Take in hand (bag → “In hand”) wheat, corn, straw or fodder: chickens, sheep and cows that like it will follow you (♥).
Lead them to your plot: they belong to you, nobody else can kill them.
Fences and gates for the pen (players can go through gates, animals can’t).
Fill a feeder with fodder (2 wheat + 2 straw → 3 fodder, at the workbench): animals within 4 tiles come and eat.
Chickens lay one egg a day on a claimed plot (a one-in-five chance elsewhere); when fed, they sometimes hatch a chick. Fed animals: you shear sheep (shears in hand), you milk cows (bucket in hand).
When hunting, the loot depends on the size of the animal (meat, hide, wool, feathers, fur).