Hay is the most important part of a guinea pig's diet.  They have a very similar digestive system to horses and rabbits, and other hindgut fermenters.  A diet rich in hay helps prevent dangerous slowing of the digestive system, otherwise known as G.I. stasis.  Hay also helps wear down guinea pigs' teeth, which are constantly growing.

  Hay should be grass-type, such as timothy, orchard, meadow, or oat hay.  Alfalfa should only be given to babies and can cause bladder stones in adults due to its high calcium content.

  Guinea pigs should always have access to hay, and should be offered approximately a handful the size of their body each day.  At Lost Woods, we'll give hay first thing in the morning to encourage everybody to start their day off eating the healthy stuff.  We'll offer fresh greens and veggies later in the afternoon, and top off the hay in the afternoon/evening.

    To cut down on wasted hay, we stuff hay in tissue boxes or other cardboard boxes when we feed it to the guiena pigs, so it stays clean and dry.  Garbage-bag boxes work very well for this too.