Cows (HM)

Cost: 5000 G each.

Profit: 150 G for Small Milk, 250 G for Medium Milk, 350 G for Large Milk

most productive Days to break even = 33

Care
New cows are purchased as calves. They do not require food, but do not produce milk. You should talk to them and brush them every day, to increase their affection.

After 21 days, a calf will mature into an adult, and can be milked, but also starts to need food. You should also continue to brush and talk to it. The higher its affection, the better and more valuable milk it will produce.

A cow in this game will eat either Fodder or store bought Cow Feed. Cow Feed costs more overall, but can be purchased in any season and used immediately. To get Fodder, cut it from Grass which you can grow in your fields from spring to fall.

Affection
Affection is a hidden value in the game that determines the quality of milk. Other than the size of the milk, you normally have no way of checking what your cow's current affection level is. Using the quick ending trick however, you can view your cow's affection levels at the end of the game's result screen.

Affection mechanics spoilers:

Milk Quality
The quality (size) of the milk depends on the affection your cow has towards you.

If you brush and talk to a cow every day, then upon maturity, it will have 84 affection, producing small milk. After another 3 days, it will reach 96 affection and switch to medium milk. 24 days later, it should start producing large milk. You can then stop brushing it, if you wish, although the stamina cost of brushing is minimal. Continuing to talk to your cows is useful, as your final score will be influenced by each cow's affection; for maximum score, you need at least one cow at maximum affection (255), and the others at 200+.

Breeding
Calves and baby cows do not need to be fed.

A cow is also necessary to trade to the Traveling Salesman in exchange for a Magic Bean (HM).