Part of the mood mechanic for animals, which is stated by the wiki, says... I think this is a very unfair effect which doesn't make much sense. I'm not sure if this is because the animals get cold or what, but it that is the case, it can be avoided by going to sleep before 6PM. I believe a heater does remove this effect, but in my opinion we shouldn't be using a heater for warmer months. Also even if so, a heater shouldn't be able to keep up with a wide open door. So my suggestion instead of having this effect is... If a barn or coop isn't closed before you go to sleep, all animals within that barn or coop should get a heavy mood penalty even if a heater is present. In fact, I thought that's how it worked originally until I started getting random products from my animals which I believed were taken care of correctly. The penalty should make sense because you're leaving open a draft to get into the coop or barn, which I'm sure the animals wouldn't like. It's a simple and easy fix that can't be avoided. A heater would then be for solely winter.
I could be wrong but I think the mood issue was a bug that got fixed with the last patch. I don't think I've updated so I can't tell for sure but there was a thread a while back where a bunch of us were discussing this exact issue. The game's mood mechanics were causing the animal's happiness score to actually roll over overnight and put the animal back at a low score, essentially punishing the player for taking good care of their livestock. You'd do everything you were supposed to - pet them, let them out to eat grass, close the barn doors at the end of the day after they'd gone back inside...but if you didn't go to bed at the right time, you'd get low quality product the next day. It was bananas. Edit: Found it: http://community.playstarbound.com/threads/psa-major-animal-bugs-issues.126444/
It's still happening to me and I have the latest update. I just recently got a heater and all my products went from being random to mostly golden stars.
Ah, yeah I have no idea then, like I said I don't think I ever grabbed the latest patch that supposedly fixed it. Just wanted you to know you aren't alone in your opinion, there's quite a large group of us ranchers on here who are equally perplexed by the way the game calculates mood. lol
