So I started a new play through and decided to do it full vanilla. I was lucky enough to run in to a 2 star boar relatively early. While I know we need to be around the animals so their taming progresses, It seems like we need to be around for them to breed productively. I didn't really test this except for in game play. The boar farm is quite a ways from my base so I travel there and back via portal. first time i left food with the boars and left to go about the business of mining copper. After a few days i returned and there were only 5 boar bred. I decided to feed them the same amount of food and stay in the area to see if they would breed better. I stayed next to the farm for about 3 days and nights and the result was around 20 or more boars bred. they went to town doin' the nasty. they seemed to alternate on which one bred. while i was bored out of my mind, i did get a nice screen shot of a piggy being born and dropping from the breeder. I don't know how to embed the screen shot in this post.

Has anyone else noticed if their tamed animals breed less if you're not around?