Feeding your animals is not only important for their survival, but your survival too as they provide an important source of food for yourself. Therefore, it’s pretty important that you know how to feed them as soon as you get them.
How you feed your animals depends on what kind of diet they have. For example, if your animals are Herbivores you can simply leave them to graze on the grass outdoors. Of course, sometimes the weather doesn’t allow for them to head out and so you’ll need to ensure you have some Hay. Once you’ve got some Hay simply leave it in their allowed area and they’ll eat it whenever they’re hungry. You don’t have to do anything else apart from that.
Carnivores such as Wargs or Timber Wolfs on the other hand, live on a diet of raw meat and so. Just as you do with herbivores, all you need to do is place the raw meat or human meat within their allowed area.
That’s all there is to feeding your animals in RimWorld. Be wary though, sometimes animals will feast on consumable items if they’re within their allowed areas, so be sure to move these out of the way to avoid missing food supplies.