An Animal Pen should come after an Animal update. The Animal Pen comes in 3 (maybe 4) sizes. It will start small then get bigger as you upgrade it for more containment.
The Animal Pen is typically a containment for domesticated animals, or containment of herded animals for domestication. Small Animal Pens will hold up to 2 cows. Medium Animal Pens will hold up to 5 cows. Large Animal Pens will hold up to 15 cows. Massive Animal Pens will hold up to 40 cows.
Small Animal Pen: Medium Wood x10 + Plank
Medium Animal Pen: Small Animal Pen + Medium Wood x4 + Plank
Large Animal Pen: Medium Animal Pen + Medium Wood x6 + Plank x2
Massive Animal Pen:
New recipes that come with Animal PenEdit
New measurements that is needed with Animal PenEdit
Horse: 2 Cows
Cow: 4 Chickens
Chicken = Dog = Cat