What do sheep eat?

Here in Canada, my uncle has some sheep. Mostly, they eat grass and clover from the pasture. They will graze all day long. During our long winters, they eat dried grass, which is called hay. Sometimes he gives them a little bit of grain, like oats, for extra energy, especially the mamas. They also need access to salt and special minerals to keep them healthy. They are herbivores so they only eat plants.