What do people really feed their guinea pigs? It's different for everyone and depends on what is in season, whether you are interested in foraging for greens, and what you think is good for your guinea pig, not to mention what your pig is willing to eat. Every pig is different: some have medical conditions requiring special diets. A few pigs don't like cabbage or cilantro. Others hate tomatoes (a staple in my home). Who knows what will turn your pig's head? Whatever you offer your cavies, introduce foods slowly, offer a variety, and be sure to provide unlimited high quality hay and plain pellets.

Source: Guinea Lynx