Chet's Animal Shop is located in the lower southeast corner of the village. He is open Monday through Saturday, from 6am to 6pm. Chet sells you animals and products to take care of your animals. You can also sell animals back to him.
Chet is a big animal fan, so he wants you to take extra good care of your livestock. When Chet sells you an animal, he makes sure first that you have enough grass planted in the back pasture area of each barn. If he feels that you don't have enough grass, he'll tell you so and refuse to sell you an animal. The amount of grass needed varies from each of the three animals. For cows, you need to have at least 6 plots of grass planted (a plot being a 3 by 3 square of planted grass). Chickens need 9 plots of grass planted. Sheep need a lot of grass planted! Their entire back pasture area needs to be covered in grass, which could use as much as 16 bags of grass seed.
When you buy your first animal of a certain kind from him, he'll give you a gift to help you bring your animal inside and outside of its barn. When you buy your first cow, he'll give you the Bell. Your first chicken results in the Whistle, and your first sheep results in receiving the Horn. These three items allow you to call your animals outside into the pasture area and back into the barn. To call your animals outside, have the animal specific item as your active equipment and press the A BUTTON. The screen will fade out and when it fades back in, your animals will be standing outside in their pasture. To bring them back inside just go into the barn and use the item.
If at some point you run out of fodder for your animals, you can buy a bag of food from Chet. The bag of food only lasts for a few days, and you can't buy multiple bags. So if you bought a bag of sheep feed, you'll have to use it all up before Chet will have another one available for purchase.