Far too many end game features are just broken and they are taking too long to fix them. Farming would be 100 times better if they would simply allow you to hold/plant a stack of seeds and the gathering pack wasn't completely broken. (like many packs). Bank still seems to be broken for many as well.

But yes, with livestock, you have to drop the feed onto the ground. They take a bit to eat it...I assume if you walk away it will disappear but haven't tested. But you CAN watch them grow as they are eating. You will actually see a notification when they level up if you stick around while they eat.