My recollection is you need to "talk" to each animal once a day, every day.
Stardew Valley
All things Stardew Valley.
I just assumed it was petting them. But yeah, walk up to them and press a button and look for a heart. Do it every day. If there's a grey storm cloud thing instead of a heart then they are grumpy, make sure you didn't lock them outside overnight, make sure they have a heater (especially if it's winter), make sure they have food.
Oh.
Any idea how long?
Make it a habit to check on all of your animals every day. You'll keep them happy and youl want to see if they produced anything anyway.
Yea, I do that
Have a lot of excess eggs. Milk not so much
How many hearts are needed for the large products? Its the only thing I need for the greenhouse and to begin my ancient fruit farm
Premium drops are random, determined by a formula that takes into account friendship, mood, and daily luck (for ducks and rabbits). There's no clear cutoff value. More is better, of course.
What platform do you play on?
If you play on PC there are some mods that can help you figure out if animals need to be interacted with and how many 'hearts' you have with them.
I play on switch. In an emulator
Ah, okay.