How do you feed cows?

[GazimoEnthra]

The cows say they want crops, I've offered them everything I've grown but they won't eat anything. Any tips?

[Fulano]

They eat pretty much anything grown... I usually use the glow tulips because they are plentiful. Hold it in your hand and they come eat it out of your hand.

You can make a feeding trough at the livestock bench to keep them fed.

[Nakos]

Build a Livestock Workbench, and make Feeding Tray.

https://core-keeper.fandom.com/wiki/Livestock_Workbench
https://core-keeper.fandom.com/wiki/Feeding_Tray

Or, put a (plant) food item on your hot bar and then hold it in your hand and stand still (the animal will come up to you and eat it).