It is called Fur-farming
Air is trapped between the hairs of the animal's fur, and the body heat of the animal warms that air. Thus, the animal has a layer of warmed air next to their skin keeping them warmer than if they had no fur.
fur
A person who hunts animals for their fur is called a fur trapper.
In general they are called mammals.
The fine hairs trap warm air close to the skin - keeping the animal warm in winter.
Killing animals for their fur is called poaching. They shoot arrows,throw spears or they just get sword or knife and start stabbing And then they scrape their fur off its a bad thing
A person can wear a coat in cold weather to keep warm. It is the same principle for animals that have feathers or fur.
I would say no, but I don't know how you think. Are you keeping them for pets? Fur? Meat? If pets, don't. They are wild animals, and there are domesticated rabbits for your pet needs. If fur or meat, depending on the size of the pen. A regular pen for two pet rabbits are too small for breeding rabbits. If on a large large field, could work, but why? Is it even legal? The space they will need in time in an enclosure is difficult to fix. And it is certainly not profitable, or healthy for the rabbits.
polar bears
There are few different types of groups of animals that are warm blooded and have hair or fur. The largest group of warm blooded animals are tigers and coyotes.
It's based on what type of animal your talking about. Fur, is used for keeping warmth and sometimes blending in. for example, a fish doesn't need fur because it lives in the water and is cold blooded, so what would be the point of fur? On the other hand, a wolf needs fur because during the winter they need to be warm because their not cold blooded like fishes are.
We have been, as a a speices, smart enough to make clothing long enough that we have evolved away from needing fur, now I just have to worry about keeping it on top of my head.