hmmm yes i guess full domestication would take a lot of writing but i just thought of a system that may be simpler, it includes the buildings of course. the ability to build a stable, and the ability to build an aviary. how it works is, and i know we can do it the old fasioned way but. there would be a double gate/door on them and i'll explain how the system would work. already in the game, animals can go in and out of town along roads too. now if a person was to build a stable and open the outer gate and wait for an animal to walk in checking periodically and when it does, lock that gate and open the other until the animal is in the main area then put the gate like they were before, preventing escape and alowwing more to be caught. benefits of doing this , well they can still breed and cannot escape this would be a way of keeping a heard of probably mixed animals unless you took your time to only let one kind in, that would be safe from overhunting. need the aviary because birds can fly out of a stable. and naturally like in any other building you can build rooms, hahaha make a zoo if you want and live there too

just thinking that allowing animals to come and go from buildings like they do from towns and roads might be easier to program and satisfy some of the domestication idea.
or alternatly just make one new building called a pen, and program the building to allow animals to walk in with the double gate idea or we could just build a pen in a pen.
in anycase, true domestication went in steps not a big leap. by the time the full domestication could be programmed if that is planned, starting with smaller simpler things might creat a more natural progression in the societal development of domestication.