There are three Animals available in the game - sheep, cows, and chickens. The silo outside their houses shows how much fodder is left to feed them. All the animal barns have pastures behind them and require a certain amount of grass planted before you can buy animals.
You can check your animal happiness by going into your system notebook (Press SELECT twice) and then picking the animal you want's option. You can find out your animal's current size, whether it's grumpy or happy, it's happiness rating, and how long is left before it gives birth, in the case of cows and sheep.
There are four stalls for cows in the cow barn, and a fifth that is used for pregnant cows. A cow takes 30 days to give birth. A cow can be made pregnant using the M. Potion.
If cows are kept happy and healthy, by being talked to, fed and brushed every day, they can be milked for up to 250G. A butter and cheese maker can be added later on to the barn, with profits of 300G. A cow with 8 or more hearts will produce Large Milk and a cow that has less then that will produce Small Milk.
Using a bell, you can attract the cows out of the barn to graze on their pastures. Leaving cows outside overnight makes them unhappy for 3 days, as does leaving them out in the rain.
Chickens require 9 bags of grass to be planted.
You can keep up to 4 chickens and they can be put outside using the Whistle to find their own food.
If they are healthy and happy, they lay eggs that can be sold for 50G. You need to feed your chickens every day in order to produce eggs, and they enjoy being picked up.
Using a link cable, you can connect to another person who has Harvest Moon 2 and trade chickens. There is a chance you will get a golden chicken, which lays eggs for 500G each. The chicken itself can be sold for 10,000G.
Sheep were a new addition to the Harvest Moon games. You have to have Ken build you the sheep barn. Ken requires you to have 800 pieces of wood and 70000G before he'll build it for you. The sheep barn takes him about 8 days to finish.
The pasture needs around 16 bags of grass for Chet to let you have sheep for 5000G. You should also buy the Shampoo, which acts just like the Brush on the cows. Using the Brush on sheep doesn't have any happiness affect, so you need to use the Shampoo instead. Your first sheep will be medium size, and they take 22 days to grow into adult sheep. After that you can harvest the wool that grows on the sheep.
At first you'll get small pieces of wool, which sell for 200G a piece. Eventually when your sheep have a higher happiness rating you'll be able to get large pieces of wool, which sell for 250G a piece.