Usually if you put out a plate of the veggies they will pick and choose what they want to eat. Make sure you remove the veggies that they may not have eaten daily. They are no good after a few hours, they become wilted and for the lack of a better term, yucky. A variety of veggies that are good for them are leafy greens such as dandelion greens, kale, spinach, parsley, romaine lettuce, bell peppers and the occasional baby carrot. Go to guinealynx.info/healthycavy.html#diet to read a bit more about a "proper" diet for piggers.
I'm curious ... does anyone know any tricks for freezing veggies? It seems that my vegetables go bad before I am able to use them ... so I thought I'd just make a bunch of daily containers and freeze them. Unfortunately it seems that most of the veggies once they thaw are limp and ... well ... disgusting. Is there a trick to freezing a carrot or can it just not be done?
Use a plastic bagging with "sealer slip", and use some plastic straw to empty the air inside and pop it in the freezer, that's what my mom do in a salad blah blah blah, and it seems so fresh when its defrosed.