—with complete looks of amazement—that it had gotten too big for the indoor cage in the following weeks.
Being that we have had New Zealand Whites before Silver Foxes, I can say that Silver Foxes grow a bit slower than NZWs and possibly develop slower as well, so perhaps they need their mother's milk a bit longer. Although we do not wean even our NZW purebreds as early as four weeks either.
We try to leave the bunnies in with the mother until they are six to eight weeks old, unless the kindle is large and crowding is an issue. We have roomy cages, but we have had NZW kindles of twelve surviving to weaning and, as they grow, they take up a lot of space. If we feel we must separate them earlier, it is done no earlier than five weeks old and then we take out only the largest, which gives the smaller ones more access to the mother's milk.
It may not be as cost effective, but we prefer to separate bunnies at around six to eight weeks so they are fully weaned and their mother ready for the next breeding. We feel it is the healthier breeding and weaning program for our rabbits.